vstol

96 ZF, I have seen a few comments on what tranny fluid to use , will try this thread one more time. Best fluid to use in the ZF? Thanks

CentralCoaster

Nobody here knows. All you'll get are opinions.

The only "approved" lubes are BMW Castrol TWS 10w60, GM 12345?? 10w30 lube, and possibly an Amsoil mix that claims its a substitute for the GM lube.

bogus

froggy47

IMHO Castrol TWS 10-60. Just bought some this week to do mine (once a year, track/autox car)

dizwiz24

Do not go with the Castrol BMW stuff for your transmission. You run some major risks.

I went with this stuff in 2004 and got grinded shifts under hard acceleration and had to abort drag runs on a few occassions when the gearshift lever wouldnt move to the next gear. I thought I had a problem with the synchros on my ZF6 (w/ 43k miles) on my 93 vert.

I went and replaced/bled the clutch master/slave just as a precaution. The problem still existed. I emailed zfdoc of my dilemma. He suggested that my synchros were shot and he could rebuild it -at a cost of thousands of dollars.

All these problems went away after I switched back to the gm factory fill 5w-30 oil (do not use regular 5w-30 as it doesnt contain the right modifiers).

Scientifically, I believe the bmw stuff (since it doesnt contain the right friction modifiers (- its motor oil) causes major problems especially when cold. Many of the forum members here live in warmer climates and post about how great the stuff is. Maybe true for them.

If I was in your shoes. Heres how I would see it:

A. I can take some major chances by putting a part that is not recommended by gm into my $x000.00 transmission and maybe get some smoother shifting as my only benefit.

B. I can use the part that gm recommends and not have to worry about grinded shifts and 'gearshift lever freezeup' at the possible expense of 'not as smooth' shifting. (I actually had notchier, worse shifting with the BMW stuff).

Hmm. grinded gears, missed shifts, my choice of oil would be clear.

Im not the only one here who's had problems with the Castrol BMW stuff either. Around March-May of last year somebody else posted in either C4 General or C4 tech about the optional fill of the Castrol stuff. He too had the same problems that were cleared up when going back to the gm stuff.

Red Tornado

i live in PA, and my climate isn't much different than yours.

i've had the castrol stuff in for 2 years and about 8,000 miles now (will change by end of summer, time's up), and had zero problems with it.

you do bring up an interesting point about the gm fluid having certain "friction modifiers".

C66 Racing

The AMSOIL Synthetic Synchromesh Transmission Fluid (5w30) was released last year specifically for applications such as this. It is labeled for use for GM 1052931.

the blur

ins't the GM stuff motor oil too ??

neat

Try searching a bit for this information. There is another topic on the front page about this as well.

Clogging/cluttering up the forum for this kind of question is not a super big deal, but if you take a few minutes to search you can ususally find what you need without bogging down the forum. Common questions like fluid selection are especially easy to find using search. An advanced search for "ZF6 fluid" returns 24 threads that contain the information you are looking for:

http://forums.corvetteforum.com/show...ight=ZF6+fluid

http://forums.corvetteforum.com/show...ight=ZF6+fluid

http://forums.corvetteforum.com/show...ight=ZF6+fluid

http://forums.corvetteforum.com/show...ight=ZF6+fluid

http://forums.corvetteforum.com/show...ight=ZF6+fluid

etc...

I'm not trying to break anyone's ***** or anything, just pointing out that the information you are seeking has been given out over and over again. You could get to that information via searching in less than 1 minute, or you can post and wait potentially for hours or even days to get a response.

Let us know what you decide to do.

the blur

I want to know if the GM fluid container says ZF trans fluid, or say motor oil !!!

Sidney004

Went through the same dilemma a couple of months back. Selected the factory GM lubricant. Perfect shifts. Buy the factory stuff.

dizwiz24

quote:

I want to know if the GM fluid container says ZF trans fluid, or say motor oil !!!

--------------------------------------------------------------

It says Transmission fluid and was in a black round container with a skinny neck (not a motor-oil type plastic container). It had a blue and white GM logo'd sticker on it. I believe it said transmission fluid or something of the liek

CentralCoaster

I just finished using up the rest of my bmw fluid, I'll switch to GM next fillup and report back. Shifting is notchy with the bmw fluid.

neat

The GM recommended fluid has been replaced by another part number and is called Syncromesh transmission fluid. The new fluid is probably OK, but I don't think GM has published anything specifically stating that it is an acceptable fill for the ZF6, atleast not that I can find.

Bigredwing

I went with the synthetic Castrol TWS and have had no problems through the end of winter to now but I don't drag race or auto-x. I would like to see a post from somebody that uses the new part number GM sychromesh fluid. How many miles and how the car is used would be helpful. Thanks!

vstol

Thanks Neat for some reason when I did the search I did not come up with much.
,

PacWest

I've had the new Syncromesh in my 96 CE for 2 months and about 1K miles. I have not had any problems. I did not notice any difference after changing it. If I"d known about the Amsoil MTF I would have probably used that.

-Ryan