wingnut96lt4

:sadangel I have a 96 LT 4 and want to change the transmission oil and read the instead of the 90 wt gear oil BMW makes a 10 60 oil which guys have used and is supposed to be just as good and even better . It lasted longer without breaking down. Anyone done this ??

WVZR-1

There was NEVER a 90W gear oil for the ZF, NEVER! The Castrol 10W60 is one of the possibilities that is frequently used. There are others. There's much for you to read if you just poke around. There's good choices and bad choices. The Castrol is a "better" choice than some, maybe most.

You need to remember just one thing. Before removing the drain plug you want to remove the "FILL" plug. The hex required is M17.

RollaMo-LT4

Do not use your "normal" gear oil in this transmission.

With that said, I am using Amsoil fluid.



http://www.amsoil.com/shop/by-produc...ont%2fmtf.aspx

QCVette

I like RollaMo-LT4's choice.

I was researching this too and came to the conclusion to try the Amsoil he recommended above. I just bought the oil and had to buy a 17mm socket. I will change it this week.

rocco16

Now, you can go back to the store and buy a 17mm hex wrench.

PLRX

The Best Choice

WVZR-1

I'm quite sure he purchased the hex-key socket BUT since you mentioned it I really like the longer hex key and use a 17mm box wrench on the short leg and the longer leg to just support it. If someone's over tightened it and most are over tightened you'll need some additional leverage and that's more easily accomplished with the longer hey key also.

I've never been a fan of the Amsoil "pushers/resellers" and I've got plenty of the original GM product I believe. I believe I'd avoid the Amsoil even if I didn't have the OE/GM stuff.

I believe regardless of the lubricant "frequency" of service is more important for long life and quality service from the ZF.

QCVette

Relax, I did get the 17mm hex socket.

Actually, I looked around for a while to find one in stock somewhere. I finally found them listed as a VW drain plug socket.

Klondike

Me Too ! I tried the Castrol and didn't like the way it shifted; Slow and sluggish like it was full of wet cement. The Amsoil shifts like hot butter. Plus it has an additive especially for the brass syncronizers in the ZF6. The hard shift from 2nd to 3rd is now smooth as silk.

Z51JEFF

Im using the Amsoil in the trans.Thought it did such an excellent job of keeping the cam chains quite in the LT5 that it had to be just as good in the trans,cant tell any difference between this and the Castroil.As stated,break loose the fill plug before you drain the oil.

scotth48

WVZR-1

And this VW part # WHT-001-937 will get you correct drain and fill plug. You need to specify this # because in later years they changed the plug to a "spline" drive but they service both. Some dealers want to sell/stock only the later. Less than a $7 or so purchase if you need.

FAUEE

I'm using the Pennzoil stuff, people generally seem to like it for the cars. My car had old fluids in it, so it was more important to me to get fresh stuff in than to get the best right up front, as I will likely flush it out again in a few thousand miles anyways.

Though considering the car is destined to be a track car, it will likely see fairly regular fluid changes and I may just go with a more inexpensive fluid on a more regular flush basis (that Amsoil stuff ain't cheap - it's over double the cost of the Pennzoil or others).

dizwiz24

Amen to this.

Use the bmw castrol crap for your bmw engine, not your zf.

And use the syncromesh for your zf6, and not your bmw engine.

lt4obsesses

Me as well, good stuff. Running for a few years now. Changed the oil out twice, and each time, it look so good I almost put it back in.

Sam Ruger

Isn't the 96 6 speed designed for BMW's 15-65 oil? If so, I called BMW and they don't sell their oil by weight and had no idea which one I needed.

Anyone know?

Paul Workman

After my ZF "froze up" in 6th gear, cruising at 70 mph, I learned from Bill Boudreau (ZF.doc) it is a not too uncommon phenomenon with this transmission.

It's a long explanation, but suffices to say Bill addresses the issue by enlarging the oil gallery feeding the carrier shaft (IIRC) shared by 6th gear AND the reverse gear. Bill told me if I was not to have him bore out the passage, to be sure to use a good synthetic oil, and he recommended to me to at least use the Castol TWS 10W-60.

