Changing Transmission fluid

transmissions
fluids

#1

I have a 2001 325 with 100k miles on it. I dont now believe that the transmission fluid has ever been changed. There is alot of discussion on the bmw “lifetime” transmission fluid, however about 6 months ago, they now recommend changing it at 100k miles.



My question is, is a 100k mileage too late to change the transmission fluid? It seems like a flush is out the question, but is just dropping the pan and draining half the fluid good enough?



So far I have had no problems with my trasmission, but would like to do PM work. and the same question applies to the diff fluid as well.



Thanks for response.



Aqeel


#2

So change it already. What’s the question? It’s time.

A F&F won’t change the filter, but will get MOST of the fluid. Dropping the pan will allow you to change the filter, but only part of the fluid.


#3

Drop the pan, change the filter, and refill with clean fluid. Avoid flushing.

Replace the differential oil, too.


#4

Drop the pan, change the filter, and refill with clean fluid. Avoid flushing. Replace the differential oil, too.

I agree.  You never get 100% fluid change, but unless you know there is a serious problem with the fluid, I believe that the drop with filter change is the best bet.  The flushes, while they may (or may not) change more fluid, they don't replace the filter. 

I will add one additional note.  It is not uncommon for a transmission to fail not long after doing either type of service.  Of course since most people don't service their transmission until it has some sort of a problem, it is usually a case of too little too late.  Servicing a transmission that is not showing any bad signs will only extend its life.

#5

As already stated, fluid & filter change would be OK as long as the transmission is working OK now. A qualified shop can then also make whatever adjustments are needed. Use long life transmission fluid approved by BMW.


#6

Never too late unless the transmission is failing.