Devin

Today my pinion came loose and moved forward off the driveshaft three times. Each run was around five minutes.

The first time I added in some blue thread lock. I could see some residue from before, so I put another small drop on. I've tightened the nut as much as I can, and allen key is literally bending under the pressure, but the pinion is still coming away from the spur gear.

Is there a trick for getting these to stay on?

For reference the vehicle is an RC8.2e RS.

racer1812

iTrader: (31)

I'm guessing you're using a cheap L shaped allen wrench? You'll never get them tight enough with those. Invest in a quality wrench and you shouldn't need any loctite.

Bigwave

I assume you're lining up the flat spot on the shaft with the set screw? Had to ask.

huzzler

iTrader: (1)

+1 on this and put the loc tite on the set screw before you put it on the pinion. Should not have any problems with it coming off doing it this way.

RCaddict0

iTrader: (85)

Odd.. ive had a few come off here n there ofcourse. But never repaeted troubles. +1 on the screw driver, thread lock,etc.
Maybe a small dab of CA glue. Super glue and shoe goo are versitial tools

cdwilliams1

iTrader: (38)

Allen screw on the pinion may be stripped if you've been cranking on it. Especially with cheapo tools. Have you tried replacing the pinion and set screw altogether?

I had a stadium truck back in the day that would lose it's pinion every single race. Blue thread lock and super glue did nothing. Turned out the threading for the set screw was stripped.

racer1812

iTrader: (31)

If loctite works for you great, but in 20+ years I've never seen the need if everything is done correctly...

Bigwave

One other thing you can check is the bottom of the set screw. Make sure it's flat so there's a good surface pushing down. If it isn't use a dremel or something to flatten the bottom.

blis

I'd generally agree with that but on the Shepherd the thread tolerances were a little sloppy and grubs would work loose all the time.