Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > X Series > X3 E83 (2004 - 2010)

X3 E83 (2004 - 2010)
Talk about the E83 BMW X3 in this forum!

Reply
 
Thread Tools Display Modes
  #1  
Old 09-07-2011, 11:31 AM
pburnett pburnett is offline
Registered User
Location: Severna Park, MD
 
Join Date: Jan 2011
Posts: 30
Mein Auto: 2006 BMW X3, Lexus IS300
Transfer Case Actuator potential free fix!

A couple weeks ago, I got the "terrible triad" of lights (ABS, 4x4, and Brake). Recently, I got the clicking noise after turning the car off and was able to determine that it was coming from a transfer case. Using several posts from here, especially this one:

http://www.bimmerfest.com/forums/sho...6&postcount=19

I bought a new transfer case actuator and installed it. Problem solved, no lights, no clicking, all better. It is not a cheap part at 720 bucks from getbmwparts.com, and 900 bucks elsewhere, so the engineer in me wanted to figure out why they were failing.

Which brings me to the purpose of this post. I disected the old actuator to find out what the heck is going on inside it. I appologize for the huge pictures, but some sort of resolution was needed to describe what I was trying to say.

What the actuator looks like when off the car:


And broken down into the pieces: Bottom right is the motor, top right is the brush assembly, top left is a guard of some sort that pops off (albeit bent and unusable once you have it off) and the bottom left is the gear assembly (we'll focus on this one)


After I popped off the oil guard piece, here is what the inside looked like, a ton of shavings and grease.


and closer:



So you can see the motor turns a worm gear which is mated to a black gear (which is made of plastic !!!) Eventually, this gear wears down like crazy and doesnt have any teeth left to grip the worm gear. This is what causes the slipping, and the error lights, and especially the clicking sound.

In this photo, you can see the change from good gear area to the bad area. The good area is on the left, and as you follow the black gear around to the right, you can see where it has been worn down from sitting all the time.




So, I went farther. I took off the black gear to see what it looked like:
Good side (what it should look like everywhere):


Bad side (Cause of the problem)


POTENTIAL SOLUTION:

So now we know what the cause is, how can we fix it? It has been (from my research) that everyone just buys a new actuator. Yes, it fixes the problem, I can vouch for that, but I don't know how many other people looked into what CAUSED the problem.

I bet you could unbolt the motor from the gear housing assembly (it is held on by 4 torx bolts that come off quite easily compared to trying to remove the actuator from the car).
Mark a location of the current position on the white plastic gear you can see in the first photo. After the motor is unbolted and removed (ONLY THE MOTOR, DONT DESTROY YOUR ACTUATOR AND TAKE THE WHOLE THING APART!!!!), turn the white plastic gear 180 degrees from its current location. This takes the bad part of the gear and puts it where it will not get used, which means that a good part is now in contact with the worm gear.

Re-insert the motor and bolt back together. This should give you, say another 65k miles (when mine failed) or so before you likely have to replace the actuator. Re-install on your transfer case, and voila! you should be good to go with only an hour or so of your time wasted instead of time and 900 bucks.

I haven't tried this, so try it at your own risk, but with pulling everything apart, it seems like a pretty safe bet, but obviously I can't be held responsible if something does go wrong.

Hope perhaps it can save someone almost a thousand dollars. I believe my logic is sound, but I look forward to your comments!
Reply With Quote
Advertisement
  #2  
Old 09-07-2011, 12:07 PM
spokelizard spokelizard is online now
Officially Welcomed to the 'Fest
Location: SF Bay Area
 
Join Date: Jun 2009
Posts: 757
Mein Auto: 2007 X3 MT
Brilliant!

Great idea, great documentation. Hope I never have to do this, but I'll definitely keep it in my arsenal.

