How to Replace a Pinion Seal on a Chevy Truckby Christian Killian
Replacing the pinion seal on the rear axle of your Chevy truck will keep the gear oil in the differential and off the driveway. The gear oil in your truck’s differential not only lubricates the bearings, it also cools the gears and reduces wear on all the components inside the housing. If the pinion seal begins to leak, the fluid level can drop enough to damage those internal components and result in an expensive repair.
Raise the rear of your Chevy off the ground with a jack and position a set of jack stands under the axle housing. Lower the jack and allow the truck to settle onto the jack stands.
Locate the four retaining bolts on the pinion flange and remove them with a wrench. Pull the drive shaft back and remove the u-joint from the yoke then set the drive shaft aside.
Locate the large nut in the center of the pinion yoke and match mark it to the end of the pinion shaft with a paint marker. Place a torque wrench on the nut and note the force require to turn the nut. Remove the nut from the pinion shaft with a large breaker bar and socket, you will need to set the parking break securely to do this.
Slide the pinion yoke off the pinion shaft and set it aside. Using a small flat screwdriver, bend the outer metal ring of the seal to help loosen it then pry it out of the bore. Pack the cavity behind the seal with lithium grease then install the new seal into the bore.
Drive the seal into the bore with a seal driver and hammer than slide the yoke back onto the pinion shaft, making sure the marks you made on the yoke and shaft align. Install the pinion nut and tighten it, seating the yoke on the shaft.
Tighten the nut with a torque wrench, using the torque reading you took before removing the yoke as your guide. Position the u-joint on the drive shaft back in the yoke and install the retaining bolts. Tighten the bolts with a wrench.
Raise the rear of the truck off the jack stands with a jack, remove the stands from under the truck then lower it back to the ground.
Items you will need
- Jack stands
- Wrench set
- Paint marker
- Torque wrench
- Socket set
- Small, flat screwdriver
- Lithium grease
- Seal driver
- "Chevy Truck Factory Service Manual"; General Motors Corp.; 2004
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