I got my new lower shock mounts installed and the left one looks wrong to me. The right and left mounts are at very different angles compared to the bearing support.

There is no way to install them wrong. Is something machined wrong?
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This is not looking correct. The spindle support has a D made in to the side the nut is on, it is possible the D is worn due to a bad old support. We just repaired one in our shop around January on the 63 chassis we restored.

If the D is rounded in the support, the shock bolt can move to the wrong position. I'll see if I have a picture.

Willcox

 

I just got back in from the garage. I knocked the left mount back out. There is enough slop in the support that I have about 15 deg of play. I installed the right side 1st and there was no play so I didn't pay that much attention to the orientation. I can orient it so it is correct (or at least matching the other side). If I reinstall it in the correct orientation it should stay, right, or is the support bad?

 

The shock should maintain the proper orientation. Seems like the shock would have to bend in order for that to change once everything is bolted together.

 

the shock will try to rotate the shock support, that is why the "D" is in the spindle support-to stop the rotation. however, i'd bet that it would work for a while. the shock may have a shorter life. what's the worst that could happen? the shock break off at the lower support when you hit that bump in the curve going 70, 80+ mph?
i would be interested in the willcox fix . . . my 2 cents

 

I have reinstalled it and torqued it to 80 ft lbs. It gave no indication that it wanted to rotate while I was tightening the nut.

It is a rebuilt unit, not me cleaning up and reusing the old one. I will call the rebuilder Monday morning and talk to them about it. If they are agreeable I'm leaning towards taking some acurate measurements and keeping an eye on it be sure it isn't moving. If it does move I should be able to remove just the bearing assembly and swap it out.

 

It will not work if the D is gone. With the 15 deg. movement you have with your new bolt, the old one must have really been moving around. The problem is that the shock will exert more than enough force to move the shock bolt without the D in place. The D is not the only thing that keeps the bolt from moving either. On the opposite side on the shock bolt there are teeth that bite in to the rear support and combined with the D they hold the support at the correct position.

To answer your question, yes. If you can move the shock bolt in the support you need to either have it repaired or replace it. The shock will force movement in the bolt which will in turn eat up the new bolt as well as further deteriorate the old support.

Willcox

 

Hi S489 and Wilcox,
Nice thoughtful explaination of this situation!!!!
Regards,
Alan

 

Dang, that means at least another week to get the car back drivable.

I was hoping the D was more for alignment than to stop twisting. The teeth on the other end seem to grab real well. At first thought I wouldn't think the shock would put that much force on the mount, but it is essentially mounted to a lever which will amplify the force and make the mount want to twist. The more I think about it the more I think I agree with you. Better to fix it now than take it all apart again.

Thanks for the advice.

 

The rear suspension is supposed to be raised to "D" height specified in the AIM before tightening the shock mount bolt. Basically that means raising the trailing arm to ride height before torquing the shock mount bolts. If you do that I think you will find that things align just fine.



Rick B.

 

An extremely gifted welder and a milling machine guided by yours truly!
Two things not usually found cheap! Total cost will exceed the cost of a new or used c3 support!

The one and only reason we spent the time fixing the one on the 63 was that we are shooting for NCRS top flight. It was the original open (No web) style support and is not found easily. In this case it probably was cheaper to repair than to purchase a new one. On a C3 the supports are easy to find used, and available new as well.

The one repaired is the one on the left. I have a pic somewhere of the before and after. But if you notice this car was a very early 63 and the support is without a casting date. I have never seen a support with no casting date but this car is a very early 63 and came with the early suspension parts (rare). I can only assume it was so early GM was still working on the parts. December 3rd, 1963 they issued a tsb in which they changed the design of the rear suspention parts. http://willcoxcorvette.com/repairand...lp.php?hID=220



Willcox -

 

I just installed my two new shock mounts yesterday and they are tight due to the d shape in the spindle support fork and the shock mount itself. Its solid and does not move.

 

That was interesting! And in that case there was no easy fix, unfortunately!

 

To my knowlege there is not a fix for this part "on the car". Off the car is a real pain!

Willcox

 

Fortunatly off the car isn't that big a deal. I just put the TA in so everything is new and it should come out pretty easily, it's just the wrench time, no cutting this time, thank goodness. The pain is if I have to ship the unit back across the country and wait for it to be repaired and shipped back.

FYI, I just took a close up picture of the D hole. If I hadn't just payed for a rebuilt assembly I would be tempted to have the shock mount modified to fit the hole.

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Hi, did you get your T/A rebuilt buy one of the many supporting vendors or is this a private mechanic you deal with? Just curious, how difficult was it getting them removed? Did ya have to cut them out like I hear about all the time? What all was involved in your rebuild? New parts, etc. Did you get a fair price.
Thx,
R

 

Someone rebuilt this and sent it back to you this way? Probably an honest oversight!

Willcox

 

It was from a supporting vendor. I don't want to say who it was until after I talk to them Monday morning and see how they propose to make it right.

It is a rebuilt unit, $375 + a $300 core charge. It included new bearings, seals, parking brake shoes & hardware and a new rotor. I thought it was a good deal since I didn't have to buy the bearing set up tools and an Arbor press. It was mostly a matter of saving time and I figured some one who does this all the time would be better suited than I to judge the condition of the old parts, kind of ironic.

Getting the TAs out was a chore. All of the bolts that went thru bushings were rust welded. The shock mounts were the hardest to get out. I used a combination of sawzall, grinder and cutting torch. I had to drill both the camber adjusting bolts out. The TA pivot bolts cut fairly easy, a couple hours each arm. I used Lenox coated blades and cutting oil. If I hadn't struggled so much with all the other bolts I would have said the pivot bolts were hard but I refined my technique by the time I got to them.

Three years ago, I replaced the leaf spring, differential cover and exhaust. While I had the whole car up on stands I degreased, wire brushed and painted as much of the frame as could with Por-15. This project I did both trailing arms, the rear shocks and all the remaining bushings. This was brought on by a $40 spindle bearing failing.

Hopefully this will be it for a couple years. I probably should have done the u-joints but I didn't.

 

I hear ya on the grinding and cutting. I grinded my shock mounts off last weekend. Had a 3 page thread on the incident. Got lots of help and many tips/tricks from many. Sawzall, was not working so I had to grind/cut them off. What a mess. I will probably attempt new or rebuilt T/A's in the future. Not sure what warrants a T/A rebuild. I had my rotors and all end play, beargings check out from a mechanic and it was all within spec. But based on my shock mount fiasco, Im sure my T/A bolt/bushings will be the same P.I.A....

 

I had to replace my bearing and things started to snowball. Once you replace one thing you need to do an alignment so I figured I might as well do it all.