Cat Sx diff giving me HELL
 

Hi people

Just got the Cat up and running after waiting for all the parts, electrics etc. Striped and cleaned the both Diffs before running. Ran it in the house just to see if the Diffs and slipper are loose, very small area, only big enough for half throttle and brake, they were loose.Tightened the front and rear Diff perfect and the slipper. Tried it again and there was a rubbing noise/diff sliping sound. Thought it was the slipper. Had a look at the car and the front diff was just sliping, no Diff action at all. One minute is was fine then there was nothing, no Diff action on the front. The rear was perfect.

The only thing i hate about the Cat Sx are the Diffs. Have taken them apart so many times, follow the manual correctly and they still give me hell.

People please help :cry:

Cheers
Chris B

did you back of the grub screw before adjusting the main diff screw, and did you re tighten it after? mine run for months at a time no worries,

Yeah did that. The rear Diff is fine, tried to tighten the front Diff, loosened the Grub screw as normal tightened the hex screw and did the grub screw up. Was fine for a bit, then just went loose,bolt was tight and grub screw. no diff action at all.

has the center screw snapped, i had that happen once or twice,turned out to be a faulty diff half, replaced that job done,

No screw or grub screw broken. Took male and female parts apart, Diff balls were ok, looks like no wear, lots of diff lube still in the Diff, put some more in anyway. Tighten the Diff and placed in back in the cat, checked grub screw and screw were tight and wasnt sliping. Tyred it again and it seems fine :confused: no sliping or anything, it is now a diff. So strange

Am racing tomorrow so will find out if the diff stays that way :thumbsup:

Will let you people know

next time its apart just check the washers between the bearings in the center of the diff are in the right positions, something must have slipped and popped back in place in the rebuild,?

Have no idea mate. Like i say, i have always had problems with the cat Diffs. I am sure the washers are the right way round, checked about 800 times when refitting and rebuilding :thumbsup: :thumbsup:.
Hopefully its fine now, will find out tomorrow

good luck

Cheers mate

Racing on a small ish carpet track :thumbsup:

See how the Cat goes

Ran the Cat today on carpet. I Cat was brilliant to drive. :thumbsup: So easy :thumbsup:. Great over the jumps aswell. The front Diff didnt give me any problems all day, so must be fixed :thumbsup:

I have just found this after Petit, just order a new diff screw. Are you saying the diff cup needs to be changed too?

if when u build it it has one tight spot there is a chance you may need to change the diff half the holds the diff screw, or clean it out, dirt gets in there

OK thanks, will check when the replacment diff screw arrives. Got a spare diff half in the spares I think that I share with a friend.

I've had the circlip that retains the thrust race come partially out. The symptoms were as follows... Diff started slipping, tightend it, still slipping, tried a bit more, still slipping (diff action was rubbish at this point) a little bit tighter and it seemed to stop slipping, but diff action was really tight. When I had chance to take it appart, that's when I found the problem. It appeared that the circlip had been compressed too much to slip it inside the outdrive and therefore it didn't seat very well in the intended groove. When I rebuilt it properly, all was smooth, but the head soon popped off the diff screw... A couple of races maybe.

It's the head that's popped off mine.

What tweezers do people recommend? Schumacher must sell a pair for the job?

On the Schumacher site hw010

Thanks Mike

I was racing at Bister Proline arena. The Cat went lifeless, nothing when i hit the power. Took the Cat of the track and the front diff went again. Took the front apart to get to the Diff and it fell apart. The head of the screw had broken off again, easy fix but lost the race :cry:.

Some people have not had any problems with the Cat Diffs but i have had my fair share of problems :(

Think I will order up a spare diff screw or even a complete diff as I am sticking with the Cat

Guy I was pitting with on Sunday had similar diff issues, he must have rebuilt it half a dozen times.

It had a stiff spot, we suspected a bent screw, but maybe diff half as you suggest. It got better after a jolly good clean out of the thrust end.

I presume the diff screw and grub screw both get threadlocked in?

The other guy I was pitting with didn't even realise there was a grub screw in there. The perils of buying a pre-built kit?

(Names intentionally left out...)