Interesting find on "67 rear wheel bearing overhaul

[Joseph E.]

I'm on the last side of a rear wheel bearing service/overhaul on my 1967 L79 roadster and have found something I haven't come across before. The car is a 50K mile original and has had little if anything done to the rear suspension since being built. The exception to this is that the rear spring was replaced at some point by a reproduction which has fatigued. It was obvious during the disassembly process that this car hadn't had its rear bearings serviced before. This assessment was made based upon the uniformity in appearance of components and their rust/dirt/grease buildup. Additionally, the bolts holding things together don't appear to ever have been taken out. The bearing housings were a bear to get out of the trailing arm but the application of a bit of heat and the use of a sledgehammer and spindle knocker persuaded them to relinquish their positions.

The interesting thing I found is that the spindle nut was not torqued to 100 foot-pounds as the manual indicates it should be. Instead, the nut was found the be so loose that it could be removed by hand once the cotter pin was taken out. The only reason I could think that this could be set up this way was to "fudge" the bearing clearances. I cleaned both rear wheel bearings and races on each side to remove as much of the remaining grease as I could get off. Once the parts were "clean", I reassembled the bearings and spindle and torqued the spindle nut to the recommended value. I found that there was no play in the bearings but noticed that there was a slight preload that could be felt when the spindle was rotated in the bearing housing. The bearings are original Hyatt with the GM inner and outer seals still in place. I initially thought that Bubba
had been into each housing but it seems unlikely as the components involved don't seem to have ever been disassembled. Has any other member come across what appears to be a factory done assembly that has had such defficiencies? Thanks.

Joe #45420

[Joe L.]

Re: Interesting find on "67 rear wheel bearing overhaul

I'm on the last side of a rear wheel bearing service/overhaul on my 1967 L79 roadster and have found something I haven't come across before. The car is a 50K mile original and has had little if anything done to the rear suspension since being built. The exception to this is that the rear spring was replaced at some point by a reproduction which has fatigued. It was obvious during the disassembly process that this car hadn't had its rear bearings serviced before. This assessment was made based upon the uniformity in appearance of components and their rust/dirt/grease buildup. Additionally, the bolts holding things together don't appear to ever have been taken out. The bearing housings were a bear to get out of the trailing arm but the application of a bit of heat and the use of a sledgehammer and spindle knocker persuaded them to relinquish their positions.

The interesting thing I found is that the spindle nut was not torqued to 100 foot-pounds as the manual indicates it should be. Instead, the nut was found the be so loose that it could be removed by hand once the cotter pin was taken out. The only reason I could think that this could be set up this way was to "fudge" the bearing clearances. I cleaned both rear wheel bearings and races on each side to remove as much of the remaining grease as I could get off. Once the parts were "clean", I reassembled the bearings and spindle and torqued the spindle nut to the recommended value. I found that there was no play in the bearings but noticed that there was a slight preload that could be felt when the spindle was rotated in the bearing housing. The bearings are original Hyatt with the GM inner and outer seals still in place. I initially thought that Bubba
had been into each housing but it seems unlikely as the components involved don't seem to have ever been disassembled. Has any other member come across what appears to be a factory done assembly that has had such defficiencies? Thanks.

Joe #45420

Joe-----


Did you look for any wear on the ends of the bearing spacer or shim?

[Joseph E.]

Re: Interesting find on "67 rear wheel bearing overhaul

Joe,

I don't see any indications of wear on either end of the bearing spacer or the shim used to adjust clerance. The bearings were in place very tightly as evidenced by the amount of force from my 20 ton press that was needed to "pop" the inner bearing from the spindle. I found the same tight fit when I removed the outer bearing with the assistance of a bearing puller or splitter as it is sometimes called. I'm going to mic up the ID of the bearings and the OD of the spindle where they rest when pressed into position to compare. I believe there should be an interference fit of a few thousandths, .001-.002. Thanks.

Joe #45420

[Gary R.]

Re: Interesting find on "67 rear wheel bearing overhaul

Joe
I have worked on a lot of arms, some never touched others totally wrecked by previous mechanics. I have seen some that were similar to yours but the history of them varied between dealerships and garages working on them.
You're correct to replace them and be sure to torque them to 100 ft/lbs. If you look at the faces of the spacer and shims you'll probably see they are worn, I grind these flat and recommend you do the same. I have found some out as much as 005". Same for new shims, they are not out as much but I always grind them parallel. It saves a lot of grief when you go to put them together.
If you need any help check my link on this job or let me know, hope it helps. Good luck.

http://www.digitalcorvettes.com/forums/showthread.php?t=77000

[Joseph E.]

Re: Interesting find on "67 rear wheel bearing overhaul

Gary,

When I service rear bearing and set the clerances, I always check both the spacer and the shim in at least four places (12,3,6 and 9) to be sure that the spacer or shim is flat. I too grind them flat so that there is no problem with them in the future. The spacer and bearing removed show no wear but I also plan to check each of them in at least four places to see if the pieces are flat. I'll do this just to satisfy my own curiosity but I will be installing new bearings and setting them up properly. Thank you for the reply and offer of assistance if needed.

Joe #45420