Axle Components

Spindle nuts secure the wheel bearings on the axle spindle. Torque the inner nut to 50 ft-lbs while rotating the wheel, then back off 1/4 turn. Install the lock nut and cotter pin. Proper adjustment allows the wheel to spin freely with no side play.

Replace wheel seals whenever servicing bearings, if there's visible grease leakage, or if the seal is damaged during inspection. Seals prevent grease from escaping and dirt from entering. Always install new seals with the lip facing inward.

Bearing races should be installed with a race driver or appropriately sized socket. Tap evenly around the circumference, never in one spot. The race must be fully seated in the hub. Check for no gaps between the race and hub.

U-bolts should be torqued in a crisscross pattern to 75-90 ft-lbs for 3,500 lbs axles, 90-120 ft-lbs for 5,200-6,000 lbs axles, and 120-150 ft-lbs for 7,000+ lbs axles. Re-torque after first 50 miles and then annually.

Dust caps come in push-on (metal) and screw-on (plastic) types. Common sizes are 1.98", 2.44", and 2.72" diameter. Measure the outside diameter of your hub to determine size. Push-on caps are more common in heavy-duty applications.

Spring pin mounting uses tapered pins that press through the spring eye and hanger. Bolt mounting uses threaded bolts with nuts. Spring pins allow some flex movement, while bolts provide a more rigid connection.