To the racers who have redone their rear suspension with full race stuff, anti roll bars, 4 link, ladder bars, or just adjustable upper & lower control arms with heim joints, I have this question; Did you find that one side is adjust differently than the other to get rear "squared up" in the car?? I'm still in the process of redoing my rear suspension with HRpartsNstuff ultimate uppers, and wolfecraft adj. lowers, and the HR anti roll bar. I'm trying to get my pinion angle set, and the rear end squared up in the frame by adjusting the lowers. I talked to Bobb M. about this last week, he said to get the rear square in the frame, measure cross side (X) from front lower ball joint to center of the aft bolt of the lower control arm. I did this a few times, and rechecked my measurements a few more times, I did set the rear evenly by measuring this way, but also did a measurement "on side" from front lower ball joint, to the same side aft bolt of the lower control arm, and also measured each lower control arm after adjustment, just to see where they were, and they are not even, about a 3/4 inch between each side. Just wondering if anyone out there has seen this with their car. I'm not super concerned, the rear should be "square" and "even" regarding the front end due to "X" measuring... I have owned this car for 24 years, and bought it from the 2nd owner, who worked at a nursing home and got it and turned it from the origional owner, and it has only been in a slight fender bender, had to replace the drivers fender, and I know it didn't tweak the frame. So maybe the factory built it alittle "off", or the drag racing for the past 17 years has taken it's toll. What have you seen or come across?? Thanks, Gary G.
Gary, What was suggested to you is just a ball park type deal.. To properly square the rear diff, you need to do the following. 1. Jack the car up, and level it, side to side, front to back. 2. using factory fixed points on either side of the frame, establish a centerline, and use a piece of string taped to the floor, to show this centerline. 3. Now, about 2 feet in front of the rear diff, you need to establish another line, 90* perpendicular to the centerline, the width of the car. Use a carpenter's square for this. Now that you have those.. Using a plumb bob, establish two marks on the floor, that correspond with the rear axle centerline on each side. Simply hold the string of the bobb, on the center of the axle shaft, at mark the floor where the pointer on the bobb indicates. 4. using your string again, connect the two points. 5. Measuring between the rear axle centerline and the perpendicular line will tell you if the rear end is square or not, and how much it is off. 6. Once you establish that, also measure vertically to your rear suspension mounts, to make sure the heights are the same. Here's a bit of a visual for you. http://www.trishieldperformance.com/72_gs_455_tube_chassis_car.htm In many of the pictures, you can clearly see the centerline, as well as the other reference points. This allowed me to diagnois and "fix" a previously built car, that never went straight a day in it's life.. When we put it on the alignment machine after it was done, the rear end thrust angle was 0.0*.. the alignment tech was amazed.. new cars typically are not that square.. That car, thru 5 years of running low 9's and high 8's, never went anything but straight, unless it spun the tires. It's really not difficult, just takes some time, some simple tools, and a good flat surface. Make sure it's level, suspension points at different heights are just as a big a concern as out of square. JW
