Vintage CAT overview? Rebuilding advice needed.

[OptimaFan]

Originally Posted by DerbyDan

Do you mean the 'rocking' of the pulley as it moves about over the balls in the diff or a side to side play of the diff once mounting in the housing?

Side to side play when mounted in the housing. the bearings can slide side to side in the transmission housing, as if the bearings are too thin, or the housing too wide internally.

[purplenut]

Originally Posted by J1mbo

That's the tool to stop your hands from bleeding when you put the driveshafts together

Just love that answer...

[MattW]

The hex washer carriers were a later option I'm sure. I don't know if they ever came in kits.

As far as I know, the diffs were all inter changeable, and the housings - although different for the belt tensioner, were the same everywhere else.

[OptimaFan]

It would be interesting to see if a stock 8 ball diff will fit a ProCat transmission housing. If the ProCat housing is more narrow on the inside, the stock diff should be binding.

[DerbyDan]

The above image was recently posted up over on RC10Talk - this shows two different types of transmission halves - on the Left is a CAT housing (without the loop for the ProCat's tensioner bar) on the right is a ProCat housing with the 'loop' - as you can see different bearings are used... Ironically my ProCat uses a housing which uses the flanged bearing - but has the tension bar loop! However as far as I know, you can fit a later diff in an early housing & visa-versa.... I just wonder what bearings you are using??

I have just checked my car & there is pretty much zero 'float' for the diff between the housing halves

[OptimaFan]

I have the flanged bearings. Indeed oddly enough these are also shown on the ProCat manual, using the tension bar version transmission housing. With the current setup here there is so much float that the diff side almost touches the rectangular cutout on the top, and the sides of the diff plate holders rub against the inside of the transmission housing.

The bearings are intact, but I could check the thickness.

[Peakey]

See if it's the bearings Henk if not I'll have a look through my parts I might have a housing you can have if its that

[OptimaFan]

Originally Posted by Peakey

See if it's the bearings Henk if not I'll have a look through my parts I might have a housing you can have if its that

When back home, I'll get my caliphers ready, to check the bearings.

[OptimaFan]

Bearings are 12 x 8 x 3.5, thickness including flange. The flange is 0.8 mm and the total diameter including flange is 13.5 mm

[OptimaFan]

Any more ideas on the front diff issue?

[DerbyDan]

Have you got the two plastic washers fitted on the outside (Parts T080 on the exploded view on Peakey's link) between the diff output/driveshaft connection & the housing/bearing? - I must admit I thought the purpose for these was purely to stop dirt getting into the bearings but they might hold the diff central within the housing???

[OptimaFan]

The manual shows these washers on the outside of the bearings, as shield, which is the most logical position. Plus on the inside, the washers will rub against the side of the bearing. Wish I had a ProCat transmission housing to see if that is different. Else I may have to resort to shims, as I want to keep the stock 8 ball diff for the shelf car

[Peakey]

All I've got is the Procat housing Henk pm me your address again and I'll send it out to you

[OptimaFan]

Nice, thanks! PM sent. Maybe the mystery will soon be solved.

[joolstacho]

(Oooh I don't think this one will ever be solved!)
That (above) was my pic of the 2 trans types. Not only do we have the 2 housing types and 2 different bearing types, there are also 2 different T118 washer carrier types which are different lengths, which could affect assembled end-float. They also differ in the diameter of the washer ID recess because there are 2 different central boss diameters in the T173 diff pulley that they fit over.
(Had enough yet?)

[OptimaFan]

Thanks for the input. Maybe just replacing the transmission housing with the one that Peakey promised to send me, will already be enough. Considering that the ProCat manual still lists the flanged bearings, but does have the belt tensioner plate, there is a 3rd style diff housing, being a combination of the 2 on those pics. And if all else fails, I could always try some shims between flanged bearings and diffplates, to get float to acceptable levels.

[OptimaFan]

Something different, but yet related, I found some Schumacher bits that seemed helpfull for parts. I can't find out what car it used to be. No pics at the moment but it's 2WD, and motor before the rear axle, just like the XLS, etc. Another feature is that the cover for the left layshaft bearing is not square, like the 4WD Cats have, but triangular shape.


Edit: pictures added

[OptimaFan]

Turns out I didn't get a selection of Schumacher parts with this purchase, it's car that is largely "inspired" by the Cat series, a Robbe Geronimo. Originally 4WD, but somehow the front part of a Kyosho 2WD, possibly Ultima series, got bolted on, and to make the mashup even more complete, the clamps on the rear shocks are RC10, dyed pink.

[OptimaFan]

A question for the Cat experts. I now have both the regular XLS front transmission housing, as well as the Pro Cat version (thanks, Peakey!), with the tension bar. Both use the flanged bearings, and both have the same extra play with the new style diff. So in both cases I'll have to use shims to reduce side to side play, no difference there. But does using the Pro Cat housing make adjusting the belt tension indeed easier, or not? If it does, I'll keep the stock XLS version for the shelf car, and install the Pro Cat version in the runner.

[Peakey]

The Procat box will help tension the belt a lot easier where as the xls you need to just clamp the front box.
With the Procat box you add the tension to the rear belts then tension the main belt with the tension bar then clamp the front box.