Monday, August 19, 2013

How to replace the right CV axle on a GM 1997 automatic transaxle Pontiac Grand Am

 The problem appeared as very strong vibration and noise coming from the right front of the car. It increased with speed. I raised the vehicle and put it on stands and had a helper run it. The right front wheel would sometimes actually stop while the left was turning. It had to be a bad right CV axle. This job is an intermediate job for the home mechanic. To get down to removing the bad axle, the front bearing and hub as well as the steering knuckle must be removed. A video of the job follows the text.
   I'm a die-hard home mechanic, not a professional. While I strive for accuracy and attention to detail in these procedures, I cannot guarantee that every step and description is flawless. If in doubt, consult a auto repair manual or the services of a professional mechanic. Above all, take your time and be safe.

The job at a glance

  •   Tools: Floor and/or scissors jack to lift the front off the ground.  Jack stands or railroad ties, lug wrench, 30mm deep well socket ½” drive,  3/8” allen socket, T55 socket, a set of chisels,  hammer, torque wrench, breaker bar, 18" pipe wrench, 15 and 18mm box end wrenches, 21mm socket and 1/2" drive ratchet, a large flat blade screwdriver, a small lug wrench.


  • Parts and materials: Rebuilt CV axle by National from Carquest Auto Parts for $49.95. (August 2013), Wire hanger, an M12 X 1.75 nut.


  • Savings: $150 average repair shop labor.


  •  Time: 3-5 labor hours for the home mechanic.


                                                                  Disassembly
1) Break the lug nuts on the wheel.
2) Jack up the front end. I used two jacks , a floor and scissors jack under these loaf-like projections on two arms angled outward from behind the wheels. Rest the front end on some stands. I used railroad ties.

Front end is jacked up and on railroad ties

3) Remove lug nuts and take off the plastic wheel cover, if equipped. Remove wheel.
4) Put wheel back on and hand tighten a couple of lug nuts.
5) Jack up high enough to set the wheel down on a paver or wood, without removing stands.
6) Break the axle nut loose with a 30mm deep well socket and breaker bar. This is highly torqued nut. I needed a 24” breaker bar and a more than a dozen all-out grunts.
Break out the big one. This axle nut is torqued. 
7) Set the car back down on the stout supports.
8) Remove the wheel.
9) Unbolt two caliper bolts with 3/8” Allen socket. Pry off caliper. May need to use large screwdriver wedged between caliper and rotor.
10) Use a wire to hang the caliper from a strut spring.
Hang the caliper from the spring with a piece of wire
11)  Remove the rotor and set aside.
12) Unbolt the 3 hub and bearing assembly bolts with T55 socket. Must turn the hub to align the bolt with large hole in the hub so that the long bolts can be removed.
Unbolting the hub/bearing assy with a T55 socket and 1/2" ratchet

13) Now we must break the hub/bearing assembly loose from the steering knuckle. This is the fun part.  I had success after a struggle, with three chisels, pounded in near each mounting hole between the hub assembly and the steering knuckle.  I started with a ½” Craftsman Chisel, then to 5/8 and finished with larger size. As a gap grew to 1/32” I  used an 18” pipe wrench, wide open to turn the hub assembly a few degrees one way and then the other. That was it and it came out of the knuckle.
I tried a striking a pry bar with a hammer, but chisels and a pipe wrench finally broke it loose


14) Unbolt the steering knuckle from the strut. Use 21mm socket and breaker bar on the nut and hold the other end with a 15mm wrench.

Unbolt the knuckle from the strut
15) Unplug the ABS speed sensor and secure out of the way. Use a towel or rag to protect the outer CV boot. Oh, no need, that's right it's bad.
16) The only thing now holding the steering knuckle is the lower control arm ball joint. To separate it, swivel the steering knuckle to the left and move the CV axle as far left as possible. Jam a pry bar in there to hold it out of the way. Now remove the cotter pin. Mine had a pin through it that was welded to the knuckle. Nice. I used a hammer and chisel to break it out. Turn the castle nut out with a 18 mm box-end wrench.
Take off the castle nut and put an M12 X 1.75 on the stud and hammer the knuckle loose

 17)  The repair books tell you to use a pickle fork to separate the ball joint from the knuckle. That will likely ruin the rubber boot and require a new ball joint.  Instead, spin an M12-1.75 nut (don’t use the castellated nut, it could be damaged by the hammer blows) on the ball joint stud until it is flush with the top of the stud. A few well placed blows to the nut/stud should break it loose. The steering knuckle can now be removed and the axle stands alone.
The knuckle is outta there with the lower ball joint intact.

18)  Remove the CV axle from the transaxle. It just needs to be lightly tapped out. I came in from under the front side and I was able to wedge a small (12”) lug wrench  between the inner casing of the CV axle and the end housing of the transaxle. I then tapped it from the rear with a hammer until it pulled out from the transaxle.
Carefully and lightly tap from the back on a short bar wedged between the axle and transaxle
There was no loss of fluid.  I took off the outer boot to examine the axle. The outer joint has too much free play, it’s slopped out.  I paid $49.95 for a National rebuild from Car Quest.


                                                                Installation
1) Apply a little wheel bearing grease to the transaxle where the CV axle will be inserted.
2) Protect the boots on the new axle with a shop towel. Insert it into the transaxle as far as possible. Tap it in the rest of the way with a hammer and a large screwdriver. Check the seat by pulling on the end of the inner joint where it faces the transaxle. Do NOT pull on the other end of the CV axle. It could come apart.
Using a ridge on the inner axle joint, tap the axle in till it won't go any further into the transaxle
3) Grease the outer end of the axle. If installing a new knuckle seal, this is the time. This seal is for the bearing and comes with a new bearing and hub assembly. It must be installed before the knuckle is bolted back on. If replacing only the bearing and hub assembly,  the knuckle would need to come off before this seal can be replaced. My car did not come with this seal and I did not install one.
4) This is a good time to clean up the mating surfaces of the steering knuckle with a wire brush, some sandpaper and then clean up with a solvent..
5) Mount the steering knuckle, first passing the end of the CV axle through the center opening. Then seat the bottom of the knuckle on the stud for the lower control arm ball joint.
6) Install the castellated nut back on the ball joint stud and torque to 40 ft lbs. Line up the stud hole with a castle opening. Install a new cotter pin.
7) With one hand to insert a knuckle to strut mounting bolt while pushing the knuckle downward until the holes align with the other hand. Torque them to 90 ft lbs.
8) Plug ABS speed sensor back in.
9) Mount the hub and bearing assembly. Torque the T55 bolts to 70 ft lbs.
10) This is a good time to go over the brakes for wear and at the least clean and put some fresh grease on the caliper pins.  If using the old rotor, put it in the very same position it was it when it came out. It helps to file off a bit of the outer raised ridge of the rotor so the brake pads will fit back over the rotor. Torque the caliper bolts with a 3/8” Allen socket.  If using a torque wrench it’s 38 ft lbs.
11) Mount the new axle nut and the old washer. This is big torque, 192 ft lbs. Check the wheel by turning it by hand while both are still off the ground. It should turn, but somewhat grudgingly. If it doesn’t, back off the axle nut a bit until the wheel can be turned.
12) I test drove the car on stands to make sure the right wheel turned freely with the left. Yes, it did and so quietly this time.
13) Road test drive the car. Happy and quiet motoring. Well done.

                                                                Here is a video:


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