Another BMW plastic part causes major problems. You didn't say, but I assume that the little plastic gear can't be purchased as a separate part.
Reply With Quote
  #3  
Old 09-07-2011, 12:40 PM
bluskye bluskye is offline
Officially Welcomed to the 'Fest
Location: chicago
 
Join Date: Jul 2002
Posts: 786
Mein Auto: 2006 330i / 2007 X3
Was the actuator difficult to replace? Do you have a DIY?
Reply With Quote
  #4  
Old 09-07-2011, 02:02 PM
timfitz63's Avatar
timfitz63 timfitz63 is offline
MT = Doppler Shifting
Location: Lorena & San Antonio, TX
 
Join Date: Aug 2010
Posts: 860
Mein Auto: 2007 X3 (MT)
OK. Engineer here. Not quite following your description of the gear reversal and how that 'fixes' the problem, so maybe I'm missing something critical, but:

I don't think reversing (or simply rotating, if that's what you're suggesting) the exposed white gear 180 degrees will correct the problem. Yes, that could re-position a 'good' portion of the black gear onto the worm gear, but regardless of how the gears are positioned, as all of them turn, the black gear will rotate until its worn portion reaches the worm gear, then it stops turning again. This will happen within one rotation of the black gear.

Based on the wear that you highlighted on the black gear, I think it would have to be replaced -- if one can find the part...
__________________

X3 w/6-speed & Sport Package:
A sports sedan disguised as an SUV...
Reply With Quote
  #5  
Old 09-07-2011, 02:16 PM
pburnett pburnett is offline
Registered User
Location: Severna Park, MD
 
Join Date: Jan 2011
Posts: 30
Mein Auto: 2006 BMW X3, Lexus IS300
Quote:
Originally Posted by timfitz63 View Post
OK. Engineer here. Not quite following your description of the gear reversal and how that 'fixes' the problem, so maybe I'm missing something critical, but:

I don't think reversing (or simply rotating, if that's what you're suggesting) the exposed white gear 180 degrees will correct the problem. Yes, that could re-position a 'good' portion of the black gear onto the worm gear, but regardless of how the gears are positioned, as all of them turn, the black gear will rotate until its worn portion reaches the worm gear, then it stops turning again. This will happen within one rotation of the black gear.

Based on the wear that you highlighted on the black gear, I think it would have to be replaced -- if one can find the part...
It looked to me that the black gear doesn't turn the whole way around, only really over that worn area. I believe BMW used a full gear as to ease the installation (not having to worry about the position you put it in)

If it continuously rotated around, woundn't the gear wear more evenly and not in a single spot about the length of the worm gear?

Again, I guess it might not be a fix per say, but it could seriously delay the need to spend 900 bucks.

Just a thought.

Last edited by pburnett; 09-07-2011 at 02:17 PM.
Reply With Quote
  #6  
Old 09-07-2011, 02:19 PM
pburnett pburnett is offline
Registered User
Location: Severna Park, MD
 
Join Date: Jan 2011
Posts: 30
Mein Auto: 2006 BMW X3, Lexus IS300
Quote:
Originally Posted by bluskye View Post
Was the actuator difficult to replace? Do you have a DIY?
It wasn't too bad. You need external torx sockets, but after I got that, it wasn't bad. I'll try and post the DIY someone else wrote that I followed with some of my own notes.
Reply With Quote
  #7  
Old 09-07-2011, 02:45 PM
timfitz63's Avatar
timfitz63 timfitz63 is offline
MT = Doppler Shifting
Location: Lorena & San Antonio, TX
 
Join Date: Aug 2010
Posts: 860
Mein Auto: 2007 X3 (MT)
Quote:
Originally Posted by pburnett View Post
It looked to me that the black gear doesn't turn the whole way around, only really over that worn area. I believe BMW used a full gear as to ease the installation (not having to worry about the position you put it in)...
Maybe I need to fiddle with it myself, like you have, to really see what's going on there. But what you're describing wouldn't be consistent with how a worm gear and a cog gear typically interact.

Quote:
Originally Posted by pburnett View Post
... If it continuously rotated around, woundn't the gear wear more evenly and not in a single spot about the length of the worm gear...?
It may have worn evenly until it failed; you'd have to compare the teeth on the gear you extracted from your actuator to a brand new gear.

