Im having problems with my ball diff in my xray evo 2. ive rebuilt it a couple of times and its always been good, but just before the nationals i rebuilt it and it slipps really easily between the balls and the diff rings. any suggestions to what might be wrong with it would be greatly appreciatted.

when i rebuild them i give the diff rings and thrust washers a quick rub on some 1200 grit wet dry to get the grooves out of them, a little bit of grease, put it together exactley as the xray manual says and its all good.

ill probably put a rebuild kit in the diff but if anyone knows what could be wrong with it please reply.

I'm not sure what the diff screw screws into in the xray diff's, if it's a lug, then you've probabely stripped the lug that the diff screw screws into? I'm sure you could borrow/buy one from someone at the track. Otherwise the parts should be standard in an Xray diff re-build kit.

is it possible that the cone washers not in properly? if one was missing, or .. not the opposite way to the ones around it.. pressure on the diff balls would not be created

this is just an idea.. other than that.. i got nothing.. lol
Rob Storey


second thought.. spring washers dead? ie.. been retensioned too may times.. forcing them to lose their spring-i-ness??

ive rebuilt the diff several times, the cone washers are fine, and the plastic nut the diff bolt screws into isnt stripped and it cant strip (another excellent design by xray), im just going to get a brand new complete diff and put carbide diff balls in it.

at castle hill on friday it was slipping bad due to the torque of the hacker 6turn brushless, i put the locked diff in and all it wanted to do was donuts, it was bloody hard to drive.

it would sound as if the support bearings in the centre of the diff halves ( one inside the diff pulley) are not seated completely in, thus not allowing the halves to clamp against the balls enough regardless of how much you tension them. Check that the one inside the diff halve is completely seated in.

is it possible that after rubbing back the diff rings enough that the support bearings are locking up on each other instead of the rings on the balls?

I really doubt that you'd buffed back that much on the diff rings, but if the initial thought by most people of the thrust unit failing. Would either cause the diff to spin apart and have zero grab, or be completely locked. But your problem sounds aas though its consistently slipping. If so, my only logical explanation at this time is that the halves are not clamping effectively. Most probably by the two support bearings. Those bearings should never be subjected to laterall loading, hence the fact that they are ball bearings not thrust type. They are there to give the halves and the pulley something to rotate on. Check them out. It might be a bit hard to remove the bearing in the diff halve though.