 7.Then the center crank slides...  7.Then the center crank slides on, followed by a steel spacer and the second bearing and washer. |  8.Finally, the mount is threaded...  8.Finally, the mount is threaded to the Allen bolt. That large flat surface area is what will need to be welded to the diff cover. |  9.On '63-72 GM trucks, it...  9.On '63-72 GM trucks, it is necessary to remove the crooked crossmember that resides right behind the rear axle. If you're not running a rear-mounted gas tank, the crossmember could simply be relocated rearward a few inches. The same rivets hold the Panhard frame mount, too. So the extra effort was not in vain. |
 10.Now it was time to remove...  10.Now it was time to remove the stock diff cover, which we will be replacing with a new chrome one. We also did some cleanup work on the housing, which included cutting off the stock Panhard mount and grinding the top lip completely smooth. |  11.Chris then cleaned up the...  11.Chris then cleaned up the area where the mounting tabs for the support bracket would be welded. |  12.These tabs were temporarily...  12.These tabs were temporarily mounted to the support bracket until they were tacked to the axlehousing. |
 13.The goal is not only to...  13.The goal is not only to center the support around the housing, but also to center the tabs exactly between the framerails - all while being level from side to side and with the ground. Once it was, the center mount and the support tabs were tacked into the place, and then the Watt's assembly was removed for the final welding. |  14.Axle tubes will warp fairly...  14.Axle tubes will warp fairly easily, so extra precaution must be taken when welding on them. Extra care included a wet towel, compressed air, and welding one bead per side at a time. At this time we covered the other areas and painted the housing gloss black. |  15.Since the mounting area...  15.Since the mounting area on the diff cover is not perfectly flat, Chris cut a notch out of a piece of tubing, welded it in as a filler piece, and ground the area smooth. |
 16.Now the new diff cover...  16.Now the new diff cover for our 12-bolt could be installed permanently. We used silver RTV sealer. |  17.We even used new stainless...  17.We even used new stainless button head bolts with our new cover. We hit the welded area with some silver paint. If you have more time, you could have the diff cover rechromed. |  18.These bearings will never...  18.These bearings will never see the abuse that they would on the front of a truck, but it's still important to grease them before assembly. |