But I think what's happening is that these plastic gears are not durable enough; they either have a weak spot or just get 'chewed up' by the metal worm gear over time. I'm actually rather shocked that BMW even used plastic cogs inside a transfer case, but...

All is not lost, though; you did a good job in isolating the weak component in the actuator! Hopefully someone can zero in on a supplier for those black gears (they've gotta come from somewhere...), and we can all re-build our failed xDrive actuators!
__________________

X3 w/6-speed & Sport Package:
A sports sedan disguised as an SUV...
Reply With Quote
  #8  
Old 09-07-2011, 03:16 PM
Supercourse Supercourse is online now
Officially Welcomed to the 'Fest
Location: British Columbia, Canada
 
Join Date: Feb 2008
Posts: 3,149
Mein Auto: 2004 X3 2.5i
Quote:
Originally Posted by timfitz63 View Post

But I think what's happening is that these plastic gears are not durable enough; they either have a weak spot or just get 'chewed up' by the metal worm gear over time. I'm actually rather shocked that BMW even used plastic cogs inside a transfer case, but...
I was surprised that even garage door opener motors have those nylon worm drive gears.

Recently took apart one - same sort of thing. The plastic just gets badly chewed up in one section.

The repair guy said it happens randomly, through bad luck.
They otherwise work fine for well over 10 years.

As you say, a weak point in the plastic, or maybe things get slightly out of alignment and the damage is started.

May be the same for the transfer case actuator - some will have that problem, but not inevitable.
Reply With Quote
  #9  
Old 09-07-2011, 03:57 PM
pburnett pburnett is offline
Registered User
Location: Severna Park, MD
 
Join Date: Jan 2011
Posts: 30
Mein Auto: 2006 BMW X3, Lexus IS300
Quote:
Originally Posted by timfitz63 View Post
Maybe I need to fiddle with it myself, like you have, to really see what's going on there. But what you're describing wouldn't be consistent with how a worm gear and a cog gear typically interact.
I see what you are saying. I figured that the gear had, say, 90 degrees of freedom in rotation (on/off on either side of the 90) for actuated/non-actuated. So the real question when the actuator is active, does it spin the black gear constantly or does it stop at some point? I have no idea. Really, it is because I don't know what or how the inside of the X3 transfer case works or looks like, but I am beginning to think you may be correct. Unfortunatly, I don't see a way to get to the black gear without doing some serious damage to the cover that I pulled off, so even if you had found a replacement, I don't think you can get to it to just replace it, but maybe with some luck you can.

Just for reference, I attached kind of what I was talking about in the picture. I'm just wondering if maybe the motor goes forward/reverse to turn on and off something with the transfer case. something like this would cause only this area to be used. Not the best solution for it, but likely cheap and easy to manufacture.
Attached Thumbnails
Click image for larger version

Name:	Untitled.png
Views:	608
Size:	6.0 KB
ID:	292056  
Reply With Quote
  #10  
Old 09-07-2011, 08:09 PM
X3-terrestrial's Avatar
X3-terrestrial X3-terrestrial is offline
Aficionado
Location: N.Miss - Memphis,TN Area
 
Join Date: Aug 2008
Posts: 2,631
Mein Auto: '05 X3, '95 M3, '89 MkI
Quote:
Originally Posted by pburnett View Post
I see what you are saying. I figured that the gear had, say, 90 degrees of freedom in rotation (on/off on either side of the 90) for actuated/non-actuated. So the real question when the actuator is active, does it spin the black gear constantly or does it stop at some point? I have no idea. Really, it is because I don't know what or how the inside of the X3 transfer case works or looks like, but I am beginning to think you may be correct. Unfortunatly, I don't see a way to get to the black gear without doing some serious damage to the cover that I pulled off, so even if you had found a replacement, I don't think you can get to it to just replace it, but maybe with some luck you can.

