zf gearbox fluid/oil

Hi
When i was at the Sema Show and talked with the RBT people they said that i should use the Castrol TAF-X .
That is also a synthetic oil.

In my 15 years of ownership I've seen this discussed many, many times. A few years ago I had Lloyd go through my ZF while changing to a higher fifth gear ratio.

I utilized our face to face time with a probing discussion about lubricant for a Pantera ZF. What I took away from the discussion was it really makes no difference what quality, properly-rated oil you use.

AND...

You will be changing the oil regularly every year.

Condensation within the ZF due to minimal usage and failure to fully warm the ZF oil on long drives to burn off such condensation, is the main issue to oil maintenance.

In a nutshell choose any oil that suits your fancy and then change it all out 12 months later and your ZF will not exhibit any oil related issues.

To answer the question you posed regarding mixing the trapped oil with a new or different oil the issue is a non-issue. Mixing the trapped oil with a synthetic oil has no ill affects.

One issue you've probably noticed in your readings is the ZF needs to have some miles put on it to fully distribute the oil after which you should recheck at the fill plug for proper final oil level.

If you're happy with the performance of the oil you choose this time around then you can just repeat that same brand, or try something new to see if it offers better performance for your needs.

Again, you're going to be changing it every year anyhow, right?

Larry

Same discussion over here...fully restored ZF by ZF Service Germany....all 5 ! synchs, also limited slip parts, ..all rosty..etc..
They recommended the "normal" oil obvioulsy Hypo, with LS support....
AND change it (standard action ..TX Larry to remind)..the synch rings and the LS disks have some surface metal "blend" which starts rosting (molybdenium XXX - which makes the surface suck up oil, so it provides the "resitance" to support shit to speed up the other gear during shifting)
I use Castrol 80W 90 LS is a GL 4 Oil. (Hypo)

@ Larry TX for the filling procedure..!

Matthias

Thank you all for your input. I now feel comfortable with any option I choose. Because of the very hefty price tag on repairs I wanted to make sure I didn't do anything stupid...

Rodman, too little gearbox lube is the only problem. Too much lube will vent the excess through the top vent and make a fearful mess but the box will still be OK. This happened to one owner who misunderstood the difference between liters and pints.... After draining (use a 17mm VW allen wrench on the side plug), it will take at least three separate fillings with an hour or more between topping-offs to properly add enough lube.

DO Not run exotic oil in your ZF, just the regular 80 90 gear oil is best. Lucas, and all the other specialized 0il just make your trany hard to shift. Do not run synthetic oil it tends to leak past seals not designed for synthetic oil
I have had my car for 20+ years, I know Loyd personalty and he insists on only 80 90 like O Reilly's brand. My ZF had to be fixed after over 100,000 miles, that's not bad for hard driving and 500+ horsepower.