Outdrives cutting the dogbones
 

I had this issue with my B5m and it's happening again on my YZ-2 so I'm assuming it's to do with my "style" of driving. At some points around a carpet circuit the cars leaning aggressively onto the back wheel at full lock and the outdrives are scoring a line into the driveshafts. This eventually becomes a weak point and they will snap. I'm assuming it's happening on the last corner while entering the straight, probably putting the power down too early while still turning.

Is there anyway I can stop this without changing my driving? I assumed the design of the cars would prevent this tbh, is it possible I've something built incorrectly, or is this issue one of the reasons it's popular the raise the gearbox 2mm now?

Thanks if anyone can help

Some cars have this problem, and it (usually) happens when the suspension is fully compressed. I'd put an old O-ring over the shock shaft (on the outside, between the spring cup and shock body) to slightly limit your suspension travel. Using a soft material like an o-ring will also soften impacts when the shock bottoms out.

The problem of the driveshaft hitting the outdrive is not just wear: when there is enough force involved compressing your suspension (for example during a crash or impact), you can bend the driveshaft. It could also damage your outdrives and diff bearings.

That's interesting thanks for the reply. That makes me think it might be happening when I'm landing off jumps with the power down too, it can do weird things sometimes on landing. I tried using spacers on the outside on my old car and while it worked to protect the axles I didn't like the way it felt when the shocks bottomed out. Your o ring suggestion might work for me, I'll give it a try thanks.

Was at MB last night and tried running it with a 1mm spacer + an o ring on the outside of the rear shocks and it worked really well. When it was rolling in the corners the suspension was bottoming out but the o ring seemed to stop it from getting too snappy and unpredictable. I didn’t see anymore damage to the shafts but I liked the effect it seemed to have on the handling in mid speed corners so might try something similar on the front now too to balance it out thanks.

I’ve rebuilt the car this week and I think this may be happening when the suspension is fully compressed the wishbones can twist and continue to travel. There is also some play in the diff side to side. Limiters on the shocks seem to do the trick for now but also going to try graphite arms and shims on the diff