Just for reference, I attached kind of what I was talking about in the picture. I'm just wondering if maybe the motor goes forward/reverse to turn on and off something with the transfer case. something like this would cause only this area to be used. Not the best solution for it, but likely cheap and easy to manufacture.
Your theory makes sense to me, mostly since Xdrive is RWD most of the time. And it transfers power to the front as needed, it seems like the electric motor turns more the gear, as more power is transferred to the front, wearing the "most used" area considerable more.
Reply With Quote
  #11  
Old 09-08-2011, 05:28 AM
timarnold timarnold is offline
TA
Location: Maryland
 
Join Date: Sep 2009
Posts: 542
Mein Auto: 2003 bmw 525i
What I think you are looking at in the top picture, top right hand side is a brushless DC motor, which would be controlled by output from a computer that would tell it to turn a certain number of revolutions in a specific direction. It is likely that the drive gear never does rotate 180, so rotating the drive gear may work.

The concern would be why the gear wore out. It is obviously being overloaded, which could either be a processing problem in molding the gear or it could be that whatever the actuator is trying to turn is not turning a freely as it is supposed to.

At any rate, it would definitely be worth a try. The only downside I see is expending the time to remove the actuator.
Reply With Quote
  #12  
Old 09-08-2011, 07:45 AM
Supercourse Supercourse is online now
Officially Welcomed to the 'Fest
Location: British Columbia, Canada
 
Join Date: Feb 2008
Posts: 3,149
Mein Auto: 2004 X3 2.5i
Quote:
Originally Posted by X3-terrestrial View Post
..... mostly since Xdrive is RWD most of the time.
I thought when xDrive has been discussed before, BMW's explanation is that it is only pure RWD under very limited circumstances (such as when parking, ABS activated, over 112 m.p.h.).

Under most conditions, it's a 40/60 split.

See:
http://www.bimmerfest.com/forums/sho...d.php?t=427207

The xDrive PDF referenced does attempt to explain how the servo motor on the transfer case works to actuate the clutch packs in the transfer case.
Reply With Quote
  #13  
Old 09-08-2011, 09:19 AM
X3-terrestrial's Avatar
X3-terrestrial X3-terrestrial is offline
Aficionado
Location: N.Miss - Memphis,TN Area
 
Join Date: Aug 2008
Posts: 2,631
Mein Auto: '05 X3, '95 M3, '89 MkI
Quote:
Originally Posted by Supercourse View Post
I thought when xDrive has been discussed before, BMW's explanation is that it is only pure RWD under very limited circumstances (such as when parking, ABS activated, over 112 m.p.h.).

Under most conditions, it's a 40/60 split.

See:
http://www.bimmerfest.com/forums/sho...d.php?t=427207

The xDrive PDF referenced does attempt to explain how the servo motor on the transfer case works to actuate the clutch packs in the transfer case.
Yes, I meant to say rear-bias. Basically what this actuator does is to tell the TC how much torque to pass onto the front wheels. So the theory that doesn't turn 360* sounds right.

Or maybe it *could* turn more but only on cases when full traction is needed to the front wheels which will depend on the individual driving conditions. Maybe this "spot" is the one that gets more use, therefore wearing out faster.

It would be nice if they'd sold an "Actuator Rebuilding kit" instead of selling the whole unit as a replacement.
Reply With Quote
  #14  
Old 09-08-2011, 02:46 PM
timfitz63's Avatar
timfitz63 timfitz63 is offline
MT = Doppler Shifting
Location: Lorena & San Antonio, TX
 
Join Date: Aug 2010
Posts: 860
Mein Auto: 2007 X3 (MT)
Quote:
Originally Posted by pburnett View Post
I see what you are saying. I figured that the gear had, say, 90 degrees of freedom in rotation (on/off on either side of the 90) for actuated/non-actuated. So the real question when the actuator is active, does it spin the black gear constantly or does it stop at some point? I have no idea. Really, it is because I don't know what or how the inside of the X3 transfer case works or looks like, but I am beginning to think you may be correct. Unfortunatly, I don't see a way to get to the black gear without doing some serious damage to the cover that I pulled off, so even if you had found a replacement, I don't think you can get to it to just replace it, but maybe with some luck you can.

