Those nasty little paper friction washers...

[Jools]

For a Procat diff. Is there any alternative to these paper friction discs? I would have every sort of paper up here so I could easily make my own. I've seen reference to using 1000 grade sandpaper, but I'm not mad about the idea of doing this... Surely if the diff runs a little loose the sandpaper would just devour the plastic washer carrier quick-smart (or maybe I misunderstand the mechanical arrangement)

I've finally (after a couple of years) got back to trying to finish my bitza Procat. (Don't ask!!!)
I'm in need finding an outlet for the steering arm/bush components, and the rear diff housings too. (Don't )
-Jools

[LurkingCAT]

You will be fine with 1000 grade sandpaper maybe even better with 600. If the diff is loose the main problem will be heat and meltdown of washer carrier, not the grinding effect from the paper. Just make sure to use a new lock nut and disc springs and tighten (and again) the diff properly...

[Jools]

Okay mate I'll give that a try, thanks. I have a complete new 'axle' assembly with new disc washers and thrust race... we'll see if I can get it adjusted right.
-Jools

[DerbyDan]

I'm still running this set-up in the front diff of my ProCat - albeit with an MMS pulley - I used 240 grit wet & dry paper... since this is the same stuff I use to hone in the plates themselves, I simply use a few small drops of super glue on the back face of each washer & stick them down to the back of the paper - then (once the glue has set) on a flat cutting board I cut round the washers using a scalpel & the washer as a guide.

[Jools]

Thx Dan. -Another thing re: the plastic Washer Carriers, I have x2 pairs, but they are 2 different lengths, one pair measures 8.8mm in o/a length, the other pair is 8.25mm o/a length.
Pretty sure they are all Schumacher parts, any idea which are the correct ones to use for the front diff? (My Procat came as a box of bits!).

[LurkingCAT]

The 8.25mm and 8.8mm are two different versions of the same parts number (T118).

The first version is the 8.8mm and was ment to be glued to the washer.

The 8.25mm is ment for friction paper, and is the evolution of the 8.8mm.

8.25 for Procat front and rear, but they'll both work fine.

[Jools]

Mystery solved, thanks mate.
Next question: What's with the hexagonal washer and carrier? There's no reference to this in the Procat manual, I split my rear diff and found it has the hexagonal type in there.
(Nice to finally have this Procat nearly complete - only taken a couple of years tracking down the parts and getting it together!), I have a really nice period Astro 05 Cobalt motor that could go nicely in it.

[LurkingCAT]

So only "pro" and no "problem" with the friction paper in the rear The hex carriers came in different versions - upgraded Schumacher and optional third party, aluminium and plastic.

[Jools]

Well I dunno if I could call it 'Pro', -more Am than pro!, but she's a runner! Great!
Bit of fiddling to get the front belt tension running centrally around the front pulley, that's good now but something is not right yet, maybe an alignment issue, because on the underside run the long belt runs way over to the left hand side where it exits (as viewed from above). Actually cuts into the exit 'slot' of the rear transmission cover. This was an existing fault I think because the belt had cut a 'slit' in there before I got the car.
I've checked that the eccentrics are matched ok, but maybe I need to compensate by rotating one or other side eccentric to change the angle of the rear pulley set.
Meanwhile I'll pull off the rear diff cover so I can see what's happening inside there, and I'll check tension of the short belts as well.
Anyway, good to see it throwing up a bit of Greendale dust at last. I'll put up a pic or two later.