change oil on transmission ?

Here's one opinion.

Having just had an inspection 2 in which the transmission oil change is recommended in the service book, I questioned why they hadn't changed the transmission oil. The dealership said that they had spoken with BMW HQ and the current recommendation is not to change the oil unless there is a problem. Apparently they have been finding that more problems arise after changes than by leaving it alone. I got the impression the old Detroit theory applies, "If it ain't broke, don't fix it"

My .02p's worth....

ZF themselves recommend change oil regularly. Cant remember how often but 30k seems to ring a bell.....

I would call it preventative maintenance but do use the correct oil.

And to fully change all the oil it would take 2 changes!!!!

Alex

I did my own Gbox oil change , had a small leak when reassembled & running so drained it all over again & got it right 2 nd time so quite possibly I may have got all of the original oil out;-)

The upside , is much smoother changes & piece of mind

Not all gearboxes are "lifetime fill" and the ones that aren't - mostly the 4-speed ones- use mineral-based oils (Dexron III) and require a regular change.

The is a lot of split opinion with the regards to the "lifetime" fill geraboxes.

Typically, BMW garages would never change the oil on these quoting the "lifetime fill".

After some years, it was found that the carbon friction material (that replaces asbestos) on the clutches and brake-bands tends to partly leach out into the oil. Therefore, an oil change is recommended after about 60,000 km, after which there should be no need for a futher change.

However, there is some statistical evidence to suggest that gearboxes that have had an oil change, may then fail sooner. But this is probably due to the gearbox not being refilled to the correct level.

By the way, it's not possible to easily drain all the oil as about 1/4 of it remains in the torque converter. and some problems can also arise by trying to remove the remaining oil in an incorrect manner that may cause debris to enter the valve block. Just changing the oil (and filter) that is in the sump should be adequate.

Different dealers say different things.

I plan to change my oil.

I recommend replacement of the transmission oil on a lifetime fill autobox every 50000-60000 miles together with a filter (and of course a sump tray) gasket. I have never had one fail after this has been done, regardless of the pre-change mileage.

I suspect a few things of note here:

1, It's a messy and unpleasant job to do so technicians will try and get out of doing it.
2. There is a proper procedure to follow during refil and if not done correctly, leaves the transmission low on oil and you have no dipstick to check it with!
3. You are lucky if a dealer changes your fuel filter that is fiddley, let alone the transmission oil.
4. Owners dont think of changing the oil unless there is a noise or funtionality problem with the box and they hope changing the oil will somehow repair the transmission, then when it later fails, they blame the oil change,
5. The transmission manufacturer recommends oil and filter changes, it is BMW who do not. Hoping to supply a few new gearboxes to the later owner perhaps?
6. The oil is expensive and dealers need to buy a barrel of it and hardly ever use any so there are cost and storage considerations for them.
7. Up to 1995 cars, it was part of the Insp 1 service to check the level and top-up or drain and refill on an Insp 2. As I said in 3 above, unlikely that was ever done.

I assume we are discussing auto transmissions because all manuals should have the transmission oil done every Insp 2. Diff oil changes are another neglected item but at £86.00 + VAT per gallon, I'm not surprised.

I have changed many board members transmission fluids here and would like to hear from them of their experiences following the fluid changes I have done for them. About 12 of you.

Anyone?

8Tech.

Gerry changed my auto transmission oil

No problems at all!

My local BMW garage have said they will sell me the lifetime oil at "a discount".
I have a pit in my garage so may tackle the job myself, depending on its complexity - nobody near me, dealer or independent will take on the job.

If I decide to take a day trip to Surrey - how long would it take to have the job done uber-professionally?

I probably will have to change the oil in mine. It is probably running on the original oil from the factory. What oil shoul I go with for my 1991 auto 850?

A good quality Dexron-III oil should be fine, but there are some synthetic substitutes that could be used. See Fuchs oils.

transmission oil reference guide

Hello,

have a look on the attachment - there is an official oil referenz guide from ZF

bye

peter

Zitat von ukzero;82045

My local BMW garage have said they will sell me the lifetime oil at "a discount".
I have a pit in my garage so may tackle the job myself, depending on its complexity - nobody near me, dealer or independent will take on the job.

If I decide to take a day trip to Surrey - how long would it take to have the job done uber-professionally?

Drop off in the morning before 9.00, will be ready by 5.00 with oil, filter and gasket all done. cannot do it as a while you wait I'm afraid but you can use the Fiesta diesel rocketship for the day.

Zitat von 8Tech;82080

Drop off in the morning before 9.00, will be ready by 5.00 with oil, filter and gasket all done. cannot do it as a while you wait I'm afraid but you can use the Fiesta diesel rocketship for the day.

Thanks - that could work out fine.
Could any tired rear suspension bushes be done at the same time while the car is up on the ramps?

Yes, if we know beforehand and get them in stock. We keep the HD trailing arm bushes but do not keep the upper arms or hub joints here.

Really, we are breaking into a 2 day job here, 1 to diagnose and order, 1 to fit.