Just for reference, I attached kind of what I was talking about in the picture. I'm just wondering if maybe the motor goes forward/reverse to turn on and off something with the transfer case. something like this would cause only this area to be used. Not the best solution for it, but likely cheap and easy to manufacture.
OK, I follow what you're saying now too.

Well, if the black gear only turns a quarter-turn or so at most, your idea could potentially work; how far the black gear rotates is going to depend on the reduction between it and the worm gear, and how much the black gear needs to turn in order to adjust the torque transfer between the axles...
__________________

X3 w/6-speed & Sport Package:
A sports sedan disguised as an SUV...
Reply With Quote
  #15  
Old 09-08-2011, 02:51 PM
pburnett pburnett is offline
Registered User
Location: Severna Park, MD
 
Join Date: Jan 2011
Posts: 30
Mein Auto: 2006 BMW X3, Lexus IS300
Quote:
Originally Posted by timfitz63 View Post
OK, I follow what you're saying now too.

Well, if the black gear only turns a quarter-turn or so at most, your idea could potentially work; how far the black gear rotates is going to depend on the reduction between it and the worm gear, and how much the black gear needs to turn in order to adjust the torque transfer between the axles...
Yup.... And thats a big IF, and I don't know the answer. But if someone has this problem and gives it a try, we may find out more.
Reply With Quote
  #16  
Old 09-08-2011, 02:55 PM
timfitz63's Avatar
timfitz63 timfitz63 is offline
MT = Doppler Shifting
Location: Lorena & San Antonio, TX
 
Join Date: Aug 2010
Posts: 860
Mein Auto: 2007 X3 (MT)
Quote:
Originally Posted by pburnett View Post
Yup.... And thats a big IF, and I don't know the answer...
Yeah, I couldn't seem to cobble together the proper string of keywords to 'google' a description or working schematic of the X3's transfer case, so I can't answer the question either...
__________________

X3 w/6-speed & Sport Package:
A sports sedan disguised as an SUV...
Reply With Quote
  #17  
Old 09-12-2011, 04:56 PM
dannyy06 dannyy06 is offline
Registered User
Location: Puerto rico
 
Join Date: Dec 2009
Posts: 21
Mein Auto: Bmw X3
Transfer case actuator

I just took out the actuator and its just like in the first picture
before i buy it have anyone try to fix it like its explain in this post

i willing to try but how can i put the worm in without messing up the the gear
Reply With Quote
  #18  
Old 09-12-2011, 05:34 PM
pburnett pburnett is offline
Registered User
Location: Severna Park, MD
 
Join Date: Jan 2011
Posts: 30
Mein Auto: 2006 BMW X3, Lexus IS300
no one has tried it, you would be thre first one!

I'm really curious as to if it would work. It might, it might not. Do you have the clicking noise when you turn off the car from underneath?

To do the "fix", all you have to do is unbolt the actuator motor (I think you said you did this already), turn the white gear 180 degrees, and put the motor back in. The worm gear will seat itself properly (I have tried this with my messed up one, so you should have nothing to worry about). Reinstall and then let us know!

If you can drive a few times and try to push the X-drive system so that it has to work, and report back many of us would be very eager to hear how it works. Good luck!
Reply With Quote
  #19  
Old 09-13-2011, 01:42 PM
dannyy06 dannyy06 is offline
Registered User
Location: Puerto rico
 
Join Date: Dec 2009
Posts: 21
Mein Auto: Bmw X3
Already done!!!!!!!!!

IT WORKS..........

been driving the whole day without any problem and without the lights coming back on
and no clicking sound when turning the engine off.

Thanks for the help this was a successful experiment that save me lot of $$$$$$$$
Reply With Quote
  #20  
Old 09-13-2011, 01:47 PM
pburnett pburnett is offline
Registered User
Location: Severna Park, MD
 
Join Date: Jan 2011
Posts: 30
Mein Auto: 2006 BMW X3, Lexus IS300
Quote:
Originally Posted by dannyy06 View Post
Already done!!!!!!!!!

