1st gear slip/shudder under heavy throttle only.

Hello,
Recently purchased 95 BMW 540i with 193,340 miles. Trans operated correctly until performed basic fluid\ filter change. Had pan off over night, refilled with AMS-OIL ATF, 6 qts. Thought was full, fluid perking out fill hole. Drove and found to be slipping in drive. Raised back up and added another 3 qts ATF. Car now will very intermittently slip/shudder when accelerating from stop with light throttle. Under heavy full throttle, car will also intermittently slip from stop. I also noticed problem began to be more prominent when slowing to below 8 MPH then accelerating. Like the GM 4L60E slip bump in the C/K series trucks. I removed pan after initial fill to be sure there were no "metals" in pan or unplugged wires or missing filter O-ring, all was good. The trans goes into fail safe every time except when trans slips/shudders under light throttle. Any one out there have any help or input with this scenario? Thank You.

No ideas right now, but here are my symptoms/info.

Car has 150K, however BMW replaced tranny at 100K. ZF tranny with life-time fluid and I have not changed it.

A few months ago I noticed when I slowed down to make a turn, and began to accelerate the car would skip/ hesitate/shudder. Later I noticed it would do the same thing when pulling off from a stop. On long trips it appears to act up more and feels more like a tranny slip. This is all intermittent and only happens a small percentage of the time.

I have researched and most suggest checking fluid level. I have the procedure and will try this weekend.

Rick

Originally Posted by sfoda764

No ideas right now, but here are my symptoms/info.

Car has 150K, however BMW replaced tranny at 100K. ZF tranny with life-time fluid and I have not changed it.

A few months ago I noticed when I slowed down to make a turn, and began to accelerate the car would skip/ hesitate/shudder. Later I noticed it would do the same thing when pulling off from a stop. On long trips it appears to act up more and feels more like a tranny slip. This is all intermittent and only happens a small percentage of the time.

I have researched and most suggest checking fluid level. I have the procedure and will try this weekend.

Rick

Well, if you are running low on tranny fluid and you don't have a leak, then you would have had this problem right after your transmission was replaced, similar to what the OP experienced. So I don't think that's it.

I suspect that its your clutches....they are getting worn, hence the slippage.

If i've guessed correctly, then the only way to fix that would be through a rebuild. One way to forestall a rebuild and reduce slippage would be to use thickening additives, or to change to a thicker tranny oil entirely.

Originally Posted by lexisbmw540i

Hello,
Recently purchased 95 BMW 540i with 193,340 miles. Trans operated correctly until performed basic fluid\ filter change. Had pan off over night, refilled with AMS-OIL ATF, 6 qts. Thought was full, fluid perking out fill hole. Drove and found to be slipping in drive. Raised back up and added another 3 qts ATF. Car now will very intermittently slip/shudder when accelerating from stop with light throttle. Under heavy full throttle, car will also intermittently slip from stop. I also noticed problem began to be more prominent when slowing to below 8 MPH then accelerating. Like the GM 4L60E slip bump in the C/K series trucks. I removed pan after initial fill to be sure there were no "metals" in pan or unplugged wires or missing filter O-ring, all was good. The trans goes into fail safe every time except when trans slips/shudders under light throttle. Any one out there have any help or input with this scenario? Thank You.

This is unfortunately a common occurrence. You are not the first person to experience transmission problems in an otherwise normal tranny, right after a fluid change to NEW fluid. Someone should really post a warning about this in the sticky thread on maintenance.

About a year ago, there was a german or Portuguese chap with this same situation. He solved it by changing the oil to either valvoline, havoline or royal purple high mileage transmission oil. I believe it is thicker than regular tranny oil. Perhaps you could give that a go ?

Some say that the oil pump in the tranny is unable to tolerate the thinner fluid, having been deformed by the increasingly thicker old oil thus far. Perhaps that is true, perhaps not. In any case, you might benefit from getting a professional's advice....not that they aren't here, but perhaps a shop that can see and test drive your car directly. You can listen to what they have to say without doing what they recommend right away...come back and let us know your research and we can help you decide the best course forward. This is an problem that we really should solve for everyone's sake (well, at least for the sakes of the members with automatics )



rgds
Roberto

I think you already messed it up pretty bad. Is the fluid on ZF's approved fluid list at right specification? Did you put filter/etc properly?

I experience the same thing with mine. I know It's the converter on mine. It even trips a code or two for it. I would scan it to double check. But roberto has the right idea. Probably the clutches in the torque converter. There really expensive from the little looking I've done. So I'm counting the days my car drives forward.

Also my car responded very well to the oil change. I used carquest ATF Dex/Merc IV I believe. I don't believe the oil has that big of an effect on things as long as It's the right type.

My problem was corrected with replacing the spark plug wire/tubes.