Changing "Lifetime" Trans/Differential Fluids

[spisut]

Interested in thoughts and experiences on changing the "Lifetime" Auto Trans and Differential Fluids in a 1998 E39 528i. My 528i currently has 46K miles. Should I leave these fluids alone? Wait until 60K miles to change? If change, where should I take it to be serviced?

[TMB_540i]

Lifetime fill is great PR for BMW when they are paying for the service. But if you are keeping the car around a while and want trouble-free service, I would change the differential fluid and transmission fluid (manual or automatic) every 2 years, especially if you track the car. I use Amsoil SevereGear 75w90 Synthetic Gear Oil lube for the differential and I use Royal Purple Synchromax for the manual transmission fluid. For the automatics, I use Amsoil Synthetic Universal Automatic Transmission Fluid. You can also refill with BMW fluids or go with other Synthetic products like Redline. It is easy enough to do the drain and fill yourself but any competent facility should be able to take care of it for about an hours worth of labor. I think the automatic transmission is a bit more involved since I believe you drop the pan and change the filter, so maybe a bit longer for labor.

[spisut]

Thanks Tom. Figured this was something that I needed to do. I do not track this car... mainly my wife's daily driver. But since this is a 1998, sounds like I need to get this done soonest as opposed to waiting until the 60K mile service. Thoughts?

[slantsixm3]

Scott,
While I don't purchase automatics myself (maybe someday), I've been hearing about this "lifetime" atf for quite some time. If the factory fluid is this "unobtainum" stuff that sells for like $60/liter(or something equally ridiculous). it's likely to actually be good for 100k. Despite the conspiracy theorists, I don't think BMW serves it's own interests by selling a car that will collapse at 90k miles.
The consensus that I have seen, that makes sense to me, is to replace the fluid and filter at 60-100k, and to suck it up and use the BMW fluid. It apparently really is different, and the trans is specifically tuned for this stuff.
Now I'm sure 20 people will relay tales of how they are using recycled BillyBob's ATF and it's working just fine. Take your pick.
All the gear mechanisms in my 1998 M3 get the Redline products that Redline recommends for the application, which also exceed BMW specs.
Remember, advise on the Internet(mine included) is worth exactly what you pay for it.
No matter what,
enjoy your BMW.
- Joel B.

[Pinecone]

A lot of the extended fill/lifetime fluids were prior to free maintenance.

But even so, I agree that changing is a good thing. I run Mobil 1 in most of my diffs. BMW fluid in the E46 M3 since that diff is special.

Trannies, I run Redline, Mobil 1 or BMW LTF2 (about $20 per liter). I only have manula BMWs. I used to run Mobil 1 ATF in auto trannies, but the current Jeep Grand Cherokee uses a special tranny fluid that is either Mopar, Pennzoil or Castrol.