68 rear spindle without rivet holes?

[Robert Holmes]

I have a 68 which I've had since 74. I discovered this years ago, but figured it was just a factory mistake. The rear brake disk on the drivers side has no rivets, in fact, the spindle has no holes except for the studs! It couldn't be riveted, and worse, it's impossible to adjust the parking brake shoes! The spindle looks stock, with the same cast in part number as the pass. side.

Is this a replacement, or could it be from an earlier drum brake car?
Thanks,
Robert Holmes

[Joe L.]

Re: 68 rear spindle without rivet holes?

Robert------

I did not even think that a 63-64 spindle for use with drum brakes would even work on a disc brake 65+. However, apparently they will because I expect that's what you've got. I really don't think that this is a "factory" mistake, though. I just don't see how such an assembly would have made it through the inspection process at the sub-assembly plant where these trailing arms were built up. In fact, I don't see how they would even have had the drum brake spindles in the plant by the time that trailing arms for your car were assembled. Complete trailing arm assemblies were never available in SERVICE, so the plant would have ceased to produce them after the 1964 model year (even though a few left-over assemblies were used during the 1965 model year).

Here's something to check: look at the casting dates on the spindle supports. It's possible that some owner prior to you destroyed an entire trailing arm assembly some how or another and a complete replacement (from a 63-64) was obtained from a Corvette salvage yard and installed on the car. If the casting dates on that side are 62, 63, or 64, this is likely what happened. Otherwise, if the casting dates are correct, then apparently someone just replaced a spindle on your car with an incorrect 63-64 spindle.

[Joe L.]

Re: 68 rear spindle without rivet holes?

Robert------

I did not even think that a 63-64 spindle for use with drum brakes would even work on a disc brake 65+. However, apparently they will because I expect that's what you've got. I really don't think that this is a "factory" mistake, though. I just don't see how such an assembly would have made it through the inspection process at the sub-assembly plant where these trailing arms were built up. In fact, I don't see how they would even have had the drum brake spindles in the plant by the time that trailing arms for your car were assembled. Complete trailing arm assemblies were never available in SERVICE, so the plant would have ceased to produce them after the 1964 model year (even though a few left-over assemblies were used during the 1965 model year).

Here's something to check: look at the casting dates on the spindle supports. It's possible that some owner prior to you destroyed an entire trailing arm assembly some how or another and a complete replacement (from a 63-64) was obtained from a Corvette salvage yard and installed on the car. If the casting dates on that side are 62, 63, or 64, this is likely what happened. Otherwise, if the casting dates are correct, then apparently someone just replaced a spindle on your car with an incorrect 63-64 spindle.

[Robert Holmes]

Re: 68 rear spindle without rivet holes?

Thanks Joe,
I'll check dates, but I'm guessing a previous owner had bearing problems and replaced the spindle with one from a junkyard. I had both bearings apart about '78 to check condition and set clearance, and all seemed in good shape except for the odd spindle.

I'm getting the car put back to original so I guess I should start looking for a correct spindle, or would it be possible to drill the holes?

Thanks again,
Robert Holmes

[Robert Holmes]

Re: 68 rear spindle without rivet holes?

Thanks Joe,
I'll check dates, but I'm guessing a previous owner had bearing problems and replaced the spindle with one from a junkyard. I had both bearings apart about '78 to check condition and set clearance, and all seemed in good shape except for the odd spindle.

I'm getting the car put back to original so I guess I should start looking for a correct spindle, or would it be possible to drill the holes?

Thanks again,
Robert Holmes

[Joe L.]

Re: 68 rear spindle without rivet holes?

Robert-----

I really think that I'd purchase a correct spindle for the car. Actually, the rivet holes are rather a minor feature since most folks never rivet replacement rotors to the spindles, anyway. In fact, many replacement rotors nowadays don't even have the rivet holes anymore. You could easily drill the parking brake adjustment hole. However, notwithstanding the fact that your car has been equipped with one of these spindles for a long time, I really think that there are other differences in the 63-64 and 65-82 spindles. I would recommend using a known-correct part. Brand new aftermarket replacement spindles with the rotor mounting surface guaranteed to be true to .0005" (yes, that's .0005") TIR are available for about $140.

