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How do we loosen tension on a BMW E39 front window regulator anyway?

49K views 67 replies 12 participants last post by  bluebee 
#1 · (Edited)
EDIT: MatWiz helped us focus on the spring in order to come up with a nearly effortless technique (see post #25, patent pending) which easily loosens & tightens the tremendous cable tension notch by notch.
This almost effortless tensioning method is not documented anywhere else on the Internet to our knowledge!

What is the trick to loosening the tension on a BMW E39 front door window regulator where the cable has jumped off the wheel?

If it's obvious how ... I don't see it.

Here is my 'bench' test apparatus:


And, here is the problem:


Q: What's the procedure for loosening the cable tension to get it back on the last roller?

NOTE:

1) This was the original bmw 2002 525i E39 front driver side window regulator repair DIY
2) This was an update that added the window regulator a year later
3) This is yet another update that attempts to detension the window regulator
 

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#2 ·
this job is super hard... I ended up cutting the rubber spring that work as a cable limiter/holder when goes in to the center loop, but this just to get reassemble the whole thing. I haven't tried to test it so I have no idea whether it works or not

I would like to know how too.. otherwise we all have just stick to "Just buy OEM part, dont fix it or buy aftermarket ones"
 
#6 · (Edited)
I would like to know how too.. otherwise we all have just stick to "Just buy OEM part, dont fix it or buy aftermarket ones"
I don't see anything wrong with the regulator so I'd rather figure out how to release tension.

Plus, I've googled and I don't (yet) see any other threads showing a stop-by-step way to release the tension ... so ... if we, together, come up with a good idea, the resultant DIY will benefit those who follow.

If you compress the spring, does that introduce slack into the cable system?
Let's make mechanical spring compression "Plan A".

I'll check and report back.

the wheel has a broken section of the flange
The wheel is chipped, but, I don't think that's why the cable slipped off the pulleys because the tension is astronomical, which should keep the cable on the pulley (I think). Of course, if the wheel truly 'is' the problem, the regulator is toast, and the solution morphs to a simpler solution because I can experiment with releasing tension without being worried about further damage to the regulator.

So, even with a chipped wheel, the problem still remains ... which is to figure out how to cleverly release tension.

What I ended up doing is removing one of the cable ends from the slot it sits in next to the motor (where the cable spring is), which created enough slack
I've seen Matwiz' DIY showing the coiled insides of the motor so, I understand what you're saying (where is the wiz when you need him!).

I assume disassembling the motor is "Plan B".

it's a bit tricky getting it back on the internal pulley.
Looking closer at the motor, I see this 'purposeful' plug.

I wonder ... Do you think 'this' can be used as 'Plan C" to loosen tension somehow?
 

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#3 ·
BB: I haven't done this repair so this is pure speculation:

In your first picture, there looks to be a spring on the cable assembly (near the motor?). If you compress the spring, does that introduce slack into the cable system?

In your second picture, it looks like the wheel has a broken section of the flange at the 7-8 o'clock position. Did the cable jump the wheel during operation? If yes, that broken flange may be why. It may need to be replaced or this could happen again.
 
#4 ·
I don't know how this applies to the front regulator, but I just had it happen to my rear one. I tried placing the cable back on the wheel, but it just seemed impossible. I opened up the motor where the cable goes in/out and saw that there was some additional slack of the cable caught looped inside, which also prevented the motor from moving either direction. After fixing that and assembling back the motor it still seemed like I need to apply a lot of force to get the cable back on tracks. What I ended up doing is removing one of the cable ends from the slot it sits in next to the motor (where the cable spring is), which created enough slack in the cable to loop it around all pulleys, and then wrestle the cable end back into the slot and it worked. What surprised me is how much tension the system rests/operates under and with all plastic pulleys and steel cable...
 
#8 ·
Oh no, you did not heed my warning about how hard it is to re-assemble in your original post! But wait, did the cable just come off while in operation?

I wanted to mention in you original post that the chip might be the end of the regulator unless you replace the roller which is why I suggest a call to RegulatorUSA.

Did you call the regulator guy in Brooklyn to see if he sells just the rollers he uses?

I think the cable will still jump off the roller if the chip is not fixed. Reason being, the cable is under great tension as you found out. The cable itself has a tendency to want to recoil naturally so as the cable moves around the roller, the cable twists, as it twists, it will jump off the roller. Remember, the cable is nothing more than twisted steel wire and twisted steel has the tendency to twist in the direction of the winds.
 
#9 · (Edited)
did the cable just come off while in operation?
The cable came off in testing - but I don't think it was due to the chipped roller; I think it was because I had not tightened everything - and/or because the window was out of adjustment, as there is not a well defined procedure (despite the Bentleys, which are worse than confusing) for adequate adjustment of the stops.

