Chassis Guys, a little help please?

[Brad4406]

I'm welding in the coil-over shock crossmember. Prior to this, the ladder bar suspension was triangulated, which came out perfect, and the lower shock brackets are welded onto the housing the same distance on each side from the axle flanges. My problem is the upper shock brackets on the newly welded in crossmember. I triangulated the ladder bar crossmember prior to welding, but didn't triangulate the shock crossmember as the directions did not call for it. All the instructions called for was making sure the shocks were perfectly straight up and down. I made sure the shocks were fully extended used an angle gauge to make sure the shocks were perfectly straight up and down, but to make that happen, the drivers side shock upper brackets are 3/8" closer to the frame rail than the passenger side. Is this a big deal, or should I just get over it?

 

[johnparts]

Might be offset in the frame rails. I had 3/4 of an inch off center on my rear rails so I would measure exact center on the car and see if they are the same distance from dead center.

 

[Brad4406]

How do you determine exact center of the car?

I plan to get back out there and check the centering of the rear axle, but this time using the inside of each frame rail, not that I expect it to make a difference. I'll then check the shocks for straightness as they are used shocks and could possibly be bent, but I don't expect to find anything.

This totally took the wind out of my sails, what little bit I had. I was so proud when all of my previous measurements came out perfect.

 

[mopwr2004a]

the shock being closer to 1 frame rail then the other wont matter. as long as you can get your upper bolts in and out. to find the center of the car go off the wheel well openings. take you some plumb bobs on string and tape them to the over the center of each wheel opening. all cars have the engine offset to the passenger side of the car. that is why you got what you did measuring off the axle flanges. if you have not welded in any of your brakets take your top mounts and put them off each frame rail to where you can get bolts in and out. what type of shocks are you using?

 

[Brad4406]

what type of shocks are you using?

Koni Universal Coil-Over Shocks 82121126SPA1

The instructions for the coil-over shock crossmember said to attach the shocks to the lower brackets on first, so that's why I welded them on first. However, next time, if I ever do build another ladder bar or 4-link car, I may do it the way you described.

 

[69MOPE]

the shock being closer to 1 frame rail then the other wont matter. as long as you can get your upper bolts in and out. to find the center of the car go off the wheel well openings. take you some plumb bobs on string and tape them to the over the center of each wheel opening. all cars have the engine offset to the passenger side of the car. that is why you got what you did measuring off the axle flanges. if you have not welded in any of your brakets take your top mounts and put them off each frame rail to where you can get bolts in and out. what type of shocks are you using?

Never, ever take the measurements from the wheel well openings! I have seen up to an inch of differance side to side on many A-bodies. The center of the frame rails is the center of the car not the body.

 

[mopwr2004a]

Never, ever take the measurements from the wheel well openings! I have seen up to an inch of differance side to side on many A-bodies. The center of the frame rails is the center of the car not the body.

Yes you will see that if you measure from wheel well to wheel well. All the driveline is offset to the passenger side of the car.

You measure from outer body panel to the other outer body panel and that gives you thd truecenter of the car not the drivetrain. The engine, trans and rear have a offset. Not sure what you are refering to being up to a inch off.

 

[69MOPE]

The true center of the car is measured between the frame rails, not the body, which is very rarely the same on any two A-bodies. It sounds like he measured his center using the incorrect method and now the shocks don't line up because the rear suspension is centered between the quarter panels instead of the true center of the chassis.