[Arct1k]

Here is what RPM said

Dear Chris,
Since the problem is primarily tied to the front axles, most likely there is a set-up problem. There are a couple of things you need to look at. First, have you made any steering modifications to the truck? There is a very popular steering mod where the steering stops of the bell crank are removed, if you did this mod, there lies your problem. The square holes that allow the pillow balls to exit the RPM axle carrier are smaller than the stock holes. That steering mod causes those holes to stretch, causing the pillow balls to pop out. You can fix this by replacing the bell crank with a new one or if you have a high-end transmitter, adjust the end points to reduce some of the steering throw. Next thing to look into (and this applies to both front and rear carriers), if you threaded the pillow balls too far into the a-arms, there is the possibility that the axle carrier is hitting the a-arm when you turn the wheels. That causes extra force on the axle carrier which could also cause the pillow balls to pop out. One last thing to check, if you over-tightened your pillow ball setscrews, you are applying extra stress on the pillow ball mount inside the axle carrier. This too can cause the pillow balls to pop out. Thread the setscrews in until you just start to feel a bind in the pillow balls, then back the setscrews out 1/8 of a turn. I hope this helps.
Since this is most likely a set-up issue and not a problem with the RPM parts, if you would like a new set of carriers, we can sell those to you directly through us. Please send in $5.00 for each carrier you need, plus an additional $1.00 to cover postage in cash or a money order to:

Richard Royall
14978 Sierra Bonita Ln.
Chino, CA 91710