HPI Baja Front Upper Arm Nylon Socket Ball Ends BJ054/BE by GPM  [BJ054/BE]

Front upper arm ball end upgrade

The BJ054/BE ball ends are aftermarket replacements for the front upper arm on HPI Baja machines. A nylon outer socket works with a hardened steel ball to give a low-friction joint between the alloy upper arm and steering or linkage hardware.

These scale parts are made to enhance durability and predictable movement rather than alter suspension geometry. Fit them when OEM ball ends show signs of wear or play, or during routine servicing to recover accurate steering and steady suspension travel.

Fitting is simple: remove the old ball end from the linkage or arm, push the new nylon socket onto the mating post and confirm the steel ball turns freely in the socket. After fitting check for unwanted binding or axial play and recheck after an initial run to ensure correct seating.

Tuning guidance: nylon housings typically allow smoother articulation than brittle plastics while steel balls resist surface degradation. If lateral play appears at the joint, replace the ball end rather than tightening linkages, since additional preload can introduce binding and change suspension response.