FAQ: CV Boot Replacement Procedure / Half-Axle Rebuilding

General E28 FAQs.
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528elover
Posts: 656
Joined: Sep 18, 2010 11:14 PM
Location: Tucson, Arizona

FAQ: CV Boot Replacement Procedure / Half-Axle Rebuilding

Post by 528elover »

Problem: Your CV Boots have ripped or are torn

Cause: Wear on the rubber boots; road debris, etc.

Fix: See below.

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Tools Required: Jack Stands, 8mm bit, Bit Extension, Ratcheting Socket Wrench, Torque Wrench, Chisels, Dead Blow Hammer, Snap-ring Pliers, Paint (optional)

Supplies Required: New CV Boot Kit (with boot, snap ring, clamps, grease)

Torque Specs: 42-48 lbs. (half-axle bolts to differential and flange)

1. First, get a good replacement CV boot kit. You'll need 2 per half-axle. The kit should come with the following: (1) new boots; (2) new snap ring; (3) pre-measured packet of grease; (4) new clamp ring. My kit had the joint caps already on the boots themselves and permanently secured with a ring.

2. Firmly support the car on jack stands. See separate FAQ.

3. Soak the drive-axle bolts with solvent in advance (i.e., PB blaster). Using an 8mm hex bit with an extension and racket carefully loosen the INNER bolts first. Don't strip the hex bolt heads, or you'll have a helluva-time removing them. Next, loosen the OUTER bolts. [NOTE: If the car is on jack stands, and the rear wheels hanging it is easiest to remove the lower bolts, as the top bolt will be obscured by the boot itself. You can loosen two bolts, then deactivate the parking brake and spin the shaft to get to the other bolts.] After all the bolts are loosened, remove the INNER half-axle from the differential. Next, carefully lift the half-axle toward the cavity to the left or right of the differential and remove the half-axle from the OUTER connection.

4. The next part of the process is as messy as anything you will accomplish, so get lots of shop towels (i.e., cheap blue stuff at Autozone), Odorless Mineral Spirits at Home Depot, and a pair of "snap-ring pliers." You may also need a block of wood and a set of chisels to pound the joints off the axle itself.

5. Review the assembly carefully, before disassembling anything. Taking pictures always help in the reassembly process, in case you've forgotten anything. Remove the snap-ring with a pair of snap-ring pliers. To remove the joint from the axle carefully use a Dead-Blow Hammer (different from a regular hammer) and pound on the joint cap to remove the joint from the axle. [Pound gently and carefully -- this may take a awhile, so be patient].

6. Once the joint is removed from the axle, cut away the old boot, and clean the entire shaft with mineral spirits. Repeat on the other side.

7. You might want to paint your half-axle. I painted my inner section (i.e., the area which is uncovered by any parts) with a CVT High Temp Caliper paint in silver. It looks brand new!

8. Reassembly is the reverse of disassembly. Put on the clamp ring, new CV boot (using some dishwashing detergent is helpful on getting the boot on easily), and then the joint onto the axle. Don't forget to put the snap-ring on with snap-ring pliers. The trickiest part is getting the grease back into the joint. You should get some Permatex Aviation Form-A-Gasket No. 3 Sealant to seal the joint to the cap. Let it sit about 10 minutes after spreading on the sealant before putting the cap on the joint.

9. NOTE: Make sure you line up the bolt holes on the front of the cap with the rear of the cap (i.e., joint section), otherwise you'll have to take it all apart and reassemble. It is helpful to put the bolts through the front cap and through the while you are reassembling to make sure everything is lined up.

10. Once you've completed everything, then clean it up, and put it back into the car. Start with the OUTER section first, then the INNER section. Make sure to torque the bolts to the correct torque. Per Bentley, the correct torque is 42-48 ft-lbs. You should engage the parking brake while you are tightening, or the whole shaft will rotate.

11. Once all the bolts are tightened, check your work, lower the car, and go for a spin.

Hope this helps! Good luck!
528elover
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