BTW, I pulled out the square plastic bolt - but it doesn't seem to be of any benefit in loosening the tension. All it does is plug the hole, perhaps so that we can add grease to the motor helical gear.


At some point (I don't know when), the smaller springed tube fell out of its slot in the motor housing.


In hindsight, here is how that tube 'should' have been reassembled:


Another mistake I made (of many) was to not realize that this ribbed black plastic spring-tension adjuster might be a critical component in loosening cable tension!

I should at least have marked the initial location of the black plastic large spring stop, so that I would know how much to push it back into the motor when I put it back.
Here is that black plastic ribbed spring stop, almost pulled out:


I spent some time trying to figure out how that larger black plastic stop goes into the motor - and finally concluded it's a press fit - which takes a LOT of force to fit inward - and which is mighty hard to perform with that heavy spring in place (more about how to conquer that all-important heavy spring comes later).


Boing!

While I was examining the motor for how to release tension, curiosity got the better of me.

This gear is what spins the coils of cable.

Notice each coil is wrapped around the takeup spool twice, in opposite directions.
The large spring cable is coming in from the left; the smaller spring cable comes in from the right.

Within seconds of snapping that photo for you, as I put the camera down, that nice arrangement of cable coils literally unwound in my hands.

Leaving me with an unsprung front window regulator takeup spool.


After all this - I belatedly realized (what might be) the trick to reduce tension on the front window regulator!
Look at this picture below.

Notice you can easily unhook the heavy coil spring from the cable, and hook it back up easily after the fact, simply by unwrapping it from the wire as you would unhook a key from a common keychain.

I'm guessing this spring unwrapping can be performed without disassembling anything!

If so, that's the trick to releasing tension (WITHOUT DISASSEMBLING ANYTHING!)

It's too late for me to try this trick - but - if I had known that I could simply unwrap the heavy coil spring, I would have tried that, instead of ending up with motor parts all over the place.
 

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#10 · (Edited)
I practiced removing the spring off the cable a few times.
Of course, strong tension is gone - but, I proved to myself the concept of removing the spring without disassembling anything is sound; so, here's my proposal (for the next person) of the trick to loosen cable tension without disassembling anything else:

To loosen cable tension, this may be the best potentially viable approach:

  1. Measure the current location of the black ribbed plastic large-spring stopper
  2. Push the black ribbed plastic large-cable stopper in all the way
    • That, in and of itself, may provide enough tension relief
  3. If not, first, you may have to pull the black ribbed plastic large-spring stopper out an additional inch or so
  4. Then, unwind the large spring off the cable (like pulling a key off a keychain)
  5. When it's time to replace the spring, wind it back on (like putting a key on a keychain)


Had I known that potential trick of unscrewing the large spring, my regulator would never have been taken apart ... but ... I guess someone has to take the hit so that the next person has an easier time of it.

The good news is I now know more about this window regulator than I ever wanted to know - and I certainly have learned a host of things NOT to do!

The bad news is that it would take a minor miracle to get it all back together again.


Things not to do:

  • In hindsight, I wish I had marked the location of both window clamps to the guide rails because they probably need to be symmetric on the rail cable guides when I restring the cable.
  • Also, I wish I had marked the amount of cable wound inside the spool because that is probably a critical dimension (I should have put a dab of nail polish on the two cables at some strategic point)
  • I wish I had marked the original length the black ribbed plastic large spring stop stuck out of the motor (as it can move at least an few inches either way).
I'll ask MatWiz for advice how to proceed ... he (Dan) seems to be the only one who documented the motor disassembly (but he stopped half way when his camera battery died):
-> E39 (1997 - 2003) > Front Window Regulator - Re-Assembly Instructions.

 

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#11 · (Edited)
Another mistake I made (of many) was to not realize that this ribbed black plastic spring-tension adjuster might be a critical component in loosening cable tension!
You are right. It IS critical to loosening and tensioning!

I should at least have marked the initial location of the black plastic large spring stop, so that I would know how much to push it back into the motor when I put it back.
Here is that black plastic ribbed spring stop, almost pulled out:
No need to do this, that thing is self adjusting, self tensioning!

OK, this was 5 years and 2 months ago, so I might not remember everything I did so this is to my best recollections. (Damn camera battery!).

IIRC, the black rigged piece works counter intuitive. The spring pushes it out. When the spring pushes out, the tension increases on the cable.

Also, the black piece works like a ratchet. Once it is pushed out one ridge by the spring, you can not push it back in. Or is it the other way around? I don't remember which way the ratchet works, but I do remember that it is a ratchet.

So the trick was to hold the spring compressed as much as I could, then put everything in its place, and then release it to create the tension. The tension is not adjustable, the spring creates the tension and there is nothing you can do.

