Control arm to control arm dimension
#1
Melting Slicks
Thread Starter
Control arm to control arm dimension
I noticed my upper control arms have a stack of shims on each side, rear end of the crossbar. I know one side has none at the front, the other has one. The car isn't giving me any trouble handling other than maybe being a bit resistant to turning, tracks pretty straight. I'm wondering if the alignment shop set it up with a lot of caster, pulling the upper ball joints back. Could be the springs are sagged, or maybe the crossmember has sagged?
I would like to check the dimension between upper control arm mounting flanges, see if there's any evidence of sagging of the cross member. I find it hard to believe this is a problem but thought I'd check anyway. The Chassis Service manual doesn't provide much detail, this dimension isn't shown. I found a frame dimension drawing on-line for a 79 which had this dimension. Not sure whether it's the same for 70?
Does anybody know what this dimension should be?
I can check the riding height to get an idea of whether the springs are weak.
I would like to check the dimension between upper control arm mounting flanges, see if there's any evidence of sagging of the cross member. I find it hard to believe this is a problem but thought I'd check anyway. The Chassis Service manual doesn't provide much detail, this dimension isn't shown. I found a frame dimension drawing on-line for a 79 which had this dimension. Not sure whether it's the same for 70?
Does anybody know what this dimension should be?
I can check the riding height to get an idea of whether the springs are weak.
Last edited by BBCorv70; 04-25-2012 at 10:30 AM. Reason: Corrected remark about where shims were placed
#4
Melting Slicks
Thread Starter
Here is a diagram for a 79 Corvette, only one I found with the dimension of interest, identified as 'A'. This diagram specs 26 3/8 inches. I fashioned a makeshift plumbob, measured 26 1/4 inches. If this dimension is shared between 70 and 79, seems pretty close. I'd guess the shop may have been maxing out the caster based on the pattern of shims.
#5
Melting Slicks
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You're not doing yourself a favor by having the alignment shop set your car to the bias-ply tire settings of 1970 if you're now running radial tires of possibly a different, meaning wider, size. VB&P and Guildstrand websites give recommendations for 4 wheel alignment based on different driving styles.
My '69 frame drawing does not list that dimension.
My '69 frame drawing does not list that dimension.
#6
Melting Slicks
Thread Starter
I don't know what specs the shop set the alignment to. I had it done a few years ago going through another shop. It seems they were going for a lot of caster, keep the car tracking straight with the trade off of having it more resistant to turning. For now it's more a matter of curiousity than a problem.
Thanks for the tip on the updated alignment specs. I am running much wider tires than the originals, radials as well.
Thanks for the tip on the updated alignment specs. I am running much wider tires than the originals, radials as well.
#7
Melting Slicks
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Here is a diagram for a 79 Corvette, only one I found with the dimension of interest, identified as 'A'. This diagram specs 26 3/8 inches. I fashioned a makeshift plumbob, measured 26 1/4 inches. If this dimension is shared between 70 and 79, seems pretty close. I'd guess the shop may have been maxing out the caster based on the pattern of shims.