Manufacturer specifications apply. This page explains concepts only. Torque values, clearances, preload, backlash ranges and procedures vary by axle model and must come from the vehicle or component manufacturer's service information. This directory does not publish repair specifications.
What this service covers
On 4WD pickups and SUVs with a solid front axle, the front axle shafts run inside the axle tubes from the differential to the steering knuckles. Each outer end usually has a U-joint or a CV-style joint so the wheel can steer while driven.
Shafts can twist, break or wear at the splines, and the joints at the knuckle wear with steering and off-road use.
Common signs
- Clunk or bind when turning in 4WD
- Vibration or grinding from the front when 4WD is engaged
- Gear oil leaking at the inner axle seals near the knuckle
- No drive to one front wheel in 4WD
What the work usually involves
- Diagnose whether the fault is the shaft, the outer joint, inner seals, the hub or the locking hub
- Remove the hub and knuckle components as the design requires
- Inspect splines and seal surfaces, install the shaft and new seals, and reassemble to specification
- Check 4WD engagement and road test
Steps vary by vehicle and component design. Values and procedures come from the manufacturer's service information.
Vehicles this applies to
4x4 pickups, Jeeps and SUVs with solid front axles; also some medium-duty trucks with driven front axles.
Key terms
Axle shaft spline
The machined teeth on the end of an axle shaft that engage the differential side gear (and, on full-floating axles, the hub drive flange). Spline count and diameter must match the mating part exactly; worn or twisted splines are a reason to replace the shaft.
Axle housing
The structural center section and tubes that enclose the differential and axle shafts and provide mounting points for suspension and brakes. A bent or cracked housing can cause misalignment, abnormal tire and bearing wear, and leaks.
Choosing a shop
- Confirm the shop works on your vehicle class and, for trucks, your axle make.
- Ask what parts they install (new, remanufactured or rebuilt) and what warranty applies.
- Check the listing's verification status and date in this directory.