I hold the spring compressed so that I have some play with the cable, so that I could put all the parts and the cable in its place, I used a kitchen fork. Stick the fork in the spring and push it against the metal housing. I had to bend one of the middle fingers of the fork to allow it to go around the black piece.

To my best recollection, I put the cable around the rollers, then compressed the spring, and only then pushed the spiral wheel into its housing.
 
#14 · (Edited)
It IS critical to loosening and tensioning!
So that's the answer to the question of how to loosen cable tension!
I wish I had known that earlier - when I needed it!

The good news is the NEXT person can start without making the same mistakes!

IIRC, the black rigged piece works counter intuitive. The spring pushes it out. When the spring pushes out, the tension increases on the cable.
Is this correct yet?

  • Push the black plastic ribbed post into the motor ==> decreases cable tension?
  • Pull the black plastic ribbed post out of the motor ==> increases cable tension?


the black piece works like a ratchet. Once it is pushed out one ridge by the spring, you can not push it back in. Or is it the other way around? I don't remember which way the ratchet works, but I do remember that it is a ratchet.
I agree it's confusing. Like you, I found the ratchet post does NOT spiral inward. Each "rib" is a 'stop'. However, I found, with force, the ribbed tension adjuster 'does' go both inward and outward - but it takes a LOT of force either way. I had to actually use a mallet on it, which is difficult because the spring was there (this was before I knew HOW to unwind the spring in situ!).

So the trick was to hold the spring compressed as much as I could, then put everything in its place, and then release it to create the tension.
Another trick 'might' be to assemble the cables without the spring (taking care to put the black ribbed plastic post in a 'desired' setting), and then manually wind the spring onto the cable like how you put your key into a keychain, spinning it on the cable, one turn at a time.

The tension is not adjustable, the spring creates the tension and there is nothing you can do.
Oh oh. What does that mean? I wasn't confused when I thought that the LOCATION of the black ribbed post is what determines the tension on the cable.

If the spring in and of itself creates the same tension no matter where the black ratchet post is set to, then what does the ratchet mechanism do?

I hold the spring compressed ...I used a kitchen fork.
Do you can see a small hole in the white plastic that the spring goes around in one of my pictures? I tried holding the spring in place with a nail pushed into that hole. However, the spring is POWERFUL. It pushed the nail out - but - with diligence - that hole might be used to hold the spring in compression.


However, I hope that the spring can simply be wound onto the cable as the LAST STEP!

I don't like how the cable is bent
I had noticed that same difference the moment I saw your pictures. Your cable ends in the take-up spool are both straight. Mine are both bent. My cable is also slightly frayed as a result.

I carefully straightened them by hand.


when you wrap the cable ends around the spiral, make sure you insert them flush in their grooves.
I fully understand.

I finally figured to tie it down with these strips until it was assembled.
I had noticed that. I was thinking I might do one of three things to prevent that problem:

  1. Tie it down just like you did
  2. Bolt it down using the original bolts and the original motor mount plate
  3. Skip the step altogether by (hopefully) winding the tension spring on as the VERY LAST STEP! (if that works)
Once one end reaches the end of the cable, the spool will stop, naturally. Turn it the other way and it will stop on the other side. Meanwhile, the spool is always full of cable, either from one side, or the other, or half and half.
Hmmmm.... Interesting!

End to end is exactly the distance that the window is moving up and down. You can't make it wrong
Hmmm... I guess this is one thing I have to try first to best understand!

assemble everything without the spring, but with the black piece.
Well, if my gut feeling is correct, I might be able to assemble the entire thing, and even bolt the motor back to the motor plate, without ANY tension. Then, as a very last step, I will try to wind the spring back onto the cable, from the outside inward (if that will work) just like you put a key on a keychain.

If 'that' works - the tension would be the last step!

the last piece I put in was the spool. I left the spool out, compressed the spring, and then pushed the spool into its place.
Interesting. I was planning on doing the takeup spool FIRST!

This is good advice that the takeup spool can be handled later!

Thank you for taking time to help. I realize it was years ago (your thread was from 2007!), and I'm soooo very glad you posted such great pictures. I scoured the Internet, and, to my knowledge, you're the ONLY one to have done so for the E39!
 

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#12 ·


^^^ I don't like how the cable is bent over there. Something or someone installed that incorrectly or maybe it got dislocated. But look at my picture, they are completely strait:


So when you wrap the cable ends around the spiral, make sure you insert them flush in their grooves.

Another tip, the plastic housing kept jumping out of the metal housing when I tried to put everything together. I finally figured to tie it down with these strips until it was assembled. Then I removed them after.

 
#13 ·
Q: How to wind the spool / spiral?

