[Fudman]

A few weeks ago, I posted this question about overfilling ATF here: http://www.bimmerfest.com/forums/showthread.php?t=587189&highlight=overfilling+atf
After reading the responses, I wasn't too worried but still did not feel entirely comfortable as the car sounded different as well as drove a little different (better). So I contacted gtxragtop (Dave) to see what he thought as he has done a lot of research on these ZF trannys. He cautioned about overfilling. So I decided to do another drain. I put the car up and drained per the instructions. I had the car tilted about 1" higher in the rear when measuring at the jackpoints, based on Dave's previous experience (he used a 2" tilt). Like him, I'd rather fill a little higher than lower. I was a little more than a pint high. So no big deal, I capped it up and went for a test drive. The car is noticeably quieter. The shifts are every bit as smooth but the car is somehow quieter. I have no clue why but now I am wondering if I possibly did any damage while driving with excess ATF (about 1,500 miles, mostly highway) :dunno:. Anyway, just wanted to let folks know that if their engine/tranny sounds louder after an ATF drain & fill, it is likely you are running a little high and you should drain some off.

 

[champaign777]

how much difference we are talking about ?
per my understanding it was something like 100-200 ML no ? or it was 0.5L ??
again i doubt you will feel any difference with +/- 100-200 ML
i drained 5.8L and i filled back 6L , that's it , 0 difference before and after

these numbers make all difference and only you know the real story

 

[Fudman]

It was over a pint which was probably a little over 500 ml. But the audible difference is very noticeable. Something I would not expect nor can I explain. :dunno:

 

[bmw_n00b13]

a US pint is 473mL. They rip us off with their mini-cans of beer!

Overfilling isn't a good idea, with a manual, diff, or engine you'll get it foaming, with an auto, I don't know what will happen but it can't be good.Better over than under but no reason to go out of your way to fill over, IMHO.

 

[Jason5driver]

I think you are fine.
But, I am no expert.
IMO, I would still make sure the car is level when filling, as is outlined in the Bentley manual.
What fluid did you use?

And do remember something from Rf900 about it being OK to overfill a wee bit....
I will have to find it...
Thanks!
Jason

 

[rdl]

A few weeks ago, I posted this question about overfilling ATF here: http://www.bimmerfest.com/forums/showthread.php?t=587189&highlight=overfilling+atf

... stuff deleted ...

I had the car tilted about 1" higher in the rear when measuring at the jackpoints, based on Dave's previous experience (he used a 2" tilt). Like him, I'd rather fill a little higher than lower. I was a little more than a pint high.

... stuff deleted ...

I got curious about jack pad height in this thread.
TIS says "Vehicle must be horizontal" with no elaboration. So the $64,000 question is, how does one make the car level? What loading, if any, does BMW expect when filling transmission. And does suspension "age droop," tire deflection, gas tank full, etc. matter.

So I went and measured my car: '03 530i, std suspension, stock size 225/55 16 tires, 29 psi front, 33 psi rear, no weights, 90k miles on springs and 1/2 tank of gas.

Measured from the floor, the rear jack pad is 17 mm or 3/4" higher than front.

Then for some corrections based on actual vs. spec ride height, which assumes weighting.
Measured ride height two ways: to bottom of rim, then to floor. Since we're interested only in differences of measured vs. spec, not the actual values, the result should be the same except for tire deflection (assuming front & rear tires are same size)
Front to rear ride heights delta was 7 mm based on measuring to the bottom flange of the rim, per TIS. Using floor based measurements, 15 mm.
Converted all the distances to angles & calculated back to a corrected height difference between front and rear jack pads.
Results for difference (rear higher than front) in jack pad height were:
1 "should be" using rim based ride height => 14 mm or 9/16"
2 "should be" using floor based ride height => 10mm or 3/8"

So, tire pressures can make a small difference if you fill the tranny over a pit or on a drive-on rack.
If placing the car on jack stands, something around 1/2" to 3/4" higher at rear jack pad would be close.

Now for the joker.
Concrete floors are sloped between 1% and 2% for drainage. Over the span between jack pads this means a drop from level of 15 - 30 mm or 5/8" to 1 1/4". For the wheelbase span, 28 - 56mm or 1 1/8" to 2 1/4". One would have to correct for this too, in order to get the car level.

