quote:Originally posted by David_Nunn:
Brad Penn makes a gear oil that sounds like it's perfect for our transaxles. It's called "Multi-Purpose 'Classic' GL-4 SAE 80W-90 Gear Oil". Here's the description: The SAE 80W-90 is specially blended using high quality PENN-GRADE® mineral base stocks and select additive technologies. It is designed to be used with “yellow” metallurgy (brass, bronze, copper) and other ‘soft’ metals used in synchronizers, bushings, thrust washers and other components typically found in classic manual transmissions and transaxles. In applications specifying API GL-4 quality lubricants, use of API GL-5 lubricants with higher extreme pressure additive activity/concentration can damage these ‘soft’ metal components.
That being said, POCA President Les Gray says he's tried them all and Redline 75W90 NS (synthetic) is the best he's ever used in a ZF.
I agree with the synthetic. I would add that the Mobil1 is excellent as well.
The ZF isn't particularly susceptible to developing leaks through the gaskets associated with using full synthetics at all.
The flat gaskets are cork which really is the issue right there. Cork shrinks.
The rear cover has the tendency to want to drip through the stud holes. Sometimes the only way to fix that is to put o-rings on the studs under the nuts.
Other then that it is really problem free.
I would add that the Redline for some strange reason seems to tighten up the feel of the gearbox itself.
It does that in every manual transmission I have tried it in and it does it to every box.
It makes it feel like a new transmission. Tight and precise.
Alchemy I tell you!