A: It doesn't matter (!). As long as you 'load' all the groves with both ends of the cable. Once you loaded them, put the spool halfway inside its housing and turn it with your fingers to see who it works. You'll see that as it releases cable on one side into the rails, it will pull in the same amount of cable from the other side. Once one end reaches the end of the cable, the spool will stop, naturally. Turn it the other way and it will stop on the other side. Meanwhile, the spool is always full of cable, either from one side, or the other, or half and half. End to end is exactly the distance that the window is moving up and down. You can't make it wrong as long as you don't leave on groove completely empty, and it doesn't matter from what side of the cable.

I suggest, that for practice and to see how it assemble without the tension, assemble everything without the spring, but with the black piece.

To my BEST recollection, when I assembled everything, the last piece I put in was the spool. I left the spool out, compressed the spring, and then pushed the spool into its place.
 
#16 · (Edited)
closeup picture of the black piece ribs, to clearly show the ribs
Hi Dan,

Here are closeups of the ribbed post. (I'd be glad to snap any photo at any angle you need. Just ask. You're helping me. And the next person. And the next after that.)

It seems to me, as it appears to you, that this mechanism is the missing link.

What puzzles me is why have an 'adjustable' post - when - I've never seen any mention of anyone actually adjusting it?

The post really only 'locks' into place into the motor tube. While it 'can' be pushed down a few notches or pulled up a few notches, it's meant to stay in place once configured.

Since it can be locked in any position ... an understanding of what's different when it's all the way in versus all the way out is key to understanding these window regulators.

My gut feeling is that the post "is" the tensioning mechanism, somehow ... but I'm not exactly sure how. Either that, or it's just for assembly purposes.

 

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#17 ·
Is this correct yet?
Push the black plastic ribbed post into the motor ==> decreases cable tension?
Pull the black plastic ribbed post out of the motor ==> increases cable tension?
Yes. This is correct.

My gut feeling is that the post "is" the tensioning mechanism, somehow ... but I'm not exactly sure how. Either that, or it's just for assembly purposes.
Not maybe. I am telling you that this is the tensioning mechanism.

I just don't remember exactly how exactly it behaves when assembling because it has been such a long time.

But, I just wanted to verify something and it seems that I was correct in my memory. Look at the ribs, that's a ratchet. If I can see correctly in your picture, the ribs are angled in such a way, so that the piece will be able to more easily outside, and will be harder to move back in. The ribs shape like an arrow. Can you see that?

That's why I said that once it moves out one rib, it can not move back. The spring and the angle of the rib prevent it from moving in. And that is the self adjusting mechanism. It keeps the cable tight on the rollers. You can't lock it in place. It is designed that the spring gives it the desired tension, and if and when the cable loosen up in time, the spring moves the black piece out a rib, and keeps the tension.
 
#19 · (Edited)
I am telling you that this is the tensioning mechanism.
Thanks. Too bad I didn't know this before I took it apart - but - let's try to document its function moving forward so that the NEXT person benefits.

it has been such a long time.
I understand. Your DIY thread was posted in 2007!

the ribs are angled ... like an arrow. Can you see that?
Yes. And, empirically, I think it was much harder to pound the adjuster post inward (into the motor) than it was to simply pull it out (out of the motor).

The strange thing is you'd expect the exact opposite!

That is, the spring tension is clearly placing a force on the head of the ribbed adjuster post such that there is tension pulling it OUT of the motor - yet - it seems to stay in place (probably due to the design of the white plastic 'catch' inside the white motor tube?).

So, for whatever reason ... the post is not supposed to go into the motor as easily as it's supposed to be pulled out.

Given that pushing it in apparently decreases cable tension, that would mean that it's designed to allow an INCREASE in cable tension - but not a decrease.

Maybe it's a cable-stretch compensator?

That's why I said that once it moves out one rib, it can not move back. The spring and the angle of the rib prevent it from moving in. And that is the self adjusting mechanism. It keeps the cable tight on the rollers.
Ah! So it 'is' a cable-stretch compensator. It's a self-adjusting tensioner of sorts!

You can't lock it in place. It is designed that the spring gives it the desired tension, and if and when the cable loosen up in time, the spring moves the black piece out a rib, and keeps the tension.
I see. It is adjusted in one place, and then, as cable tension slackens, it's pulled out a notch, to take up the slack in the cable.

If that's the case, then pushing it in a few notches should LOOSEN the cable. Right?

Practice makes it easier...
I think I'm getting way too much practice on this BMW window regulator!

Thanks for your help. You put a lot of the puzzle together (are you an engineer?).

Here is a photo of the regulator when I pulled it out of the door.
Notice that the cable tensioner was almost all the way in at that time.
 

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#18 ·
Do a 'dry try' to assemble the whole thing but without the spring. That will make it much much easier. Then, pull the black out and hold it there with your thumb and your fist (to imitate the spring) and turn the spool with a long nose pliers, and you will see exactly how the whole thing works and a lot of questions will be answered. If not for nothing else it will help you assemble it with the spring later on. Practice makes it easier... one should hope. :)
 
#20 ·
Yes. And, empirically, I think it was much harder to pound the adjuster post inward (into the motor) than it was to simply pull it out (out of the motor).