[Joe L.]

Re: 68 rear spindle without rivet holes?

Robert-----

I really think that I'd purchase a correct spindle for the car. Actually, the rivet holes are rather a minor feature since most folks never rivet replacement rotors to the spindles, anyway. In fact, many replacement rotors nowadays don't even have the rivet holes anymore. You could easily drill the parking brake adjustment hole. However, notwithstanding the fact that your car has been equipped with one of these spindles for a long time, I really think that there are other differences in the 63-64 and 65-82 spindles. I would recommend using a known-correct part. Brand new aftermarket replacement spindles with the rotor mounting surface guaranteed to be true to .0005" (yes, that's .0005") TIR are available for about $140.

[Wayne M.]

Re: 68 rear spindle without rivet holes?

Joe, Robert --- Had the same set-up when I bought a '65; didn't learn 'til later that I had a '63/64 type spindle. The only clue that something was amiss were the washers that had to be slipped over the wheel studs on the spindle before installing the disc; otherwise the rotor would not center in the caliper opening (disc too far inward). Be interesting to know whether that's Robert's situation as well.

[Wayne M.]

Re: 68 rear spindle without rivet holes?

Joe, Robert --- Had the same set-up when I bought a '65; didn't learn 'til later that I had a '63/64 type spindle. The only clue that something was amiss were the washers that had to be slipped over the wheel studs on the spindle before installing the disc; otherwise the rotor would not center in the caliper opening (disc too far inward). Be interesting to know whether that's Robert's situation as well.

[Joe L.]

Re: 68 rear spindle without rivet holes?

Wayne-----

I figured that there was likely an off-set difference on these spindles, but I was not at all sure until you confirmed it. I definitely would NOT RECOMMEND the use of washers to compensate for this difference and make the 63-64 spindles usable in disc brake applications.

[Joe L.]

Re: 68 rear spindle without rivet holes?

Wayne-----

I figured that there was likely an off-set difference on these spindles, but I was not at all sure until you confirmed it. I definitely would NOT RECOMMEND the use of washers to compensate for this difference and make the 63-64 spindles usable in disc brake applications.

[Robert Holmes]

Re: 68 rear spindle without rivet holes?

Wayne, Joe,
This continues to puzzle me! There are no spacers anywhere, and the disk appears to be well centered in the caliper, checked with nuts holding the disk firm against the spindle. A quick check showed it within .03 of center in the caliper. Everything seems to match the opposite side, which has the correct spindle with all rivet and brake adjust holes. (Rivets are missing)

I plan to rebuild the rear swing arms next winter since it's been about 20 years since I touched the bearings etc., and the consequence of failure is expensive! Maybe then I can get to the bottom of this.

I've driven the car like this since '74 with no ill effects, so whatever I've got seems to at least be reliable!

Thanks for the input.
Robert Holmes

[Robert Holmes]

Re: 68 rear spindle without rivet holes?

Wayne, Joe,
This continues to puzzle me! There are no spacers anywhere, and the disk appears to be well centered in the caliper, checked with nuts holding the disk firm against the spindle. A quick check showed it within .03 of center in the caliper. Everything seems to match the opposite side, which has the correct spindle with all rivet and brake adjust holes. (Rivets are missing)

I plan to rebuild the rear swing arms next winter since it's been about 20 years since I touched the bearings etc., and the consequence of failure is expensive! Maybe then I can get to the bottom of this.

I've driven the car like this since '74 with no ill effects, so whatever I've got seems to at least be reliable!

Thanks for the input.
Robert Holmes

[Wayne W.]

Re: 68 rear spindle without rivet holes?

There is so much variance in the cuts on some of the spindles and rotors that it is not unlikely that you could match or machine one that wouldn`t require shiming. The only other thing that would be a problem is the adjustment hole and the short studs, which are easy to replace.

[Wayne W.]

Re: 68 rear spindle without rivet holes?

There is so much variance in the cuts on some of the spindles and rotors that it is not unlikely that you could match or machine one that wouldn`t require shiming. The only other thing that would be a problem is the adjustment hole and the short studs, which are easy to replace.