Center Bearing Hanger replacement instructions

I finished the replacement Center Bearing Hanger this weekend. I did not replace the bearing, only the rubber hanger.

By the way amx1397 was a big help in describing the process to me. I asked him a lot of questions and want to thank him for the responses.

Comments:

1) I did not find it necessary to remove the exhaust. The exhaust is not in the way of the removal of the loose rear section of the driveshaft. It was very tight fit for the pistol style air wrench to remove the axle flange fasteners. I did try a right-angle air wrench but the one I used was not strong enough to break the fasteners loose. I had to push the still mounted exhaust to the right to squeeze in the air wrench. It was so tight I didn’t realize that I had bumped the direction pin on the air wrench to tighten a couple of times.

2) The Rubber of the center bearing hanger is much tighter on the bearing than I expected. Molded into the rubber that surrounds the bearing is a metal retaining ring. This ring appears to have (3) locations where it is compressed to provide a tight fit to the bearing. This make the rubber both hard to get off the bearing and hard to install a new one. I did not have the right kind of tools in order to either remove or press a new bearing on to the driveshaft. My bearing turned nicely and so I reused it but didn’t have good options to install another one.

3) This would be difficult to do if the car is not on a hoist. I would have been nervous when prying at the axle flange and also needed the room to under the car to move around easily. As it was this job took me 3 ½ hours. I do move a little slower when doing a new task to make sure I doing things properly.

4) I had an abundance of parts when working on it just in case. I had an assembled hanger with a bearing installed. I had a loose hanger without a bearing. I had loose bearings. I had an agreement for a remote shop to press the bearing off and a new one on if I needed that help, but I was hoping to avoid using them. It would have required me leaving the area and coming back. In retrospect, I should have just carried the shaft there as soon as I removed it. Getting the mount off and a new one on was a huge pain.



Tools needed:

· Internal Torx driver: T60 (for the Axle mounted tri-lobed flange bolts)
· Open end wrench: 18 mm. (for the Axle mounted tri-lobed flange nuts)
· Pry bar, or 2 (for the Axle mounted tri-lobed flange)
· External torx driver: E12 (for the center bearing hanger)
· Hex socket: 13 mm (for the cross-tunnel plate.)
· Hex deep socket: 8 mm (for the heat shield)
· Paint marker or similar (to mark the positions of the axle flange and drive shaft halves)
· Torque wrench to torque the axle flange fasteners.


1) Mark all the aligned locations on the axle flange and the separating sections of the driveshaft with the paint marker.
a. I marked each lobe of the axle flange with I, II and III lines. Make sure to mark these extensively because it’s likely you will wipe off the marks if they are in areas that will be handled later.
b. I marked the drive shaft cast-in orientation nubs. There are two on the rear section of the shaft and one on the forward section of the shaft. These are supposed to be aligned when they are assembled in order to maintain balance, but they are quite a distance from each other and not sharply defined. The idea is to align the single mark between the double mark. Because I knew that they would not be easy to align I marked some spline teeth, but these marks did not stay on in my handling of the shaft. I did find marking the cast nubs made them a lot easier to locate later.

2) Remove the (4) rear heat shield fasteners. I was able to slide this forward out of the way enough to access the rear part of the driveshaft. The forward two are shared with a more forward mounted heat shield.

3) Remove the (2) center bearing hanger assembly fasteners. These have a captured flag nut on the inside of a sheet metal box housing. The fasteners have some float within the housing. The holes in the box housing are slotted.

4) Remove the (4) cross-tunnel plate fasteners. These screw into a sheet metal c-section with extrusion formed threads that are part of the c-section.

5) Remove the (3) Axle flange bolts and nuts. Don’t worry the shaft won’t fall at this point even after the fasteners are removed.

6) Pull the forward convoluted shaft seal off the forward portion of the shaft. It is in a groove and will roll rearward. Just working it off with your hand should work without any tools. Using any tools might risk cutting it.

7) Separate the axle drive shaft flange from the flexible driveshaft coupling disc that is still bolted to the axle. This was a struggle for me. I was hesitant to work this too much at first for fear of cutting the rubber coupling disc. This attachment has a slender center bushing to provide a true center and a bushing at each of the bolted locations that fit into the tri lobed flange. They insert about 3/16” into the flange and provided the resistance to separating this assembly. I sprayed them with penetrating oil where I could and just kept working these lobes. I found prying against the remaining disc bolts provided a stop for the pry bar and helped to provide a solid fulcrum. The bushings should stay inside of the flexible disc and the centering bushing should stay attached to the axle.
a. This step was very frustrating and I don’t think I would have been comfortable doing this with the car on jack stands. I was using a hoist and it was difficult there so without the maneuverability it would have been very difficult. I think this step took me about ½ hour to complete.

8) Push the driveshaft forward. It will travel forward in the slip spline enough to clear the longer centering bushing on the axle. Drop it down to clear the axle and then pull it rearward separating the slip spline of the driveshaft. (This is where I tried to mark the individual splines but those marks did not stay in place since the parts were greasy. Maybe it could have worked if I wiped the areas first.)

9) Remove the rear section of the driveshaft.

10) Pry off the remaining rubber hanger from the center bearing. This was much more difficult than I thought it would be, see my comment above. I supported my shaft in a vise without clamping hard, just enough to stabilize it. I then worked the rubber off the bearing using channel lock pliers to pull the rubber at the edge of rubber which slightly overlaps the rear outside diameter of the bearing. It will only come off in one direction, there is a shoulder stop on the forward side of the rubber to allow the bearing a stop position. When it is completely removed, the old hanger which surrounded the bearing, was really distorted. I doubt that the bearing once installed in the mount could be removed without damaging the mount.

11) Install the new rubber hanger. Again this was difficult. I had hoped to use the vise but couldn’t find a way to use this as a press. My method was a wooden block and heavy soft mallet. But that wasn’t doing the job, I couldn’t get it fully installed. I then turned to a heavy mallet on the wood block. I was surprised that was enough of a difference but it did work. After starting this task, I wished I had used an old trick used to install bicycle grips on the handlebar. In that method you take bar soap and wet it smearing the soapy slurry on the rubber areas. For bicycle grips it allows them to slide right on and then when the water evaporates they stay in a fixed location. I don’t know what part of the resistance was friction from the rubber or from the compression of the over-molded steel ring. Eventually I did get it installed. The bearing seemed to move freely so the side loading in the installation didn’t seem to bother it.

12) Reinstall the drive shaft, aligning the marks on the slip spline and the axle flange to maintain the balance.

13) Reinstall all the fasteners. Keep the center bearing hanger square when reinstalling. It has slotted holes so make sure it doesn’t get installed off angle to the drive shaft axis.

14) Make sure the rubber boot over the driveshaft slip joint is reinstalled.

15) Torque the axle flange fasteners to the proper installation torque.