B4 Diff Problems
 

Hi,
I've recently rebuilt my B4's diff with new balls, slipper plates and thrust bolt. It seemed fine until last night when it began to make a bad clicking sound at 1 point in the rotation. Naturally, I whipped out the diff and had a look around. There didn't seem to be any problems other than very slight ware on the plates so I turned them over. The next race seemed fine but now it’s gone really slack and unpredictable. 1 minute it makes a bad scraping noise, the next its fine. In the same way, half the time the diff will engage when turning 1 wheel, and then it won’t...Does anyone know what might be to blame??? Thanks :)

New thrust bearing set also?

I had a clicking sound but I think its my old balls that are a bit knacked. As for the unpredictable diff, is it in the right way round? Diff screw head on the spur side?

Could well be the thrust race I reckon .

Yeah, could try that too...

Yeah, it is the right way around

Thrust race IMO...

Did you ever get to the bottom of this? I've had a similar persistent problem, turns out one of the balls was pitted:

http://lh6.ggpht.com/_2WuU54RBzc4/S7.../diff_ball.jpg

I can't see how this could have happened through running it, I think it must have been a manufacturing fault. It could feel perfect when I built it, then when the pit eventually lined up with the rotation of the ball, it would start clicking as the pit hit the rings.

Get yourself some B-Fast gear (balls, rings and thrust race). Just rebuilt mine with B-Fast stuff, now super smooth, much smoother than kit gear. I think the claim that ring flatness is critical is spot on.

I recently had some grit between the diff screw head and diff screw cover which caused a similar problem. Convinced I had to rebuild the diff, it was only when I removed the cover to get to the screw that I found this out.

Saved me the time and effort of a diff rebuild :D

Direct from US or UK distributor?

My diff started slipping tonight, tightened it but as rough as...

I am glad that you like them Anth. Thank you for the purchase and the complement.

Any order shipped, Direct from US for only $5us.

Fred