Auto transmission mounts = money shift- repaired twice, still worn, help!

[alex 1993 525i auto]

Hi all,

I have a recurrent problem with my transmission mounts (auto trans)... It does the caracteristic 'money shift', I mean that when the transmission upshift (1st to 2nd, etc.), I hear a metallic sound from the rear of the car, like if you play with quarters in your pant pockets... It was diagnosed by my independant BMW repair shop as worn transmission mounts.

The car: 1993 525i automatic, 216k miles.

So they were replaced last September, so 7 months ago (at 208k miles). Indeed they were worn badly, and new auto trans mounts fixed this issue. But only for a while. 2 months later, it started to behave the same... So in december 2007 my mechanic replaced them again (on warranty, at 210k), he showed me the mounts to tell me they had soften way too much.

It ran good for a little, and now at 216k, 4 months later, the issue reappears! There is no transmission leak at all which could soften the trans. mounts. A little bit of oil leak, from the oil canister housing (5 pints of oil added in 6k miles) but it drops down the oil pan, which is way up front than the trans. mounts...

Anyway, transmission mounts should be made of oil resistant rubber, right? Any idea what would cause those mounts to fail so readily?

Thanks for your help, Alex

[bubba966]

How are the engine mounts?

Your tranny mounts shouldn't be failing that soon. Hell, in that car they should last a good 100k or longer.

Were the mounts used factory mounts, or some cheap no name off-brand ones? I can see a possibility for no-name mounts having poor quality control and not lasting very long.

If I was you, I'd call up UUC Motorwerks and get a set of their tranny mounts (the owner of the company said that they should work for most all autos even though the site only lists manual applications. And as they've been installed in the occasional auto, I'm guessing that those applications were the same as yours).

I'd also take a good look at the engine mounts.

Something is either poorly made (off-brand mounts) or it's moving too much due to something else being broken (engine mounts) or something isn't aligned in the proper manner (like the pre-load wasn't set on the center carrier bearing in the driveline).

[alex 1993 525i auto]

Thanks for your infos Bubba966! Some answers and more questions to follow:

How are the engine mounts?

Your tranny mounts shouldn't be failing that soon. Hell, in that car they should last a good 100k or longer.

Were the mounts used factory mounts, or some cheap no name off-brand ones? I can see a possibility for no-name mounts having poor quality control and not lasting very long.

They should be factory mounts. I did not ask at that time but this shop is very knowledgeable and I doubt they would use off-brand parts (this BMW specialized shop replaced my lower control arms with 750i bushings, telling me those were longer lasting than 525i...).

If I was you, I'd call up UUC Motorwerks and get a set of their tranny mounts (the owner of the company said that they should work for most all autos even though the site only lists manual applications. And as they've been installed in the occasional auto, I'm guessing that those applications were the same as yours).

I'd also take a good look at the engine mounts.

How do I check this? The engine doesn't shake on iddle or rev. it is all I can tell now. I will ask anyways at next service.

Something is either poorly made (off-brand mounts) or it's moving too much due to something else being broken (engine mounts) or something isn't aligned in the proper manner (like the pre-load wasn't set on the center carrier bearing in the driveline).

I'll ask about this last suggestion too, I don't know exactly what your talking about... sorry I'm a new DIY! (I did some basic work myself on the car like replacing heater valve, aux. water pump, ac microfilter, headlight assembly, Gearshift/neutral safety switch, Front left door bowden cable for opening door and window motor)


One more thing: the auto trans. mounts which were replaced are the rear ones.

Upon looking on realOEM site, I noticed that the pics doesn't match to the parts which were replaced??? It look like my rear auto. trans. mounts that I have since I got the car (older and newer ones) are the one for a manual transmission!!!

The parts that were replaced, and that I had a look at (worn), are rectangular shaped (look like the Tie-fighter of Dark-Vador in Star Wars kind off shape).

They are not disk shaped like the ones I should have for an auto. trans. (same look as the ones of UUC Motorwerks)!?!

Then another thing to drive me nuts, both of them (auto, manual), with different shapes, have the same part numbers according to realOEM 24701138427 (left) and 24701138428 (right)!?!?

Any idea?

[attack eagle]

yeah the picture is wrong.

they are both tie fighters (good analogy)

Front mounts ok? Engine mounts, Guibo, Center driveshaft support bearing...

[alex 1993 525i auto]

Thanks for everyone's ideas, I will have a my independant BMW shop look at this at my next service.

If anyone has more idea please let me know. I will let you know what was found asap!

[alex 1993 525i auto]

The problem was not enough oil in the tranny.... Was working well beside that. Last year I had the oil, filter and gasket replaced as well on the auto transmission and it curred the weird sound when shifting up for a while. Now 1 year later it is back... Beside topping off the trans. oil, I'd like to solve that for real.

I've found some oil spots who look to come from between both tranny oil sump. Any idea where the leak could come from? Is it possible to have a leak from a seal somewhere kind of close to that, that could also soften my auto trans mounts?

[BMW4LIFE]

okay so I have the same problem but I just did my tranny and filled it to the rim with the engine running and the tranny on N.

did I still need to add more?!?! Is it MY mounts?

thanks!

[genphreak]

okay so I have the same problem but I just did my tranny and filled it to the rim with the engine running and the tranny on N.

Are you not following the procedure religously? You will over or underfill if not, they say the tranny fails as a result. Symptoms caused by incorrect filling are not a good thing to see- they tell you you have screwed it up. Best to follow the procedur- it is vital to measure the fluid temp run it through the gears at the right points to avoid a bad fill.

[BMW4LIFE]

Are you not following the procedure religously? You will over or underfill if not, they say the tranny fails as a result. Symptoms caused by incorrect filling are not a good thing to see- they tell you you have screwed it up. Best to follow the procedur- it is vital to measure the fluid temp run it through the gears at the right points to avoid a bad fill.

I did every procedure...

waited to warm the tranny...drain it...fill it....heat the new tranny fluid for about 30-45 min...then check level...then fill...then run through all gears...then check level...then fill...then ran through all gears...then checked for leaks and finally tightened the fill screw all while the car was in N

[alex 1993 525i auto]

Update on that topic:

The metallic sound I was hearing (like a ding-ding-ding noise) coming from the bottom of the car was not from the transmission, it was the 'pinging' sound of predetonation (because of the working knock sensors), the sound was coming from the exhaust, not the automatic transmission. I cured it by cleaning the carbon deposits with Seafoam engine treatment, added the fluid in the intake with the use of the vacuum of the small hose from the pcv valve with the engine reving at 4k while the engine was already well warmed up. That produced a massive stinky white cloud. After the car had drunk the full bottle, replug the pcv hose, I drove on the highway at 4-5k rpm for 20 minutes. It cleared up the pinging sound.