Well, I sure don't like where this has led. It looks as though one needs a calculator and a laser level or surveyor's transit before starting on a tranny fill!
:rofl:

 

[microswitch]

The old adage " Splitting hairs" come to mind.
There is so much information in here and everywhere also about ATF to make you really do nothing, (Unless you have a death wish).
Change the lifetime fluid or not?
Change before 100K? after 100K? don't change it at all?
Do not change if over 100K or else you will blow up the tranny ?
Don't ever overfill or else?
If you fill make sure you are level
Better yet maybe 1" more up in the back or
2% on a slab concrete ?
WTF??
I have maintained my car the best I can, Did all there was to do, now I'm concern about changing the ATF, but wait I have 104K !! I can not change it anymore.. so BMW screwed me telling me NOT to change the ATF ? I purchased my car with 26K . Bought the extended maintenance with BMW and done all they said I had to do till 80K when my extension ran out.
Then I did the CVV, ABS module, then Cooling Over All , then the vanos. the OFH gasket the valve cover gasket, the twisted seat, the pixel on the MID, planning on doing the suspension..
Now if I do my ATF at 104k I may blow the tranny.....
I can't win can't I ?

 

[Jason5driver]

The old adage " Splitting hairs" come to mind.
There is so much information in here and everywhere also about ATF to make you really do nothing, (Unless you have a death wish).
Change the lifetime fluid or not?
Change before 100K? after 100K? don't change it at all?
Do not change if over 100K or else you will blow up the tranny ?
Don't ever overfill or else?
If you fill make sure you are level
Better yet maybe 1" more up in the back or
2% on a slab concrete ?
WTF??
I have maintained my car the best I can, Did all there was to do, now I'm concern about changing the ATF, but wait I have 104K !! I can not change it anymore.. so BMW screwed me telling me NOT to change the ATF ? I purchased my car with 26K . Bought the extended maintenance with BMW and done all they said I had to do till 80K when my extension ran out.
Then I did the CVV, ABS module, then Cooling Over All , then the vanos. the OFH gasket the valve cover gasket, the twisted seat, the pixel on the MID, planning on doing the suspension..
Now if I do my ATF at 104k I may blow the tranny.....
I can't win can't I ?

IMO, you would be fine replacing the ATF at the mileage, but the decision is up to you...

 

[bmw_n00b13]

BMW fills the fluid on a standard 4 point hoist. The arms are equal heights, and level. Therefore the car, as measured between jackpoints, is level. That's what they mean. You don't fill tranny fluid with the car on the ground! I'm skinny and can fit mostly under the car when it's not jacked up, but how exactly do you fill it with the engine running without having a death wish?!

ZF recommends changing the fluid at 100k miles, then 30k thereafter. I suspect this is to prevent conflict with BMW's warranty, as BMW considers lifetime to be the life of an extended warranty, so what they really mean is "every 30k, but we don't want to get in an argument with BMW's lawyers"

 

[Fudman]

Measured from the floor, the rear jack pad is 17 mm or 3/4" higher than front.

This issue of what is level is a good question. My rear pad is also higher than my front. I simply added an inch to the rear when I jacked the car up. Hence, the net difference was about 1.5".

What fluid did you use?

I used Castrol Import Multi-vehicle ATF. It's ESSO LT 71441 compatible.

 

[rdl]

BMW fills the fluid on a standard 4 point hoist. The arms are equal heights, and level. Therefore the car, as measured between jackpoints, is level. That's what they mean. You don't fill tranny fluid with the car on the ground! I'm skinny and can fit mostly under the car when it's not jacked up, but how exactly do you fill it with the engine running without having a death wish?!

ZF recommends changing the fluid at 100k miles, then 30k thereafter. I suspect this is to prevent conflict with BMW's warranty, as BMW considers lifetime to be the life of an extended warranty, so what they really mean is "every 30k, but we don't want to get in an argument with BMW's lawyers"

I agree with all the posts above pointing out that we are getting into a lot of conflicting opinions (many unsupported by facts) & many gritty details here. Even past the point of exhaustion and paralysis for many. But difficult does not mean unimportant.

I was stuck by Fudman's report above that a 1/2 litre of overfill (of a 9 or 10 litre total) made a difference to the way his transmission was behaving. Fudman has always beens a reliable, objective reporter in my experience, so I paid attention. It makes me wonder if reports of transmission failure soon after a drain and fill are related to inadvertent under or overfills because the car was not "BMW level", whatever that is.

