HPI RS4 EVO - Pinion gear
 

I'm new to the RS4 Evo. Purchased a used one. When I start it up the 1st gear pinion unscrews off of the clutch bell. Is the 1st gear spur one way bearing my problem?? It seems OK (ie only turns in one direction). Any ideas?

It's most likely not tight enuf.. try using some blue loctight and let it cure overnight.

well its probably your set screw. Tighten it up, its grip is alen so just get an alen key screw it tight ( the set screws right near the dog bone cup. ) hope this helps.

If its happening when you just start your engine, you are starting your engine backwards. If it happening when you try to drive, your 2 speed is going straight the 2nd gear and causing the 1st gear pinion to get spun off.

oh i thought u ment spur my bad....well take rapid roys advice..., and use a little thread lock not to much on the cb/pinion.

How do I keep my transmission from going straight to 2nd gear? I've tried tightening down the ball & spring as far as it will go???

If you have already done that, then somthing is binding up between the 1st and 2nd gears. Make sure that they spin independently of each other.

locktite, locktite, locktite,



Chances are the person who you got it from was trying out different gear combos and didn't have 'em set in for the long hual or didn't have a pinion gear tool...even HPI instructions for the pinions/clutchbell says to apply a SMALL AMOUNT of locktite to the cp pinions to keep them on. Good luck and enjoy! Those things are little tanks :-)