I'm surprised by the pounding (you said malet previously). Without the spring or without tension (when the cable is loose), you should be able to push and pull the black piece by hand.

The strange thing is you'd expect the exact opposite!
That's why I called it "counter intuitive)!

That is, the spring tension is clearly placing a force on the head of the ribbed adjuster post such that there is tension pulling it OUT of the motor - yet - it seems to stay in place (probably due to the design of the white plastic 'catch' inside the white motor tube?).
It stays in place because the cable is pulled and tensioned to its limits. I think the 'catch' is there to prevent it from going IN, and loosen the tension. Think of it like the alternator or water pump belt. They want it to always be tensioned.

So, for whatever reason ... the post is not supposed to go into the motor as easily as it's supposed to be pulled out.
Right. Imagine you go on a big pothole and the shock causes the spring to compress? You don't want the cable to jump out of a roller. You want this to always be at maximum tension.

Given that pushing it in apparently decreases cable tension, that would mean that it's designed to allow an INCREASE in cable tension - but not a decrease.
Exactly.

Maybe it's a cable-stretch compensator?

Ah! So it 'is' a cable-stretch compensator. It's a self-adjusting tensioner of sorts!
:)

I see. It is adjusted in one place, and then, as cable tension slackens, it's pulled out a notch, to take up the slack in the cable.
Depends what you mean by "adjusted". By whom? If you mean by the spring - then yes. "We", can not adjust it in one place because the spring will always push it out, to the maximum tension, as determined by the spring expansion force.

If that's the case, then pushing it in a few notches should LOOSEN the cable. Right?
Yes, but the spring is going to push it right back. There's nothing you can do to loosen it. You push it in to loosen the cable just so that you can reassemble it. Then when you let go of the spring, out it goes to full tension.

I think I'm getting way too much practice on this BMW window regulator!

Thanks for your help. You put a lot of the puzzle together (are you an engineer?).

>>> Electronics, and then I worked on big military radars, so there's a lot of mechanical aspects to that too. But that was a long time ago.

Here is a photo of the regulator when I pulled it out of the door.
Notice that the cable tensioner was almost all the way in at that time.
Nice glasses.... :)
 
#21 · (Edited)
Without the spring or without tension (when the cable is loose), you should be able to push and pull the black piece by hand.
I was pounding with the mallet but at that time, the spring was still engaged - so I was fighting the spring.

I agree, it goes much more easily without the spring!

"We", can not adjust it in one place because the spring will always push it out, to the maximum tension
This is good information to get my bearings on how the thing works.

You push it in to loosen the cable just so that you can reassemble it. Then when you let go of the spring, out it goes to full tension.
In hindsight, that's what I should have done to loosen the cable tension in the first place!

BTW, in my googles, it seems the Germans use this particular type of window regulator:
- VW
- Boxter
 
#23 · (Edited)
I like the idea of working together to complete your DIY so that others benefit in the future, long after we're gone.

The great news is that we have the holy grail in hand, which is the trick to loosen & tighten the extreme cable tension, at will:

  • The ribbed stem 'is' the tension adjustment mechanism (outward=tighter)
  • The spring can potentially be wound off or on without disassembly of anything
In fact, I just now created a special tool for re-inserting the ribbed stem because it is so difficult to pound that tension adjuster inward (i.e., in order to lessen tension).

So, I'll snap pictures - but - for some reason - for the first time ever, I am no longer privileged to upload photos. I don't doubt that I post more photos than almost anyone - but - I didn't get any private messages from any moderators or system administrators (and I have email turned off) - so I'm not sure why all of a sudden, after all these years, my picture-posting privileges are missing.
 
#24 · (Edited)
No worries. We all can not upload attachment at the moment. They are upgrading our servers during the whole weekend. You missed the "Announcement" at the top of the forum. ;)

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We look forward to having this upgrades in place and providing a more speedy browsing experience.

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#25 · (Edited)
You missed the "Announcement"
Oh. Whew! I thought I was suddenly a persona non grata because I uploaded so many pictures of this endeavor.

Success at last!

In the end, it was actually trivial to re-tension my front window regulator.
I'll send the pictures of each step to MatWiz to complete his DIY ... but here is the secret.

The key to releasing tension is shown in this picture!

Without MatWiz' wizardry, I wouldn't have known to concentrate on that spring on that black post!

After focusing on the springed black ribbed tensioning rod, I was E-A-S-I-L-Y able to get the cable onto the rollers.
The extreme cable tension was no problem at all because I simply added the extreme tension as the very last step, one spring roll at a time!