IT WORKS..........

been driving the whole day without any problem and without the lights coming back on
and no clicking sound when turning the engine off.

Thanks for the help this was a successful experiment that save me lot of $$$$$$$$
HECK YES!!!!!! too bad it cost me to find out, be it sounds like we have a fix that will delay the need to change the whole assembly.
Reply With Quote
  #21  
Old 09-13-2011, 01:52 PM
dannyy06 dannyy06 is offline
Registered User
Location: Puerto rico
 
Join Date: Dec 2009
Posts: 21
Mein Auto: Bmw X3
Eventually a new one its going to be needed but my has 66000 miles, lets hope that it last another 66000 .......

thanks again.
Reply With Quote
  #22  
Old 09-13-2011, 02:03 PM
crenninger crenninger is offline
Registered User
Location: Redwood City - CA
 
Join Date: Aug 2011
Posts: 59
Mein Auto: '04 X3 3.0i
maybe when doing the 180 turn, do a little less, then you can do it twice... like turn only 1/3 it doesn't look like the engagement is using more than a 1/3 turn.

Also while in there, why not adding some grease to reduce friction and thus lifetime?
Reply With Quote
  #23  
Old 09-13-2011, 02:10 PM
pburnett pburnett is offline
Registered User
Location: Severna Park, MD
 
Join Date: Jan 2011
Posts: 30
Mein Auto: 2006 BMW X3, Lexus IS300
I see good logic in both of those. It will be interesting to see if more people can have success with this. Either way, I would mark the bad area somehow so you know which way you turned it. I could see 1/3 turn working, but I wouldn't go much less than that.
Reply With Quote
  #24  
Old 09-13-2011, 02:14 PM
timfitz63's Avatar
timfitz63 timfitz63 is offline
MT = Doppler Shifting
Location: Lorena & San Antonio, TX
 
Join Date: Aug 2010
Posts: 860
Mein Auto: 2007 X3 (MT)
Quote:
Originally Posted by dannyy06 View Post
Already done!!!!!!!!!

IT WORKS..........

been driving the whole day without any problem and without the lights coming back on
and no clicking sound when turning the engine off.

Thanks for the help this was a successful experiment that save me lot of $$$$$$$$
Well, sorry to rain on the parade, but don't celebrate just yet...

Are you certain that you fully exercised the xDrive so that the full range of torque transfer was explored? If not, you might discover that the black gear will end up slipping at some stage -- like during inclement weather...

I recommend cautious optimism. Hopefully "pburnett's" idea will stand the test of time, but let's see how your system handles this 'shade tree repair' as winter sets in... Honestly, I hope it bears itself out successfully!
__________________

X3 w/6-speed & Sport Package:
A sports sedan disguised as an SUV...
Reply With Quote
  #25  
Old 09-13-2011, 02:20 PM
pburnett pburnett is offline
Registered User
Location: Severna Park, MD
 
Join Date: Jan 2011
Posts: 30
Mein Auto: 2006 BMW X3, Lexus IS300
Quote:
Originally Posted by timfitz63 View Post
Well, sorry to rain on the parade, but don't celebrate just yet...

Are you certain that you fully exercised the xDrive so that the full range of torque transfer was explored? If not, you might discover that the black gear will end up slipping at some stage -- like during inclement weather...

I recommend cautious optimism. Hopefully "pburnett's" idea will stand the test of time, but let's see how your system handles this 'shade tree repair' as winter sets in... Honestly, I hope it bears itself out successfully!

I agree 100%. I'm optimistic now, but the true test would be winter, and unfortunatly, as the poster who did the fix is in Puerto Rico, we may not see it. I recommend finding some loose dirt or gravel roads and make the xDrive work. Then, we will see if it truely is possible to delay buying a new actuator.
Reply With Quote
Reply

Bookmarks


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > X Series > X3 E83 (2004 - 2010)
Today's Posts Search
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On



Forum Jump


All times are GMT -7. The time now is 10:49 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
© 2001-2011 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms