Change "Lifetime Fluid" Automatic?
 

I just bought a 1999 528iT with 103,000 Miles and no service records, and I just don't trust this lifetime Automatic Transmission Fluid. I have to assume the previous owner never changed it. The car shifts just fine, but of all the people I ask, half say "Change it" while the other half say you will dislodge deposits that can clog oil passages, or the removal of floating friction material will cause surfaces to slip and burn up. So what's the deal, change it or not?

I just learned my car (11/98) could be either a A4s310 or A5S360 transmission, so I need to get under it and check it out. Now, the A5S360 takes the special $25 a quart fluid, while the A4S310 takes good old Dexron III. They claim the Dexron III was good for Lifetime interval as of 9/95. Now, you could POSSIBLY convince me the liquid gold is good for a lifetime, but how could Dexron III need to be changed in a car built 8/95, but the exact same fluid does not need to be changed in a car built 10/95. I detect a load of bull....

Yeah, lifetime fluid is not cool. I would switch it out with good stuff, like Royal Purple. Just don't use Redline fluid, or you'll be geting a reman in no time.

According to the copy of SD92-113 that I have, 528i and 528iT used the A4S270R from 2/96 through 8/99. This is a GM designed, European built, four speed with 4th being overdrive.
Translates thusly: A4S 270R/310R = 4L30-E = THM R1.

And it uses Dexron III. SD92-114 gives the fill and check level procedures. And the figures will further assist you in determining which tranny you have. Pan shapes are COMPLETELY different.


BTW the A4 = 4 speed, A5 = 5 speed. Whatcha got?

You can D/L these docs from www.bmwtips.com in PDF format.

And there should be a decal/sticker on the bottom of the tranny pan that specifies what ATF to use. (But it only gives the BMW PN I think.)

BMW's "Lifetime"? Translation = 100k over-all vehicle warranty period. That's all they care about.

My advice. DO NOT FLUSH! Drop pans (one front, one rear on my 99 528i), clean'em spotless, replace filter, replace pans with new gaskets, torque bolts PROPERLY, refill w/Dexron III IAW procedures to include taking its temperature. (Digital meat thermometer stuck thru the filler hole and into the fluid works fine.
Run it 5k or so, drain it via the drain plug and refill. Do it a couple of times and you'll have effectively changed the fluid WITHOUT worrying that a blast of pressurized ATF might knock some of the crud loose and plug a passage somewhere.

Change it if you intend to keep the car any length of time!!!!

I have recently purchased a 99 540i and about to change the "Lifetime" auto transmission oil (the expensive Esso LT 71141 stuff). BMW Dealers here say "don't do it" - but independant repair shops say the opposite.

My view is that if done with care and with the right fluid the risk is lower than leaving in old deteriorating oil.

Proposed Approach: 1) drop the old oil (cold) and accurately measure the quantity. Use this as a guide for the amount of new oil.
Have car raised level on four Jack Stands. See Pelican Guide for 3 Series on this site as a primer!!

2) Clean out the sump, magnetic trap and replace filter with a new one also replace sump gasket.

3. Follow the Z/F TRansmission guide ie correct temp range with car level and top up through filler hole until the oil runs out.

4. Repeat the Drain/Fill process after say 1000KM and this should pretty well give a "clean" environment for the tranny to last a lot longer!!

If anyone has done this on the 540 and can add some further advice pls let me know.