transmission fluid

[jrindin]

i have a'94 530iA. my new mechanic just told me that if i haven't changed my transmission fluid in awhile, that i should not change it. that the result would be that the new fluid would eat through all the seals and result in needing a new transmission. he said just let it be if i'm not having any problems.

thoughts?...

[John B.]

Find another new mechanic!!

[BillionPa]

ditto....


if you FLUSH the fluid you can have bad results. what you want to do is change about half of it, let the varnish slowly get picked up by the filter over about 10,000 miles, then change it.

[John B.]

I'd think you would want to get a new filter in there to start with as the old one could be pretty full or clogged if the fluid hadn't been changed in a long time.

[jrindin]

so if its done in stages, then it should be ok. if i changed the filter, then i guess the old fluid should be saved and half of it put back in.

[632 Regal]

close, ZF's procedure is to change the filter and the fluid that comes out with it only, about 3.5 quarts, every 30,000 miles. Try to get synthetic dexron III, royal purple makes one and it is very reasonable. Get an OEM filter, something about the seals leaking air if you go with the aftermarket types.

Inform this to your mechanic, he just hasn't spent enough time researching this particular transmission... the ZF5hp-18.

there is also a specific temperature the trans must be to get the correct fluid level too. Trans should be 100 degrees F, idling, on a level surface. 100 degrees being if you hold you hand on the trans pan it should be uncomfortably hot to hold your hand on it.

so if its done in stages, then it should be ok. if i changed the filter, then i guess the old fluid should be saved and half of it put back in.