Differential Stuff

The differential in a ZF transaxle used in the Pantera is a 40% locking limited-slip differential that uses a friction and thrust washer plate at each end.  The friction plate rubs against the differential case and thrust washer when a torque unbalance occurs between each side in relation to the ring gear movement and the spider gear axles move up the triangular ramps in each differential case half.

Here's the differential.  You can clearly see the two differential case halves with triangular notches.  Also visible is the small axle dimpled thrust washer and the dog-eared thrust washer.

Another view of the dog-eared thrust washer.  The large dog-eared washer in the picture has seen some heat but isn't scored.  The smaller thrust washer is also worn but doesn't need to be replaced at this time.  The washer can be simply flipped over.

Here's the friction washer, indexed to the splined axle spider gear.  

The ZF manual calls for 0.1mm to 0.2mm of play in the system.  However, Lloyd B. and Dennis Q. both agree that you can run a little more play without problems.  I have 0.008", which is on the high side of 0.2mm.  No further work necessary, other than some good oiling of all parts before putting them back in the differential housing.  

There was some minor pitting of the spider gears but I'm told that pitting in these gears is common and isn't a source for worry.  The differential has been given a clean bill of health and ready to reassemble.

ZF Side Cover Breakdown

I've been busy doing other things lately, but I had a chance to get back on the ZF today.  I finally removed the pesky side cover axle seals.  It wasn't fun, and I worried about damaging something.  It required a good whack with a big hammer and a punch to move one side slightly and then I was able to pry it out with a handheld seal puller.

ZF Side and End Covers

The ZF side covers come out with some persuasion.  The manual calls for a special jig that removes the covers, but I found that a nice rubber hammer works just fine when you hit the cover tops.  To remove the stub axles from the bearings, you really need some good snap ring pliers and a press.  First, remove the small snap ring and washer below the snap ring.  I had to borrow a friend's snap ring pliers to remove them.