2004 E46 318i Trans Fluid

[MadMaca]

I am trying to find information on how to check my transmission fluid level as my trans has started aggressively slipping into gear, i am aware that it could be a sealed transmission, is this the case and if so how would i get to it?

[MarcoZandrini]

The only way to check the fluid level is by removing the fluid fill plug. To complicate things, the transmission has to be slightly warm (fluid pan temperature needs to be about 125*F).

Be advised that BMW sourced automatic transmissions from ZF of Germany and GM of France. The easy way to tell which transmission is in your car is to look at the transmission fluid pan. If the pan’s sides are smooth the transmission is a GM. If the pan’s sides are ribbed the transmission is a ZF. Why does this matter? They take different fluids. The GM transmission uses Dexron3 (Dexron6 is the synthetic version). The ZF transmission uses a more exotic (and expensive) fluid. All of my 5 bimmers have had a manual transmission so I’m not up to speed in fluids.

BMW used to tout “lifetime fluids.” Lifetime fluids was a marketing ploy and not a maintenance philosophy. I recommend that you find a reputable independent (indie) shop that specializes in bimmers in your area. Have the shop scan the automatic transmission computer (EGS in BMWspeak) for codes. If you’re in the US try www.bimrs.org.

[Honolulu]

Hee haw, lifetime filled trannies. Actually, they were correct, but in a way no one wants to acknowledge. As you may not have heard, I shall now proceed to relate: If you fluid goes bad and your tranny fails, that's the end of you car b/c they cannot be economically repaired. So, life of the trans fluid is the life of the car.

IIRC, you drain the fluid, maybe r&r the filter. Close it up, put in a quart less than the recommended fill amount, and warm up the trans. When sufficiently warm add fluid from the side hole until it starts to overflow. That's enough. Now, the trans and fluid in it will be dam* hot, so protect yourself accordingly as you add the last however much. I've done this a couple times on wife's MB and maybe one of my bimmers, forget which.

[E39 Newbie]

The 5HP19 trans can be economically repaired. You can DIY it for a few hundred dollars, assuming one is already comfortable doing a lot of their own work. Otherwise, around here a rebuild, including removal and replacement, runs in the $3.5K neighborhood. Not cheap, but reasonable by BMW standards.