I wish I had not needed to ask so many questions and to learn so much in hindsight (instead of foresight), but, here, for the next person, is the 'idealized' way to release tension:

To release tension:

  • Simply spin the large tensioning spring off (as you would a key in a keyring)
  • Each revolution of the spring will decrease the tension, until there is absolutely no tension whatsoever!
  • Once the spring is off (or nearly off) you can easily pull the (now loose) cables off the pulleys
To add tension:

  • First push the (now naked) ribbed tension rod inward (about 1/2 inch sticking out)
  • Then, string your (loose) cables around the four pulleys
  • Lastly, simply spin the large tensioning spring onto the ribbed tensioning rod (each turn adds tension!)
Voila!


I do have one question of the Wiz, though:

I'm not sure WHERE to measure from, but, the position of the two hexagonal "barrels" seems to be 'off' by about a quarter of an inch.

Q: Where do I measure from, and, should they be closer than 1/8" symmetric?

 

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#26 ·
Such an elegant solution, Bluebee! Well done! :thumbup::thumbup:

In summary, using MatWiz' wizardry and only after focusing on the black ribbed tensioning rod, I was E-A-S-I-L-Y able to get the cable onto the rollers.
The extreme cable tension was no problem at all because I simply added tension as the very last step, one spring roll at a time!

I wish I didn't have to ask so many questions and to learn so much in hindsight, but, here, for the next person, is the 'idealized' way to release tension:

To release tension:

Simply spin the large tensioning spring off (as you would a key in a keyring)
Each revolution of the spring will decrease the tension, until there is absolutely no tension whatsoever!
Then you can easily pull the (now loose) cables off the pulleys

To add tension:

First push the (now naked) ribbed tension rod inward (about 1/2 inch sticking out)
Then, string your (loose) cables around the four pulleys
Lastly, simply spin the large tensioning spring onto the ribbed tensioning rod (each turn adds tension!)
Voila!
 
#30 · (Edited)
I'm doing this for the nth time because the cable keeps jumping off the top-left corner pulley.

I think there is a need for a reverse PRE-TWIST to the cable, which, may be why it's spinning off the wheel. Still debugging. Yes. I know. (I'm slower than everyone else).

EDIT: I'm starting to damage the white plastic transmission case because of the multiple winding and unwinding of the spring catches on the edges, especially when I wind it on wrong (it goes on easily in some cases, and not in others, so I'll have to notice the difference later).

 

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#35 ·
Turn the wheel with the two ends wrapped to have about the same wraps of each side on the wheel (about two from each side?). Then insert the wheel and press to lock it in. Done. Now place the cable on the rollers if they are not already on them, and insert the spring. Finished.
 
#37 ·
Turn the wheel with the two ends wrapped to have about the same wraps of each side on the wheel (about two from each side?)
I wish when I had first taken the spool apart that I had counted the wraps - but I tried today with just two wraps on each side - and it was too loose, so it's three wraps on each side.

Now place the cable on the rollers if they are not already on them, and insert the spring. Finished.
Inserting the spring is actually easy - if you approach it from the right angle - and very difficult if you don't.

For example, today I tried to wrap the spring back on by first wrapping it around the cable outside the black post - but that turned out to be folly:

Then, I belatedly realized the right way to approach the spring wrap is to come in at a slight angle and wrap around the black post, turning the spring clockwise to wind it on.


Unfortunately, I wound and unwound that spring so many times today that I ended up damaging it a bit.
 

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#38 ·
Bad news. Today I tried another three or four times to repair the regulator. I have the wrapping and stringing down to a science, so that's not the problem.

And, I put the window clamps on the rails BEFORE mounting it in the door (which was a lesson learned).

But, still, after about five or so test traversals of the window, the wire came off the top left roller (i.e., the one that was chipped).

Given that, I'm finally convinced (by the data) that my regulator is toast - mostly due to the chip in the wheel that occurred when the regulator jammed prior to removal.
 

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#39 · (Edited)
I will search for regulator suppliers ... so ... if you have experience with particular brands and suppliers ... please let me know.

- Supplier prices lookup comparison engine (1) & BMW salvage (junkyard) parts lookup engine (1) & BMWfans search by part number (bmwfans.info parts catalog) & Realoem nominal prices by part number (1) & EACTuning actual prices by part number (1) & BMW of South Atlanta actual prices by part number (1) & Maxmillian BMW dealer prices by part number (1) & the most often recommended parts suppliers (1) & what BMW E39 parts & supplies are best to buy OEM (1) & joining BMWCCA to lower parts costs (1) (2) & what parts to always get OEM (1) which BMW dealers match prices (1) & in situ pictures of common parts of the M54 engine (1)

EDIT: Seems like the following brands are available:

  • OE 51 33 8 252 393 (Kuster is the original brand name on mine) 51338252393
  • A1 Cardone 82-2134A
  • Action Crash 1032-04050415
  • Dorman #: 740-478 or #740478
  • Hollander #: 125-58598L
  • JL Germany (Bavauto seems to sell this)
  • Partslink #: BM1350103
  • Replacement B462922 (The Parts Bin & DriveWire & auto parts warehouse seem to sell this)
  • Üro Parts 51338252393 (BMA, AutoHauzAZ, Amazon, seem to sell this)
  • VDO/Siemens (Amazon seems to sell this)
  • World Source One W0133-1601605
  • ? what others ?
Note: The driver-side front regulator seems to go by two different part numbers: OLD: 51338236859 NEW: 51338252393
Note: Part #51338252393 is for the front left, driver side; while part #51338252394 is for the front right, passenger side.
Note: E39 models built before 9/1997 apparently used a slightly different mounting method than later models do (mine is a 2002).

Note: It's interesting that Turner Motorsports has multiple items of the exact same price & brand as "The Parts Bin" (URL not provided as it is asterisked out when I type it as a single word).

Note: Here is a typical supplier's picture of the OEM brand (Kuster).

  • Notice I flipped all the pictures so as to always show the true orientation (most suppliers show it upside down)
  • Notice the white plastic take-up spool assembly is tie wrapped to the metal motor plate so I presume we need to re-use both the old motor and the five screws which held the old take-up-spool mechanism to the metal motor plate
  • We probably need to re-use the three T25 bolts at top which don't show in this picture
  • The two bottom 10mm bolts seem to come with the window regulator
  • The two window clamps seem to come with the regulator (each clamp has a T25 bolt, rubber "edge protector", T20 bolt, and the plastic window stop)
  • The regulator appears to come with the T20 bolt and clip at the center (which clips the bottom portion of the motor plate to the door)
  • The small rubber stopper on the motor plate seems to come with the regulator (this is a separate part number in realoem diagrams)
 

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#43 · (Edited)
Isn't there someone who sells (sold?) rollers replacements?
I just ran a quick search, and it's easy to find people who sell the take-up spools at prices of ***8364;7.50 for 10 pulleys (roughly about $1.25 USD or so for each pulley) but I haven't found the rollers for sale yet:



And, on Ebay, you can get single take-up spools for about five dollars:



I asked over here how moots managed to replace his roller: http://bimmerfest.com/forums/forumdisplay.php?f=103# - another window regulator question

That chipped wheel looked like that was the cause of your problem.
At this point, I can't disagree.

What happened was the window clamp jammed against the wheel, causing the chip:


EDIT:
In hindsight, the 'cheapest' ideal-DIY solution would have been:
a) Remove the tension spring (simply by spinning it off)
b) Unjam the window clamp from being stuck against the pulley (should be easy without cable tension)
c) Replace the chipped pulley (this needs some research)
d) Reassemble by spinning the tension spring back on

A quick parts search indicates the window regulator is only available as a system
It's hard to tell from the supplier descriptions and pictures, but ... the regulator seems to come with 'most' (but not all) the parts you need.

  1. The four pulleys, two cable guides & the cable & the white take-up-spool & the metal bracket seem to 'be' the window regulator:
    • The two bottom 10mm bolts seem to come with the regulator - and the T25 bolt and clip in the bottom of the metal motor bracket seems to come with the regulator - but the three top T25 bolts don't seem to come with the regulator
    • The two window clamps (and T25 & T20 bolts & rubber "#7 Edge Protector") seem to come with the regulator - as does the small rubber "#6 Absorber" in the metal bracket.
  2. As you noted, the MOTOR does not seem to be part of the standard window regulator
Reuse your old motor. It seems like that was not part of the original problem and still has service life left.
Let's hope I didn't damage it when I took the motor apart in my misguided attempt to loosen the original cable tension!


Buy the cheaper Uro window regulator from the cheapest source
I understand your logic.

Add to that the point that even the original OEM (Kuster) regulator stinks, and, I wonder how bad the aftermarket brands can be, given the OEM is lousy to start with. Plus, I hate to reward either BMW or the OEM manufacturer - they should be punished instead.

Years ago, when I did mine, there was a guy who machine made aluminum roller replacements and sold them privately
I wonder how one would re-mount a pulley, once removed?

Searching, I find this Bimmerfest OP didn't elaborate on how he removed his pulley, but clearly you can see it removed in his picture (I circled the parts in red).


Here's a closeup of the rivet, pulley, and mounting hole from the photo above:


I would buy the least expensive replacement and install it.
So far, the cheapest I can find for new parts is about $44 for the regulator and about $35 for the motor (plus about 10% CA tax & shipping, if applicable).

At least you learned a lot. Now we can brag that we are the only two people on the face of the planet who know how to DIY reassemble that thing.
Without you and your astute insistence that I focus on the spring being THE tension mechanism, I would never have been able to figure out how to loosen and reapply tension so effortlessly!

