Upper control arm shafts
Thread Starter
Instructor
Joined: Jun 2010
Posts: 165
Likes: 0
From: concord ohio
Upper control arm shafts
I'm in the process of rebuilding the front steering of my '78. My question is, the passenger side upper control arm shaft has 7/16" of shims and the drivers side has one very thin shim. Do I need offset shafts to eliminate some shin on the passenger side and invert the shaft to add some to the drivers side? The car had an alignment last summer, so it should be close. Thanks for the help.
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
I'm in the process of rebuilding the front steering of my '78. My question is, the passenger side upper control arm shaft has 7/16" of shims and the drivers side has one very thin shim. Do I need offset shafts to eliminate some shin on the passenger side and invert the shaft to add some to the drivers side? The car had an alignment last summer, so it should be close. Thanks for the help.
out of balance.
if the car handles right and no obvious low side, I would keep an eye on it for future work.
Thread Starter
Instructor
Joined: Jun 2010
Posts: 165
Likes: 0
From: concord ohio
The car handles and drive very well. The height is 29 inches on both sides exactly from the groin to the top of the wheel opening. I have had the car since new, and I can't remember what the shim configuration used to look like. What could be sagging?
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
the A arms can be tweeked, crossmember sags.
don't worry until it can't be aligned or drives bad.
I understand your concern. sorry to worry you.
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,753
From: Charlotte NC
The "odds" that both sides of your upper control arm shim points are very unlikely. It does not matter...becsue then the alignment head are attached and measuered...the technician will be told what to do to make sure that your alignment is correct.
The "problem" that is inherent with the 63-82 Corvettes are that the engine cradle collapses over time. So the distance between your upper control arms begin to come closer to each other...due to bumps in the road, etc. In order to get the control arm to go back out as required....shims are removed to achieve this. When you have NO SHIMS in the upper attachment points. This is when either you have the cradle stretched back to its dimension (or at least to where you can install and have shims in place again so you will have years of alignment capabilities)....OF...you install an off-set upper control arm shaft...which will buy you some time...depending on how much you drive it and how bad the roads are in your area. The only semi-permanent fix is installing the cross-shaft and brackets that connect the upper control arms points together. And this cross-shaft kit DOES NOT allow you to spread the cradle back to original configuration...it just keeps if from keeping any worse.
DUB
The "problem" that is inherent with the 63-82 Corvettes are that the engine cradle collapses over time. So the distance between your upper control arms begin to come closer to each other...due to bumps in the road, etc. In order to get the control arm to go back out as required....shims are removed to achieve this. When you have NO SHIMS in the upper attachment points. This is when either you have the cradle stretched back to its dimension (or at least to where you can install and have shims in place again so you will have years of alignment capabilities)....OF...you install an off-set upper control arm shaft...which will buy you some time...depending on how much you drive it and how bad the roads are in your area. The only semi-permanent fix is installing the cross-shaft and brackets that connect the upper control arms points together. And this cross-shaft kit DOES NOT allow you to spread the cradle back to original configuration...it just keeps if from keeping any worse.
DUB
