K2XX 4x4 passenger's side front inner axle seal replacement procedure (better than GM's)

[SinisterZ71]

I wanted to start this thread and share what I've learned about replacing the front passenger's side inner axle seal on a 2017 Silverado K1500 (this is the seal behind the axle flange the passenger's side CV axle bolts to on the front differential).  The GM service manual states you have to pull the electric power steering assist motor off of the steering rack in order to perform this service which would then require you to reset the power steering belt tension using a special tool that I'm sure very few have (it uses a microphone to listen for a specific frequency the belt generates when tension is set correctly).  You do NOT need to remove the electric power steering assist motor from the rack in order to get the passenger's side extension housing off of the front differential.  Here's the procedure I came up with to do this job...

 

1. Raise the front of the vehicle and support with jack stands on the frame or by using a 2-post lift.  If the vehicle is on a 4-post, drive-on lift; it will be necessary to raise the right front tire off the lift (put a jack stand on the frame, not the control arm).

 

2. Remove the skid plate and skid plate mounting brackets that attach to bottom of the engine cradle.

 

3. Remove the top nut from the passenger's side sway bar end link (in order to disconnect the sway bar from the control arm).

 

4. Remove the sway bar to frame brackets (2 bolts on each side) so the sway bar is free from being mounted to the frame.  This is necessary to give clearance to remove the passenger's side lower control arm bolt facing the rear of the vehicle.

 

5. Remove the two shock mounting bolts on the front passenger's side lower control arm.

 

6. Remove the front passenger's side lower control arm to frame mounting nuts and bolts.  There are small conical washers under the nuts for these bolts and the conical side of the washers need to face the frame (not the nut) upon re-installation, so don't lose them.

 

7. Swing the lower control arm down from the frame (it can stay attached to the steering knuckle via the ball joint).  With the control arm disconnected from the frame, this will allow enough room to unbolt the passenger's side CV axle from the differential extension housing axle flange and swing it down out of the way.  Consequently, this same procedure can be used to remove/replace the CV axle without needing to separate ball joints form the steering knuckle.

 

8. Unbolt the passenger's side CV axle from the differential extension housing axle flange and swing it down out of the way.

 

9. Disconnect the 3 electrical connectors from the electric power steering assist motor and carefully remove their loom fasteners from the body of the steering motor so you can move these harness pigtals out of the way.  NOTE: there is a bare ground wire attaching one of these connector pigtails to the steering rack via a torx screw.  I did not need to remove this to give myself enough room to work, but doing so will make it easier.

 

10.  Disconnect the single harness connector to the front axle disconnect motor/solenoid and route it out of the way (I stuffed it between the engine's oil pan and cradle).

 

11. Use a jack to support the weight of the front differential.  Remove the two nuts holding the passenger's side front differential extension housing to the frame bracket.  Be very careful when removing the nut above the electrical power steering electrical plug so you do not damage this plug.

 

12. Remove the 5 bolts holding the passenger's side axle extension housing to the differential case.  It will be necessary to lower the jack supporting the front differential (so the extension housing will tilt down) so you can get to the top 2 bolts on the extension housing.

 

13. Place a drip pan under the front differential to passenger's side axle extension housing flange.  Use a hammer to tap the front passenger's side axle extension housing towards the passenger side of the vehicle to separate the extension housing from the main differential housing.  (There is a gasket between these parts.)

 

14. Once separated, a spring and washer may fall out - set these aside (the spring goes on the axle engagement fork shaft and the washer goes on the end of the axle shaft upon re-installation).

 

15. You should now be able to rotate and remove the passenger's side axle extension housing from the truck.  The axle engagement fork and collar may fall out of the axle extension housing so be ready to catch them if they do.

 

16. Place the extension housing on a clean bench with the CV axle mounting flange down.  Remove the axle engagement fork and collar if you haven't done so yet - this will expose a snap ring holding the axle in the housing.

 

17. You'll need a pair of snap ring pliers and a couple of small screwdrivers (and perhaps even a curved pick) in order to get the snap ring off.  It will be difficult.  Once the snap ring is removed, you can remove a tanged washer from under it in the housing and then pull the housing up off of the axle shaft.

 

18. With the axle shaft removed from the extension housing, you can now change out the end seal.  There is a small bearing down in the housing under this seal so take care not to damage it when removing the old seal.

 

I recommend applying Loctite High Strength Bearing Mount For Relaxed Fits on the exterior of the new seal prior to installing it into the housing.  The new seal I got from GM was not a tight fit, so I felt the loctite was necessary to properly secure the seal in place.

 

I will post reassembly instructions and torque specs later when I get more time to complete this thread.

 

 

[SinisterZ71]

Reassembly procedure...

