Automatic Transmission Question

A few months back my 1992 525i Touring Wagon's auto tranny decided to die,
slipping in each gear. At 150,000 my mechanic recommended changing the
tranny oil, and shortly thereafter the problems ensued.

I took my car to supposedly the best BMW auto transmission place here in
town and after hearing the story, he said the problem was that BMW uses
their own proprietary fluid for their transmissions, which costs about $120
a liter. Using another fluid could very well cause problems.

Has anyone else heard this or can verify that? Thanks.

Scott wrote:

> A few months back my 1992 525i Touring Wagon's auto tranny decided to die,
> slipping in each gear. At 150,000 my mechanic recommended changing the
> tranny oil, and shortly thereafter the problems ensued.
>
> I took my car to supposedly the best BMW auto transmission place here in
> town and after hearing the story, he said the problem was that BMW uses
> their own proprietary fluid for their transmissions, which costs about $120
> a liter. Using another fluid could very well cause problems.
>
> Has anyone else heard this or can verify that? Thanks.


Several mistakes here..

If the fluid had never been changed in 150K miles - your mechanic did
you a disservice. Changing the fluid dislodged some crud (tech-term)
that then circulated around the transmission, stopping in rather bad
places and causing your problems. To fix it - at a minimum the valve
body and solenoids will need disassembly and cleaning. At worst case -
the entire transmission will need disassembly, cleaning and rebuilding.

OK - second mistake - if this is a US/Canada car - the transmission is
the GM/Strausburg one BMW installed for the colonies. It is very similar
to a number of other GM transmissions used in other cars of the era, and
shouldn't be a mystery to a rebuilder. This transmission is designed
to use Dextron-II (which has been updated to Dextron-III), which costs
about $2/quart. It will run just fine with this fluid - standard AT
fluid. Later models did use some mystery fluids - but not in '92.

Suggestion - have the fluid changed and the filter cleaned several times
in a row. This MIGHT flush out the bits of crud that are causing the
problems you're having. If that doesn't work - visit find a reputable US
transmission shop - some of them have a machine that power flushes the
entire transmission.. this might dislodge bits that are stuck in bad places.

HTH

In article >,
Scott > wrote:
> I took my car to supposedly the best BMW auto transmission place here in
> town and after hearing the story, he said the problem was that BMW uses
> their own proprietary fluid for their transmissions, which costs about
> $120 a liter.

Go to someone who knows what he's talking about.

--
*INDECISION is the key to FLEXIBILITY *

Dave Plowman London SW
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