Lifted from Bill's ZFdoc website

______________

(Q.) I just bought, at the local BMW dealership, 3 liters of the Castrol TWS 10W60 oil. I was surprised to see that it is motor oil. Not being a lubrication engineer myself, who did the investigation and determination that this product is compatible with and good for our ZF transmissions? Jim � Grand Sport Registry


(A.) Jim, the C4 Corvette ZF S6-40 6-speed transmission uses engine oil for lubrication. I was told by Jeff Henning, Warranty Administrator of ZF Industries North America, that Engineering of ZF Industries in Germany determined that the BMW imported Castrol (RS superseded by TWS) 10W-60 oil was the recommended alternative to the (GM P/N 1052931) factory-fill oil for use in the ZF S6-40 transmission. In effort to verify ZF Industries alternative lubricant recommendation, we ran our own test series on the BMW imported Castrol TWS 10W-60 oil. Independent testing of the transmission oil samples was sub-contracted out to CTC Analytical Services. The test series went as follows:
<1> Spectrographic analysis indicated that it is has full synthetic composition.
<2> After 2 hours of operation, approximately 100 miles, oil sample analysis tests indicated that the viscosity rating was reduced from 60 down to a 43 level. No need to worry, this is a normal occurrence for this heavier type of oil. I attribute this to microscopic-level lubricant-strand trimming through operational loading where all of the oil contents has been passed through gear pressure-loading regions at least a few times.
<3> At 200 miles, the viscosity level stabilized at a 42 level viscosity since the 100 mile oil analysis test results.
<4> At 5000 miles, the oil analysis test results indicated a 40 level viscosity.
The test-transmission was completely disassembled and checked for wear. There were no signs of carbon film like experienced with the factory-fill oil. The phosphor-bronze lined synchronizers had no glazing and experienced an average mass loss of approximately 4% based on reserve-wear-range mass equivalency between 0.062"(new) and 0.048"(spent)
gap wear/mass measurements.
<5> At 10,000 miles, the oil analysis test results indicated a 39 level viscosity.
<6> At 12,500 miles, the oil analysis test results indicated a 37 level viscosity.
<7> At 15,000 miles, the oil analysis test results indicated a 34 level viscosity.
The test-transmission was again completely disassembled and checked for wear. There were no signs of carbon film like experienced with the factory-fill 30 oil. The phosphor-bronze lined synchronizers had no glazing and experienced an average mass loss of approximately 17% based on reserve-wear-range mass equivalency between 0.062"(new) and 0.048"(spent) gap wear/mass measurements.
<8> At 15,000 miles the oil had enough phosphor-bronze particles suspended
in it that deposits began building up inside of the synchronizer sliding
sleeves from the normal centrifuge-like rotational occurrence.
In Conclusion, until someone invents a copper magnet, we recommend that the ZF S6-40 6-speed transmission oil be changed at 10,000 - 12,000 mile intervals so as to minimize the amount of deposits of the suspended spent synchronizer material from collecting in critical component contact surface areas.
___________________

Per Bill's recommendation, I change it every-other season or 10,000 miles, whichever occurs first. I had no further issues with my 95 LT1 car after that (3 years, and about 15,000 miles), and in 7 years and 20,000 miles with my 90 ZF, behind 500+ hp/440 ft# of crank torque in the past 4 years using the TWS.

Paul.

DGXR

I have used the Pennzoil Synchromesh MTF in both my ZF6 Corvettes without any problems. It is not synthetic and I would not expect it to perform as well as the Amsoil or Red Line blue shockproof (or whatever it is called), but I only drive the car about 5000 (mostly easy) miles per year and it gets changed every other year, so the trans oil never has a chance to get anywhere near 15000 miles. I'll probably try the Amsoil at some point but it's not a high priority. As WVZR-1 said, regular changes are the most important thing... keep those fluids fresh.

wingnut96lt4

I used the AMSOIL and bought a 17mm socket . had to use a 1/2 breaker bar to get the plug out. So far it shifts smooth the oil in it was a little thicker,maybe this is the right thing.

dizwiz24

this is outdated, bogus info from almost 20 years ago.

Who knows if the castrol tws bmw crap stuff is still even the same formulation anymore?

Bill is spot on some stuff and dead nuts wrong on others.

This is a place where he is dead nuts wrong.

Again, its possible at one time castrol made a 10w60 tws product that worked for both bmw engines and zf transmission.

I can assure you whatever castrol they are selling at the bmw dealer (as of 2006 when i tried it and had my issues) doesnt work well in the zf6.