I do expect that dealers follow the TIS procedure while using a 4 arm hoist on the jack pads or a drive-on hoist or repair pit whatever they have. And that the equipment has been leveled. In my experience (not at BMW dealerships) some are, some are not. But this doesn't mean it is a robust process, especially since TIS does not define how to determine a level car. The dealers are probably as much in the dark as we are and simply do what they can with what they have.

I've seen many posts reporting BMW's new 100k mile (160k km) fluid change recommendation. And then my local dealer told me with great certainty 265k km, which is supiciously close to 160/0.62 which is the conversion from miles to km applied again. WFT!! And to top it off, the ZF document attached on page 3 says 80k km to 120k km or 8 years. Double WTF.

I don't recall seeing the 30k mile change interval on subsequent changes. Can someone post the document from ZF or BMW for that guideline?

Meantime, I'm in ZF's range for a drain & fill. Here's hoping it turns out to be PM and not DM (destructive maintenance.) With heart in mouth & fingers crossed.
And the fluid I use is a secret. I refuse to re-open that can of worms. :rofl:

Last.
bmw_n00b13, I don't mean to rant on or pick on you. Or anyone else for that matter.
Actually, I share the frustration expressed by you and many others. I really wish that TIS was more explicit in its procedure.

 

[Jason5driver]

I like using Mike Miller's old-school maintenance schedule...
http://forums.bimmerforums.com/forum....php?t=1271469

 

[gibo58]

over/under filling ATF

Wouldn't it be prudent to do as others have mentioned and accuractly measure what you drain out and put back in the same amount of ATF?

Could you place a spririt level or inclinometer on the tranny pan to check for level?

I'm at 100k so am debating my options after reading loads of threads.

 

[JimLev]

Spirit level is probably the best way to insure it's level.
Measuring what comes out is OK as long as it was full (no spills or leaks) before you started.

 

[Fudman]

I'm continuing to monitor how my tranny is shifting and with the "normal" ATF level, it has definitely changed the shift point downward to where it used to shift (2,300-2,400 rpm under mild acceleration). It was shifting in the 2,600-2,750 range with the higher ATF level. I am now wondering if the increased "noise level" with the higher ATF level is simply associated with the higher engine rpms of the higher shift point. I just can't understand why a tranny would be noisier with just a little more ATF. :dunno: Anyway, the tranny is shifting fine.

Ultimately, I do not think my experience should discourage anyone from changing their ATF fluid. I just think that one should be very careful in how much ATF you put back in. The "what goes in = what comes out" is a sound approach if your tranny is running properly before the change. Clearly, "more is better than less" but needs to be executed with caution as "too much of a good thing is bad".

 

[doru]

I'm continuing to monitor how my tranny is shifting and with the "normal" ATF level, it has definitely changed the shift point downward to where it used to shift (2,300-2,400 rpm under mild acceleration). It was shifting in the 2,600-2,750 range with the higher ATF level. I am now wondering if the increased "noise level" with the higher ATF level is simply associated with the higher engine rpms of the higher shift point. I just can't understand why a tranny would be noisier with just a little more ATF. :dunno: Anyway, the tranny is shifting fine.

Ultimately, I do not think my experience should discourage anyone from changing their ATF fluid. I just think that one should be very careful in how much ATF you put back in. The "what goes in = what comes out" is a sound approach if your tranny is running properly before the change. Clearly, "more is better than less" but needs to be executed with caution as "too much of a good thing is bad".

The key sentence is : "if the tranny is running properly before the change".
Because, one might have a slight leak and have lower ATF level. Happened.
Then, you end up with low ATF. Best way is to double check the level. If you have a GT1, you can check it very easy. If not, the Bentley method is pretty accurate.
As Jimlev mentioned, you can place a level on the roof, once the car is on jackstands.

 

[JimLev]

Not the roof, don't think is has a flat spot on it.
Stick a magnetic level on the tranny pan as Gibo58 had suggested.

 

[doru]

Not the roof, don't think is has a flat spot on it.
Stick a magnetic level on the tranny pan as Gibo58 had suggested.

Snap!!!! good idea.
I used the level right behind the moonroof - I know my garage is level, and there was no reason to have the car cockeyed once on jackstands, but I placed the level nontheless just to see (in case I need to check "level" if I'm not in my garage) and it was level. But, yes, the roof is convex and you need a small level.