Front Axle U-Joint & CV Axle Replacement — 4WD Trucks
How to replace front axle U-joints and CV (constant velocity) axle shafts on 4WD trucks. Covers IFS (independent front suspension) and solid front axle designs.
Tools Needed
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Instructions
Diagnose U-Joint & CV Axle Failure
U-joint failure symptoms: clunking or clicking on acceleration or deceleration, vibration at specific speeds, squeaking from the front axle area. CV axle failure symptoms: clicking or popping sound that increases when turning (especially tight turns), vibration at highway speed (inner CV failure). Inspect the CV boot — if it's torn and has flung grease everywhere, the CV joint is contaminated and the axle should be replaced. A torn boot with no noise yet means the axle can sometimes be saved with a boot kit if done immediately. If the boot has been torn for more than a few weeks, replace the entire axle.
Remove the Front Wheel & Hub
Loosen the axle nut (large center nut on the hub) BEFORE lifting the truck — it requires significant torque to break loose (often 150–200+ ft-lbs). An impact gun works best. Lift and support the truck. Remove the wheel. Remove the brake caliper and hang it without letting it hang on the brake line. Remove the rotor. Remove the ABS sensor. Remove the hub/bearing assembly bolts (usually 3–4 bolts on the back of the knuckle). Pull the hub/bearing assembly off — you may need a few hammer taps.
Remove the CV Axle Shaft (IFS Trucks)
With the hub removed, the outer end of the CV axle is accessible. Pull the knuckle outward to give the axle room. Use a CV axle puller or insert a pry bar between the inner CV joint and the differential housing and pry outward firmly — the inner CV joint snaps into the differential with a spring clip. It takes a firm pop to release. Once the inner end is free, slide the entire axle out. On trucks with an axle disconnect (CAD/IWE), the inner connection point is at the disconnect rather than the differential.
Solid Front Axle U-Joint Replacement (Dana 44/60)
On solid front axle trucks (older F-250, Jeep, older Dodge), the front axle shaft has U-joints inside the axle tube (not a CV axle). Remove the axle shaft by removing the diff cover and pushing the axle toward the diff to release the C-clip. Remove the U-joint snap rings (4 of them, one on each side of each cap). Press the U-joint out using a press or a vice and socket method: position a socket slightly smaller than the cap on one side, and a larger socket to catch the cap on the other side. Press or hammer until the cap moves into the larger socket. Repeat for all 4 caps. Clean the yoke bore, inspect for damage, and press in the new U-joint.
Install New CV Axle or U-Joints
CV axle: slide the new axle through the knuckle and push the inner end firmly into the differential until the retaining clip snaps — you'll feel and hear a definite click. Pull outward on the axle to confirm it's locked in. Install the hub/bearing assembly. Thread on the new axle nut. Torque the axle nut to spec (typically 150–250 ft-lbs depending on truck) — this is critical. Reuse of old axle nuts is not recommended — they are typically a one-time-use design. U-joints: once pressed in, install all 4 snap rings. Make sure snap rings fully seat in their grooves. A snap ring that isn't fully seated will allow the U-joint to come apart at speed — catastrophic failure.
Reassemble & Test
Reinstall the rotor, caliper (torque bracket bolts to spec), ABS sensor, and wheel. Lower the truck. Torque the axle nut to final spec. Reinstall the wheel and torque lugs. Test drive: listen for the clicking or clunking that was present before. Tight turns at low speed should be quiet (no CV clicking). Acceleration should be smooth (no U-joint clunk). If a vibration is present at highway speed after the repair, check that the CV axle was fully seated at the inner end and that the hub nut was fully torqued.
