My Procat rear diff is too narrow.
 

Either my Procat rear diff is the wrong type, of the eccentric housings are the wrong type, because the diff is too narrow to reach the eccentric housings. The eccentric housings barely reach the outer edges of the ball bearings, so the diff wil fall out of the eccentric housings on either side when it's assembled. Now, my eccentric housings are white, while the plastic on the rest of the car is black, so I wonder if I somehow got hold of the wrong housings back in the day. I had shimmed the diff with washers to make it sort of work, but this means the four prongs on each diff output are barely engaged.

Can someone measure their eccentric housings to let me veryfi mine? Mine are 6,5 mm thick in total.

My diff obviously isn't the same as the one in the manual, as I have the hex washers, so I'm not 100% sure it's complete. The picture shows the parts my diff is made up of. In addition to the puleys with balls, I have hex washers, hex carriers, bearing and shafts. Does it look right?


I have made myself some CNC-milled aluminium ecentric housings that I will try to use, but I'd love to have the Procat as original as possible.

If your eccentrics are white plastic, then they are Bosscat ones, and yes they are much narrower than the Procat ones. So sounds like that is the problem.

The kit plates and carriers were round, and you had to glue sandpaper to the back of the plates i think!! There was a revised part released that was a hex carrier and matching plate. I think they were white plastic, but can't remember for sure. The ones you show look like alloy? I don't remember if there was an alloy "hop up", possibly. Or they could be a different version, or my memory could be dodgy.

That explains it. I have a feeling the guy who sold it to me in the 80's had used lots of random spare parts he had lying around. I bought it from a high ranking local racer. It also has a wide Cat front bumper, a Cougar rear shock/wing mount, and a Cougar wing.

My home made alu housings worked perfectly and center the diff in the with no pre-load. If I paint them black, noone will know the difference. ;)

My diff plate carriers are made from aluminium. You can imagine my confusion when I took the diff apart to service it as a kid, and saw that the manual said to glue sandpaper to the washers. "What's the point?" I thought to myself.

Installed. These are 3 mm deeper than the Bosscat housings.

Why paint them ????

mvh Isobarik

U300 was the uppgrade alu hexdrive ...and yes there is an white version also but dont know the part number yet ........

mvh Isobarik

I won't paint them. Just a thought as I want the car to look original.