Tm2 v1 ball diff issues

[Gavin Collingwood]

Right guys I'm having issues with my ball diff. The diff needs to be tightened very tight to stop it slipping (too tight really) and because of this the diff it's self is getting very hot! Which in turn drains it of any diff lube and goes very gritty.... Something isn't right....? I've put new balls and plates in it too but it makes no difference?.... Can anyone help? Really want to try the ball diff as the car does feels more smooth than with the gear diff

[Legacy555]

Two things I had to do:
1. Remove flashing from the gear around the ball holes.
2. Shim the diff rings out as the 3/32 balls can be slightly small.

Heat can be caused by the out drives grinding on the polyarimid gear....

[super__dan]

Running a tight ball diff wouldn't inherently make it run hot, if anything, less rotation would make it run cooler IMHO.

[Gavin Collingwood]

Originally Posted by super__dan

Running a tight ball diff wouldn't inherently make it run hot, if anything, less rotation would make it run cooler IMHO.

Yes but It would bark if ran looser, I presumed the heat was coming from the plates rubbing on the gear... These balls are very small.... Would running slightly bigger balls say 2.5 work?

[Gavin Collingwood]

Originally Posted by Legacy555

Two things I had to do:
1. Remove flashing from the gear around the ball holes.
2. Shim the diff rings out as the 3/32 balls can be slightly small.

Heat can be caused by the out drives grinding on the polyarimid gear....

What flashing is that?

[Legacy555]

The beige polyarimid gear sometimes has some flashing on it from the moulding process. Just make sure its smooth - use a knife/file/dremel to make sure there is no high points around where the balls go.

[Legacy555]

Originally Posted by super__dan

Running a tight ball diff wouldn't inherently make it run hot, if anything, less rotation would make it run cooler IMHO.

Hi Dan,

I agree with you, however often the problem with this diff is that it is fully tightened down so that the outdrives and gear are in contact, but there rings are not fully in contact with the balls on both sides.

So the diff screw is locked down, but the diff still slips.... and generates loads of heat....

[Gavin Collingwood]

Originally Posted by Legacy555

The beige polyarimid gear sometimes has some flashing on it from the moulding process. Just make sure its smooth - use a knife/file/dremel to make sure there is no high points around where the balls go.

The diff I'm using uses a metal gear?....

[Legacy555]

Originally Posted by Gavin Collingwood

The diff I'm using uses a metal gear?....

Team C don't have a metal ball diff gear available....
It could be a Caster gear which also fits...... I have no experience of these although have heard that they are tough on diff balls which could lead to your problems.....

[Adam F]

The only way I managed to get the ball diff to work was with carbide balls and eventually bfast plates as the kit ones need to be replaced quite frequently..

[Clive Loynes]

I had to shorten the 5mm dia shaft that the bearings run on and also open up the bore to stop things rubbing that shouldn't have.

Then I fitted a gear diff and was in 7th heaven!

[Gavin Collingwood]

Originally Posted by Clive Loynes

I had to shorten the 5mm dia shaft that the bearings run on and also open up the bore to stop things rubbing that shouldn't have.

Then I fitted a gear diff and was in 7th heaven!

Open up the bore of what?

[Clive Loynes]

Originally Posted by Gavin Collingwood

Open up the bore of what?

The wee holes through the middle that the M2.5 screw goes through. It was rubbing on the screw and causing it to come undone.

The seating for the thrust race wasn't true either and I had to make a little spherical seating for the race to sit on to stop the screw head from failing due to fatigue.