Trailing Arm Question - Part #2

[Joel T.]

Guys;

I just pulled the right rear wheel and drum on my 1963... I removed 3 of the 4 nuts holding the backing plate in place.... All of the backing plate holes are elongated to some extent... I can get almost 1/2" of rotational movement (along the circumference) with the nuts removed/loosened. I got to believe that this is the thumping I have been hearing and probably the reason the car pulls to the right on hard braking and that right read drum is hotter than the other three. If the holes are elongated is it reasonable to believe that the whole brake assembly could not be centered properly versus the drum??

Thoughts, does this make sense?

Where does one find a 1963 right rear backing plate these days?

Joel

[Gary R.]

Re: Trailing Arm Question - Part #2

Joel,
Here is a LH plate from a 63 Fuelie I did the bearings/arms on. The holes were fine no issues, maybe you can compare it to yours.

[Joel T.]

Re: Trailing Arm Question - Part #2

Gary;

I did not take pictures but did remove the nuts and split washers. Bottom line, the holes were somewhat oval in shape, bigger than what you are showing here, and had scrape marks under the split washers which indicates to me that rotation was probably taking place.

Thanks for posting!

Joel

[Stuart F.]

Re: Trailing Arm Question - Part #2

Joel;

Were you using original drums or, perhaps, replacements? Reason I ask is that I redid my brakes this last summer and bought replacement (Generic) drums as I had been told that 40k miles would find my originals junk due to the metallic linings. Well, the replacements just would not adjust right and I had to recut my old ones instead. There was a dimensional difference/relationship between where the lining surface was in the drum to the hub mounting surface. The drums did not fit up snug to the backing plates, rather the was a gap there. The replacements did not have anti-chatter spring grooves or adjustment knockouts either.

Stu Fox

[Joel T.]

Re: Trailing Arm Question - Part #2

Hi Stu;

These are reproduction drums (all around). They do not have the groove for the spring but the do have the knock out for the adjuster... The drums which came with the car were too far gone to cut again so they wound up in the dumpster... I do not think that the drum is the issue... the other three wheels work fine and based upon what I can see on the drum surface, it appears that the shoes line up properly....

How's the weather in Florida?

Joel

[Stuart F.]

Re: Trailing Arm Question - Part #2

Joel;

I was looking for something other than loose bolts as I am sure you were on top of that. As for the backing plate, I seem to recall some discussion on previous threads that some of the major brake parts were interchangeable with some passenger car components. Is that a possibility to locate a replacement? The spindle/hub mounting pattern looks much the same as that on axle housings.

Weather here today is gorgeous - mid 70's and sunny. Our nights still dip down into the mid 40's, so when you go out cruising and come home after dark, it's a bit chilly - specially with the top down. When you're sitting still, there's that darn condensation to contend with. Listen to me complain, Ha! Actually, I like the opportunity to wear my 50th anniversary leather Corvette jacket.

Stu Fox

[Joe L.]

Re: Trailing Arm Question - Part #2

Joel;

I was looking for something other than loose bolts as I am sure you were on top of that. As for the backing plate, I seem to recall some discussion on previous threads that some of the major brake parts were interchangeable with some passenger car components. Is that a possibility to locate a replacement? The spindle/hub mounting pattern looks much the same as that on axle housings.

Weather here today is gorgeous - mid 70's and sunny. Our nights still dip down into the mid 40's, so when you go out cruising and come home after dark, it's a bit chilly - specially with the top down. When you're sitting still, there's that darn condensation to contend with. Listen to me complain, Ha! Actually, I like the opportunity to wear my 50th anniversary leather Corvette jacket.

Stu Fox

Stu and Joel-----


Unfortunately, the 1963-64 Corvette REAR drum brake backing plates were unique to Corvettes. So, they cannot be obtained from another Chevrolet model. The FRONTS are the same as some passenger cars, but not the rears.

I THINK that someone is reproducing these backing plates now, though. It might be America's Finest Corvettes in Ramona, CA.

[Rob M.]

Re: Trailing Arm Question - Part #2

I don't know if it would be secure enough but did you consider to fill the holes by welding them up and redrill the holes?

regards,
Rob.

[Joel T.]

Re: Trailing Arm Question - Part #2

Guys;

Thanks for all the comments. Joe, I will check out America's Finest Corvettes to see what they have.. I've thought about removing the plate and welding thick washers over the existing holes.

Regards to all,

Joel

[Joe L.]

Re: Trailing Arm Question - Part #2

Guys;

Thanks for all the comments. Joe, I will check out America's Finest Corvettes to see what they have.. I've thought about removing the plate and welding thick washers over the existing holes.

Regards to all,

Joel

Joel-----


As long as you get the washers centered on the original hole centerline, that should work. However, it might not be so easy to accomplish the aforementioned. In any event, if you do this, make sure you use HARDENED washers. The original plates were not hardened but if you're going to go to this effort, you might as well have all the wear resistance possible.

[Gary R.]

Re: Trailing Arm Question - Part #2

I think if I was going to do this repair I'd machine up bushings, harden them,and then weld and grind flush. Probably last forever. Check with Brian Bair maybe he has a plate to sell you.

[Joel T.]

Re: Trailing Arm Question - Part #2

Joe/Gary;

Thanks for the input. I think that I will be OK with the washer idea so long as I get all four aligned with the trailing arm bolts... The center of the plate sits snug on the hub so I think I only have a rotational issue as opposed to a centering issue....

I managed to find a guy on CF who just put disks in his 1963 SWC (beautiful car) so I am picking up his two old rear assemblies; bearing housing, spindles, backing plates, brake parts and drums... all which have been recently rebuilt... I suspect that I will just replace my assemblies... but I will keep the old backing plates for restoration as you guys suggest.

Joe, you are absolutely correct (as usual) that those backing plates are not hardened... the lock washers there today have basically helped to chew the holes up fairly well.

Regards,

Joel

[Gary R.]

Re: Trailing Arm Question - Part #2

Let me know how you make out, sounds like a plan. I did a 64 for DB last year as well. I could contact the fellow if you need me too but I think you're good.