6speedshifty

Is this a worthwhile upgrade? I asked the BMW dealership about it and they acted like I was crazy for wanting to put motor oil in my transmission. What weight oil is recommended? Does it make a noticeable difference? Thanks for the advice.

Z-07 freak

Castrol 10w-60 synthetic

GS345

Mine seems to shift alot smoother than before. The oil is Castrol TWS 10w-60. The cost is not too much more than the GM stuff.

jeff

ToyC4

The OE transmission lubricant is 5W-30 viscosity mineral based oil. The ZF transmission company also approves of the use of Castrol 10W-60 synthetic lubricant. The thicker viscosity lubricant is useful for dampening transmission noise. A synthetic lubricant is also more stable in viscosity as temperature increases.

tsts

I put it in mine a few weeks ago (97K mi.) but have only driven it a couple hundred miles (winter weather). It is quieter and smoother.

Perfusion

No offense, but you can't expect a BMW parts counter guy to know diddly squat about 'Vettes and the associated fluids that they can accept. FWIW, I even asked my 'Vette mechanic about the BMW oil, and even he'd never heard of doing it. It *is* frequently done by those who have easy access to the Castrol stuff (i.e., people aren't driving 100+ miles to get it), and there haven't been any negative results that I've heard. Don't expect a "miracle", though. A tranny fluid change is a fluid change. If your ZF6 *really* needs it, it probably doesn't matter *what* you put in it - so long as its fresh!!!

rocco16

I put the Castrol/BMW motor oil in mine...no discernable difference, but it sure didn't hurt anything either.

Larry
code5coupe

froggy47

Just put the TWS in mine (55k miles). Previously I had done a change with the 5w-30 gm oil.

TWS is better

next year I'll try the RedLine MTL, supposed to be very good also & avail by mail if you don't live near a BMW dealership[.

ClarenceT

I did it, and it's better.

Castrol TWS 10w60 is what you're after, it has nothing to do with "BMW" other then they sell it since it's factory fill for M3/M5 motors. You can get it other places too, probably for less. i got lazy and went to the BMW place down the street out of sheer convinience, but it was damn expensive - $25 for 3 quarts.

Atok

Ya, it's expensive but $25 seems cheap compared to the local BMW dealer here in my neck of the woods in Canada. I paid $20 Cdn per Litre which is roughly $14 USD per quart. BMW is the only place to get it around these parts but it's worth it!

rocco16

Yeah, $12/qt. here in Sunny Southern California.
Ouch.

Larry
code5coupe

bogus

I got my last batch at the BMW dealer here in Torrance, 8.00 a litre. Same price I paid in Delaware.

A little about oil here... transmissions have different requirements for oil than do engines. Inside a tranny you have sheer forces that simply don't exist inside an engine. It's one thing to protect against two things rubbing, but when they are changing tension and pressing, that's a problem.

The TWS 10-60 has the additives required to meet that need of sheer forces. Additionally, so does the GM fill.

Most other motor oils do not have those additives. The downside, they don't list those that do, it's hit and miss to see if they do or don't work.

This is why selecting oil for the transmission is so very important. It's why I don't mess with anything other then the TWS 10-60 or the GM fill.

There are other options - according to ZF, ATF is ok, but I would be a little less then comfortable to use it.

ToyC4

I bought three qts from the local BMW dealer today and it was $28.60 but they said list price is $12/qt. The BMW part number is 07-51-0-009-420. I'm still arguing with the shop that's doing my motor - "it's a transmission and we're going to put transmission fluid in it" - whatever! These are the same guys that don't want me to use synthetic oil in my motor they seem to think it's a tool of the devil or something

byebyeL98

Castrol also makes a 5W-40 (i think) synthetic oil that says "specifically designed for BMW engines" on the label. you could probably use that as well, as i would imagine it has the additives Bogus is referring to.

Either way - it's a good idea to change it at least every year, more often if you are racing a lot.

Sleazy Rider

tried the MTL in my 89' 6-spd. trashed the trans. three gears. now i got an expensive boat anchor. i've gone back to the gm

ToyC4

dang man that sucks but it's good to know thanks for the info

TrackDayLT4

I've been using MTL in my '96 for 6 years. The total is about 50K street miles and 5K track miles. Mine still shifts better than it did when new with the GM stuff in it.

Cheers,

Lawrence

Sleazy Rider

well, i just don't know. all i know is right after i put in the MTL, my trans went south. bought a used zf from contemporary, in 96, and am running gm fluid and not having any problems

jay007

I use royal purple 10w 30 in my zf. shifts like new.

bogus

That might do it... The lable on the 10-60 says something like "meet special duty requirements of the Porsche 911 Turbo and BMW M5."

If the 5-40 says the same kinda thing, I would expect it to be ok.

The key here is the friction modifiers.