How much of an issue is the stock plastic caps popping off? I heard other people say get the Traxxas aluminum caps for the ultra shocks. Is it worth it or stay with stock?
If you do alot of big jumps they might come off , when they do you can put them back on with new shock oil or order the aluminum caps . I hv one of the first rustys that came out in 1994 and i still hv the same plastic caps on it , But again I don't do alot of jumping .
1 Rusty VXL
it is worth it. get aluminum caps
I've had them pop off on smaller jumps too. Definitely worth the upgrade if yours are popping off. I'd wait to see if it's a problem for you but on the other hand, as far as upgrades go, the caps aren't too expensive and they look good.
One thing that will keep you popping stock plastic shock caps off is oil level. After the first time they pop off you have to refill it right? Fill it all the way to top and don't allow for the bladder (in the cap) to have room you'll blow them off on even smaller jumps. Why? Shock oil (like any other hydraulic fluid) can't be compressed. The bladder is there to allow fluid take up space inside the cap as the piston is forced up on a landing. The fluid can't just free flow though the piston so as it comes up so until all the fluid is moved through the piston it has to go somewhere. If you fill the shock full the upward pressure of the piston just keeps pushing up on the cap/bladder since the fluid can't be compressed. In other words your shock is acting like a syringe.
Fill your shocks just high enough that you can set the bladder on top and no oil dribbles out. Put the cap on tight. The stock shock caps can be over tightened and loosen up so you don't want to over do it.
Brushless 9cell/3s Street Rusty
I've owned trucks that never had a shock cap pop off and owned others that popped off on the first run. The real problem is that once a shock cap pops off once, it's gonna keep doing it because the threads have been compromised.