blu73

A bit of a back story first. As we all should know, in '63 the Corvette came with the new independent rear suspension. The service manual for that model year directed the mechanic on how to check the amount of end play in the rear spindle bearings. If out of spec, repairs were to be made as needed. When the spindle was removed and reinstalled, there were a few special tools used, but not a hydraulic press and other heavy duty tools to remove and reinstall the bearings. They were a slip fit and the spindle nut was torqued to 50 foot pounds and the job was done. That info is right out of a '63 service manual.

As urban legend has it, some dealer mechanics didn't do as the service manual directed and Chevrolet soon found themselves replacing parts under warranty. At least that's one version of why the bearings then became a press fit.

Another reason would be that the design and maintenance instructions really were deficient.

So, now to my question. Are there any owners of '63 'vettes still going by the original service manual and using original rear spindle assemblies? Are your spindles still made to '63 specs or have you had to deal with the way spindle assemblies were "upgraded" to be a press fit?

When I look at how the whole assembly is stacked up within the bearing housing, it appears pretty solid. Going from the outside and working inward, the inner race of the outer bearing is held against a shoulder machined on the spindle. Next, the spacer and shims are held against the inner races of both the outer and inner bearings. Finally, the flange is held against the inner race of the inner bearing by the flange nut that is torqued down. In my opinion, that's a solid stack of parts held in place pretty securely. So, how does a spindle get damaged by a bearing failing in some way? Lack of lubrication? Poor maintenance? Bad end play adjustments? What gives?

I'm asking these questions because I am thinking of altering my spindles to be a slip fit for the bearings. I would be more likely to do better service on the rear spindle pieces. If it worked well in '63 with properly maintained and set up spindle bearings, why not now.

Let's face it, not many of us have the equipment to maintain these rear spindles the way the service manual explains, and good mechanics who understand these systems are getting harder to find.

Okay then. If you're still enjoying the original pieces in your '63, let me know how it's going. Also, if you are someone who has changed your later spindles to a slip fit for the bearings, I'd like to hear of your experiences also.

Pro or con. Let's hear about it.

TCracingCA

You can slip fit them! I would torque that nut more thou!

The primary reason for the Press fit, was so the spindle didn’t try to leave the hub as fast, if the inside end somewhere failed drum brakes!

Plenty of threads on the pros and cons!

GTR1999

GM didn't get very far into 63 production before the rear wheel bearings were slipping on the axles, heating up and shearing the axle. With drum brakes there is nothing at that point to even attempt to hold the wheel on and wheels were passing by the drivers! GM went to slip fit for a good reason, like keeping their customers alive.

Unlike the front axles the rear are obviously drive axles under load. I have read, heard, and talked to plenty who slip fit rear axles and think it's great. Some are road racers that break down the bearings very often. Personally I pass on any request to slip fit rear bearings. If they are properly setup to start and pressed on you are good for a long time. There is no good reason to attempt to slip rear bearings, other then inexperience which could prove very costly if you have an axle issue.

Factoid

Actually, it didn’t work well which is why they are all press fit, including serviced ‘63 spindles.

SWCDuke

The early slip fit design had a high failure rate. There was an "interim" solution that went into production around November, and the final press fit design went into production in early December.

This is all described in an detailed TSB that I'm sure is somewhere in the archives.

Along with the new press fit design, GM eliminated the 30K mile repack recommendation.

In the event of failure, or as a general precautionary rebuild, I recommend retaining the press fit design, use name brand bearings and a high quality full synthetic grease like Mobil 1, set end play near the low end of the allowable range, and they should outlive all of us.

The 1963 Corvette Shop Manual was published about the time the car went into production and was never updated even though many changes occurred over the course of the model year and later years that are retroactive to '63 models. In addition to the rear wheel bearing setup there were significant changes to the Positraction an KO wheel designs.

Duke

Dan64

I think this thread may help answer my question. I have a 64, has been sitting for 40 years, in restoration process. Went to remove rear axle shafts to inspect bearings, seals etc. 63 service manual made it look pretty straight forward, and assembly views did also. Remove spindle nut, companion flange, and remove brake drum, remove spindle. Followed procedure but they will not come out. Tried dead blow hammer, etc. no luck. Now I see this post as I was searching for info. Do the axle shafts have to be pressed out? Not sure if I am understanding slip fit and press fit discussion. Appreciate any help.

GTR1999

Mid 63-82 have an interference fit between the Axle OD and the Bearing ID. The inner bearing press fit is holding the axle in place. You won't be able to drive them out with a mallet. You need to buy the steel tool made for this and use a 4 or 5 lb mini sledge to drive them out. I never use a press anymore, which is more likely to break or bend a part.

craig1952

If perfectly round a slip fit might part would be .001-.002 smaller than what it’s going in to. A press fit would be a few thousandths larger. It doesn’t take much difference to be a slip or press fit.

tbarb

Gary,

When you drive them out do you rig up something to hold the trailing arm or just sit it on the bench and hit away. In your opinion how much larger is the spindle area where the bearing slips over for interference fit.

The reason I ask is because my 67 car has only a few thousand miles since the bearings were replaced but that was twenty five years ago. No issues but I wonder if the grease has separated.

Dan64

Thanks GTR for the help.

GTR1999

Tim
I first see how well the tool threads on to the axle. It should screw on without issue. If not the threads may be rolled. Once the tool is on the axle I hold the arm at about a 45* angle with my left hand and drive out the axle with the right. Hard to tell if the grease has separated out, depends on what type was used.25 years ago I would have used Mobil one