Front A arm pivot cross shaft question
Thread Starter
Instructor
Joined: Dec 2001
Posts: 101
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From: Manitouwadge Ontario
Front A arm pivot cross shaft question
I had bad luck with some poly bushings I ordered that do not fit so I am reverting to rubber. The poly bushings would have allowed the shaft to rotate to any position but the rubber bushings will not. I understand the rubber in the bushing is designed to twist as the A Arm moves up and down.
What is the initial position of the pivot cross shaft when pressing it in so as not to pre-stress the bushings too much. Should the bolt holes be in the same plane as the arm?
What is the initial position of the pivot cross shaft when pressing it in so as not to pre-stress the bushings too much. Should the bolt holes be in the same plane as the arm?
Racer
Joined: Mar 2001
Posts: 438
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From: Houston, Texas
Re: Front A arm pivot cross shaft question (Tired74)
Not sure what "in the same plane as the arm" means, but you should put the full weight of the vehicle on the suspension before tightening the a-arm bolts. Including the bolts on each end of the shaft to avoid breakage.
Thread Starter
Instructor
Joined: Dec 2001
Posts: 101
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From: Manitouwadge Ontario
Re: Front A arm pivot cross shaft question (noskillz)
Thanks for the tip. What I mean is if I insert a bolt in the bolt holes for the top pivot arm should they be horizontal and along the same line as the top surface of the A Arm or should there be some angle of installation. In other words would the flat surface where the bolts go through be perpendicular or 90 degrees to the top surface of the a Arm. I am worried if I install the pivot shaft such that i need to force the Arm one direction or the other that this will pre twist the bushings and greatly reduce their life. I could not find this spec in my AIM
Burning Brakes
Joined: Nov 2001
Posts: 1,191
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Re: Front A arm pivot cross shaft question (Tired74)
I think I know what you mean. You're talking about the upper A-arms, and you have to pre-torque the end caps because you can't do it in the car after attaching the a-arms.
After looking at mine installed and sitting with the wheels on the ground, the bolt holes in the cross shaft appear to point to the boot on the ball joint, and the a-arm appears to arc over the line drawn between the holes in the cross-shaft and the ball-joint boot.
FYI - I noticed that one end-cap was loose - luckily one that I could tighten, the driver-side rear.
After looking at mine installed and sitting with the wheels on the ground, the bolt holes in the cross shaft appear to point to the boot on the ball joint, and the a-arm appears to arc over the line drawn between the holes in the cross-shaft and the ball-joint boot.
FYI - I noticed that one end-cap was loose - luckily one that I could tighten, the driver-side rear.
Intermediate
Joined: Oct 2003
Posts: 49
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From: Prince Frederick MD
Re: Front A arm pivot cross shaft question (Tired74)
I recently rebuilt the front end on a 75. Should I wait to have the full weight on the car before I tighten the bolts on the a-arm shafts? You couldn't possibly mean the shaft mounting bolts - the two that attach the a-arm to the frame? Or do you mean the shaft end bolts that have the big washers on them and secure the bushing? I used polyurethane bushings and the shaft turns relatively freely inside the bushing.
Race Director
Joined: Feb 1999
Posts: 16,978
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From: In Dreams There Is Truth Ohio
Re: Front A arm pivot cross shaft question (Tired74)
If you are installing the rubber bushings, if memory serves me correct, the shaft will rotate if the a arms have not been installed. You can then rotate the shaft to the correct position so the mounting holes line up with the bolts. If the shaft is stubborn, you can use vice grips, but the shaft should rotate.