 

A. Stand the inner axle shaft up on your bench with the hub end down.  Lubricate the area of the axle shaft where the seal and bearing ride with petroleum jelly or trans assembly goo.  Inside the axle extension housing, lubricate the roller bearing and new seal with petroleum jelly or transmission assembly goo and slide the extension housing down over the axle shaft.

 

B. Reinstall the tanged washer into the housing then install the snap ring (make sure the snap ring properly installs into the groove on the shaft.  (NOTE: GM recommends replacing this snap ring but I reused mine because nothing was wrong with it).

 

C. Insert the axle engagement collar into the axle engagement fork with the plunger end of the shaft pointing down (to go inside the extension housing) and hollow area of the collar facing up (towards differential).  Install these parts back onto the extension housing over the exposed axle shaft.

 

D. Coat one side of the thrust / end play washer mentioned in step 14 above with petroleum jelly or transmission assembly goo and place it onto the pilot shaft that's part of the axle shaft (the jelly/goo should hold it to the shaft so it doesn't fall off when you are trying to reassemble it).

 

E. Smear some petroleum jelly or transmission assembly goo onto one end of the spring from step 14 above and install that end of the spring over the axle engagement fork shaft.

 

F. Clean the gasket mating surface with brake cleaner and install the new extension housing to differential housing gasket - making sure to align the dowel pin holes properly.

 

G. Clean the gasket mating surface of the differential with brake cleaner.

 

H. When reinstalling the axle extension housing onto the differential, the spring on the axle engagement fork shaft must insert into the raised hole boss inside the differential housing which is forward (towards the front of the truck) of the main shaft in the differential.  Rotate the axle during installation to ensure nothing binds and make sure the gasket and extension housing engage the dowel pins correctly as you are putting it together.  The extension housing should go pretty much all the way on by hand, although the alignment dowel pins may provide some resistance requiring some pressure to get the extension housing to fully seat against the differential.

 

I. Apply some blue threadlocker to the threads of the 5 axle extension housing to differential bolts, install the bolts and hand tighten all - observing that the housing is going onto the differential evenly.  If not, remove the extension housing and make sure the thrust/end play washer hasn't fallen off the axle shaft pilot or the spring isn't binding and is going inside the raised boss / hole in the differential housing.  Torque the axle extension housing to differential bolts to 41 ft/lbs.

 

J. Jack up the differential so you can install the washer nuts that fasten it to the frame mount.  Torque these nuts to 75 ft/lbs.  Take care to not put any pressure on the plastic electrical plugs protruding from the electric power steering motor.

 

K. Reconnect all three electric power steering motor harness connectors and the single harness connector for the axle disconnect motor/solenoid.  Make sure you reinstall the harness holders into the provided bosses on the electric power steering motor housing.  If you broke these off during disassembly, it would be a good idea to zip-tie the wiring harness to the electric power steering motor housing so it doesn't rub on anything.

 

L. Reinstall the CV axle onto the inner axle hub.  Apply some red threadlocker to the six CV axle to inner axle flange bolts and install them all hand tight (do not torque them down at this time).

 

M. Reinstall the lower control arm into the frame.  The longer of the two bolts goes in the rear, and both bolts install from the rear.  The conical end of the washers for these bolts faces the frame on the side the nut installs onto.  Apply some red threadlocker to the exposed threads of these bolts and install the nuts onto the bolts by a few turns - DO NOT TIGHTEN these nuts at this time.

 

N. Coat the threads of the bolts that connect the shock to the control arm with blue threadlocker and install them.  Torque these bolts to 37 ft/lbs.

 

O. Coat the threads of the sway bar to frame bracket bolts with blue threadlocker.  Reinstall the sway bar to frame brackets and torque the bolts to 37 ft/lbs.

 

P. Reinstall the sway bar end link and torque its nut to 17 ft/lbs.

 

Q. Torque the CV axle to inner axle hub bolts to 58 ft/lbs using the star torque pattern.

 

R. Lower the vehicle completely and jounce the front suspension a few times so it settles into normal ride height.  Torque the front lower control arm to frame nuts to 129 ft/lbs. (NOTE: It is important for the lower control arm nuts/bolts to be loose until the suspension is settled into normal ride height before torquing - otherwise the control arm bushings could be over-twisted if you torqued these with the suspension unloaded).

 

S. Refill the front differential with 75w90 full synthetic gear lube.  Torque the fill plug to 24 ft/lbs.

 

T. Reinstall the skid plate brackets onto the engine cradle and then reinstall the skid plate.

 

At this point you can either raise the vehicle to get all 4 tires off the ground and test to make sure 4WD works or you can operate the vehicle on grass/dirt/gravel to verify proper 4WD operation.

 

If for some reason it doesn't seem like the front wheels are getting power sent to them in 4WD mode, discontinue driving and disassemble the front axle extension housing and inspect the axle thrust/end play washer and spring to make sure they are installed correctly.