Packing Rear Wheel Bearings

[toobroketoretire]

Our C3's came from the factory with the very stiff "string style" grease that had to be replaced about every 50,000 miles because the oil in that grease eventually migrated out past the inner seals; leaving only the hard lithium soap carrier behind. Now days it's best to use any #2 grease and fill the hubs about 90% full and that will last the entire 250,000 mile service life of the new bearings. When I install new bearings I use a 6" long 1/8" pipe extension on my grease gun hose and just before installing the inside cone I pump as much grease as I can into the hub then mush the inside bearing into place.

The nice thing about the lighter #2 grease is it gets "sloppy" when it warms and it's that sloppy texture that always ensures the bearings stay lubricated.............much like the oil bearings used in trucks and heavy equipment. When you drive alongside any modern truck trailer you can see the aluminum hubs with their clear windows in the center of the wheel with a red rubber plug in the middle. Just ordinary 50 weight motor oil is used in those bearings which sure beats hand-packing them like was done in the old days.

 

[GTR1999]

The newer greases are better but you must leave some room for expansion. Many have tried the bearing packing tool and they do not work. Also bearing setup is critical, while the bearings are not high precision machine- tool bearings they should be setup with minimal endplay. The spec is 001-008" but it seems everyone quotes 002" as the magic number when in fact it isn't. I set them up for -0- lateral play and that comes out close to 002 many times but not always. This can only be achieved by surface grinding the parts first parallel and then to size.

Many places do rear bearings but they are all over the place. Some have and still sell bearing supports with zerk fitting for future lubrication but they don't work either as you never know the amount they need. I plug all the supports that I work on when rebuilding arms.

You can't work on the grease without correctly setting up the bearings, at least if you want a good job. Also never attempt to reuse old bearings. They are pressed on the spindle and should be replaced with new, USA Timkens are best, bearings.

 

[Vettehead Mikey]

Listen to Gary. He is universally recognized as the BEST in the business.

 

[SVO]

Never seen Gary's position on this, but my position is to never polish a stub axle to achieve a slip fit with the axle bearings. The axle bearings need to be a press fit.

 

[GTR1999]

Never seen Gary's position on this, but my position is to never polish a stub axle to achieve a slip fit with the axle bearings. The axle bearings need to be a press fit.

There are many who run slip fit bearings and typically are the guys who will break them down yearly and regrease them, check them, etc. In that situation you can regrease the bearings. However I do not advise slip fitting the rear axles to bearings, either inner or outer. These are the drive axles with a lot more load on them. The early 63's were slip fit and also had axles shear, wheels come off in use. GM revised the design to press fit by mid '63 and kept the design until the end of the run in '82. I turn down any request for slip fitting axles and bearings.

Since we are speaking of axles and setup. Many know the stock axles came apart under higher HP abusive loads. They broke many times at the junction of the threaded end and splines. The mid 70's QC was bad on a lot of the GM cars including the corvette. I have seen plenty of twisted axle splines in 75-82 axles. The diff axles were also soft and caused differential issues. The current offerings in new format are imported, sold on e**y and by many vendors, USA made by Spencer Forge - what I use for stock axles, and Tom's 31 spline- what I use for HP builds. Tom's are the best and in addition to the 31 spline vs the stock 17, have a solid shaft using the larger bearings inner/outer. Stock axles step down to a smaller inner bearing. For setting up these I do not attempt to go by the 002 endplay nonsense flooding the internet these days. The bearings are set up for a preload. So far I haven't seen any come back and we haven't broken any on our track car. Now solid spicers are another story!

 

[Vettehead Mikey]

Never seen Gary's position on this, but my position is to never polish a stub axle to achieve a slip fit with the axle bearings. The axle bearings need to be a press fit.

Agreed on that! I don't think anyone who truly understands the dynamic of the rear axles would do that. GM made quite a blunder with the early C2s with a slip fit bearing.