Vintage CAT overview? Rebuilding advice needed.
 

Hi

Recently having acquired 2 Cat XLS, I got more interested in reading up about this car, and what the differences are between this version, and later ones. Is there a page that lists the differences, history, etc? Google gave me little luck finding something, but maybe I didn't look in the right place

Wikipedia has a timeline see https://en.wikipedia.org/wiki/Schuma...acing_Products

The a few difference but the easiest one is the lower chassis:
SWB - Stick Pack (Grey Bumper no front diff)
XL - Same shape as SWb but 20mm longer
XLS - As per the XLS with more option parts included (Silver Wheels)
XL/XLS had a saddle pack option chassis (with 6 cutouts)
Procat - 7 holes for batterys
Bosscat - Lots of options chassis here but the back of the chassis isn't at right angles when it comes in from the batteries and black weave and carbon became an options

If you want Schumacher history one of the better sources is rc10talk which is vintage focused there loads of old articles etc. In addition Daniel had set up a vintage schumacher facebook page where you can ask questions.

Keep meaning todo a post on this with more of the difference that people can help me refine. There lots of Schumacher experts on here that no more than me!

Here you go Henk the rc10talk link

http://www.rc10talk.com/viewtopic.php?f=28&t=4767

Thanks for the pointers, but I can only see a few listings, with a few keywords added to each car listed. No summary of version differences, parts compatibility and more in-depth info.The post Yachty made comes more in the direction of what I am looking for, but I would still like to see more detail. Like there must be more difference between the ProCat and the XLS than an extra hole in the chassis, for instance? And I noticed differences between the wheel hubs on cars that are listed online as CAT XLS, so either older parts were replaced by those of next gen models, or there were more batches of the same car, with production changes being cut in during a model's availability.

With the Optima Mid I know most of the version differences after wrenching on it, and reading up around the internet, chatting with guys with more or different experience, etc. I have zero history with the CAT, so I have some catching up to do.


Btw, Peakey, did you find those darker colored front shocks yet, to match the rears on my XLS?

Differences between the original CAT, CAT XL and XLS.

Original CAT
Short wheelbase
Rear differential built into layshaft, like the RC10 6 gear gearbox
Integrator unit where the rear diff should be, to adjust drive to front
Solid front pulley with one ways built into driveshafts
Stick pack battery mounting
Bent grey kydex front bumper

Changes between CAT and XL
Long wheelbase
New moulded bumper

Changes between XL and XLS
Front ball diff
Wider front and rear suspension using spacers and new rear fibreglass upper brace
New front shock mounts giving greater castor angle and kick up for front suspension

Changes between XLS and Procat.
New front bumper with holes for adjusting tensioner
New front gearbox moulding with built in belt tensioner
New front diff pulley that holds 14 balls instead of 9 balls
New wider saddle pack chassis
New fixed layshaft with new spur gear held on with o-ring. XLS layshaft contained rear ball diff
New rear diff with solid pulley to replace front drive integrator
New moulded plastic rear shock tower and wing mount
New rear suspension taken from the Topcat/Cougar

All the parts were interchangeable between models, for example it was quite common to update earlier cars with the Procat rear suspension if you had already upgraded the transmission with MMS parts instead of buying a whole new kit, and Schumacher updated some parts so the mouldings in the kits changed over time while keeping the same part number.


While the Bosscat looks similar it was a complete redesign sharing very few parts with its predecessors, only small detail parts were shared with earlier cars, with new chassis and transmission moving the belt above the chassis, new front and rear suspension, shocks and bigger 2.2" wheels.
While quite different some of the parts were interchangeable with earlier models, so again you could upgrade suspension parts on earlier cars with Bosscat ones.

Not yet Henk I'll look later and get back to you

All the above is on RC10talk but half the joy is learning from old magazine article etc. as there so many none standard tweaks. All the manuals are readily available online. PM me if you struggle finding them, If your XLS has been used a lot at club level it will be full of upgraded bits of later cars as back then upgrading was a common thing. Almost everything from origional CAT upto the PROcat fit each other.

The chassis just the easiest part to tell and if it is a Schumacher one the least likely to have been changed as the car is upgraded.

I have a batch of stainless steel fittings coming from model fixings so my restoration begin in earness.

I should be able to find some info in those car magazines that were up for download a while ago. It will be scattered though, even inside a magazine one story may be spread over 3 of 4 places inside the magazine.

I wonder, was it also popular to replace those flathead screws with Philips or hex? It makes wrenching a lot easier, but I would like to be sure replacement screws have the same thread, so I won't be stripping the holes.

In addition to my question about replacing the screws, is there any benefit of having the diff in the rear pulley system, instead of having the integrator there and ball diff on the layshaft? Which setup would work best for a casual runner? Is there much difference in transmission noises between the original 32p spur and a 48dp one?

I suspect the reason for changing the rear suspension to TopCat/Cougar setup is that the original setup is more prone to slop, with those pivot balls and extra tie rod to adjust rear toe-in?

I got a few answers already by searching, and through PM, but would still appreciate some extra info, besides answers to the several questions I posted.

Personally I stick to the kit specs except move to stainless steel for everything as I like the period look on vintage. Back in the day and as can be seen on modern cars I moved over to hex heads for the reasons you said about conventional screw heads.

Here are the sheets that came with the diff if these help answer your question

http://i1113.photobucket.com/albums/...psea1bcc33.jpg

http://i1113.photobucket.com/albums/...ps8f6f229b.jpg

Thanks for the MMS manual.

As for the screws, I'll stick to stock, or maybe replace a few one, should I have some missing ones.

Another thing, the car that I want to turn into a runner, had lots of lateral play on the front diff. I took it apart, and found a different diff is used. Does someone recognize this diff and suggest what might be missing, causing the lateral play?

That's the standard diff with the later spec hex washer carriers isn't it??

If I look at the manual of the XLS, the front diff uses only 8 balls, and different oudrives. When I look at the ProCat manual, a diffenent diff is used, with more balls, but with friction paper between metal drive rings, and outdrives.


Edit: and does anyone recognize this tool?

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

Like jimbo said they help the when putting the UJ's on the diff out puts and driveshafts

I see. I'll keep it with the Cat spares then.

Any more insights on the diff, where it comes from, and how to solve the lateral play? I am leaning towards adding some washers between plastic disc-holder and the bearings, but maybe this diff was designed to be used in a different version front gear box?

There shouldn't be any play when it's assembled with the right thrust race and disc springs. I personaly would use the hex washers as they hold the diff rings better than the friction paper.

http://www.retromodelisme.com/scan_p...er-page-9.html

But there is play, about 2 mm, side to side. Transmission housings fit together well. If I use the stock front diff, there is no excessive play. One thing, the transmission housings of the ProCat, as shown on that manual are different from the older Cats, to accomodate the tensioning bar, so use a different mold. My Cats have the older transmission housing, maybe that will only work with the stock diff?

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?