In fact, before I found your 2007 DIY for the take-up spool, I had already removed the motor because the window clamp had jammed against the upper pulley (causing the chip). The prior mistake there was that I had removed the window, and then, at some point, accidentally hit the "up" switch on the powerful window motor. I shouldn't have done that! Lesson learned: Don't remove the window - and - if you do - don't hit the UP switch! (The number of mistakes I made in this repair, so far, are astounding!)

Of course, removing the motor and spinning it by hand, would have been the right thing to do to unjam the clamp from the upper pulley ... if that was the only problem - but the jam chipped the pulley - which became the real problem at hand.
 

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#41 ·
BB:
I agree with your assessment regarding possible reuse of your regulator. That chipped wheel looked like that was the cause of your problem. Since I have not done this repair, I have no firsthand experience regarding these specific parts. I can't imagine anyone selling just the roller wheel. The window regulator appears to be a fairly complex system with multiple components involved. A quick parts search indicates the window regulator is only available as a system. This is what I would recommend:

1. Reuse your old motor. It seems like that was not part of the original problem and still has service life left. The cost of replacement makes it not worth replacing at this point. If it breaks in the future, you have the skills to replace it. And since it doen't provide a critical function, it does not require preepmtive replacement, unlike the cooling system.

2. You clearly should replace the entire window regulator system. This will also eliminate any concerns over some of the system components (cable, spring, etc.) you may have abused during this repair. Buy the cheaper Uro window regulator from the cheapest source as it is nearly half the price of OE. Given the age and mileage on your car, it will likely last the remaining lifetime of the car. Even if it fails, and you must replace it again, you're about even in net cost (since this is a DIY).

My rationale is that the window regulator has no performance or driving related impact other than making your window go up or down. Hence, it does not deserve getting the premium OE parts, like for your engine or suspension. By now, you are an "expert" at this repair. Hence, doing it again would be relatively easy (but still a PITA). So labor is not a cost concern. At the end, the net cost is about $60 and your labor (which was considerable). But since you have added to our collective knowledge on this issue, the ROI of you investment will be high. So thanx for documenting your experience.
 
#42 ·
....
I can't imagine anyone selling just the roller wheel. The window regulator appears to be a fairly complex system with multiple components involved. A quick parts search indicates the window regulator is only available as a system.
Years ago, when I did mine, there was a guy who machine made aluminum roller replacements and sold them privately. To my best recollection.

But then at that time we didn't have such a large variety of sources to buy regulators from. And the price was high. I think it was over $180 for the regulator, without the motor.

Looking at these prices, I wouldn't even bother and I can see why this guy would not even make those any more. I would buy the least expensive replacement and install it. Keep the old one just in case you'd need parts in the future.

Al least you learned a lot. Now we can brag that we are the only two people on the face of the planet who know how to DIY reassemble that thing. :bigpimp:
 
#44 · (Edited)

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#45 · (Edited)
Just for the record, I finally gave up (I should have given up sooner) and bought the least expensive window regulator I could find (it was about $50 plus shipping).

I was worried it might not fit - but - upon close inspection, it seems to be an EXACT replacement. Here are some pictures to show what it looks like.



About the only difference was that the new regulator used hex and Phillips head bolts instead of Torx bolts.


One idea I noticed was that we can grease the existing window regulators when we work on them by shoving grease into this hole in the back of the winding spool.


It's interesting to note that the new regulator came with the two cable ends asymmetrically wrapped in the spool such that the window clamps were near the BOTTOM of the rails instead of in the middle where I expected them to be were the wires wrapped symmetrically.


I was also surprised at the amount of grease inside the take up spool.


The transmission case was tie wrapped to the motor bracket so I had to transfer over my old motor and five T20 screws.


Interestingly, the new regulator came with the bottom 10mm hex-head bolts and the T25 Torx clip for the motor plate connection to the door frame - but the new window regulator did NOT come with the three T20 bolts for the top connection (nor the five T20 screws holding the motor on).


But, other than the different bolts used in the clamp itself, the $50 window regulator appeared identical to the original window regulator.


The one lesson to take from this is to note how they wound the spool ...

So that the clamps would be at the BOTTOM (instead of in the middle):
 

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#46 · (Edited)
I don't know how I made this sophomoric mistake, but, in putting it all back together, I must have adjusted the stops on the rear clamp wrong - such that the window now doesn't go down all the way in the back half.

I'm really tired of working on this door and don't want to open it all up again.

Do you think this dumb mistake will cause any problems if I just leave it be?


EDIT:
I opened this thread in the hopes of finding out HOW to properly adjust the window glass before buttoning it all up!
- Do we have a step-by-step DIY for ADJUSTING window glass when replacing the regulator?
http://youtu.be/RP-2wQx6Wfs
 

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