REAR CROSSMEMBER SLOTTING
Slotting the rear crossmember the old-fashion way!
Article and Illustration by Kelvin Dietz

If you're looking for something a bit less involved than last issue's penultimate crossmember article, here are the steps showing how to slot a crossmember the original way.

Jack up the rear of the car and support it on jack stands.
Disconnect the brake cable at the backing plate for the rear drums.
Pull the cable lock clip and remove the cables from the control arm.
Disconnect the rubber brake line at the control arm.
Disconnect the outboard end of the halfshaft from the control arm.
Loosen the bolts holding the control arm to the crossmember
Remove the bolt or nut holding the shock absorber to the control arm.
Supporting the control arm on a floor jack, slip the shock absorber eye from the control arm
Slowly lower the jack and allow the control arm to pivot toward the floor.
Remove the coil spring. This can be a little difficult if the spring hangs up on the control arm or the body. Get everything loose and push down on the control arm with your foot. Be very careful as the spring will release with some force. (It's safest to stand to the side as you push down on the control arm.)
Remove the control arm-to-crossmember bolts and pull the control arm from car.
Repeat steps 2 through 11 for the other side of the car.
Slot the pivot brackets using the dimension shown in Figure 1. The easiest method for slotting the bracket is to cut them slightly undersized with an oxy/acetylene torch or a plasma cutter, and finish them to size with a high speed die-grinder or rat-tail file. Keep in mind that the cleaner and more accurate you make these slots, the better the inner sleeve of the pivot bushings will seat on the modified ears. The slots can be made entirely with a grinder or file but this is a long, tedious process. (Note: These dimensions are for a lowered car only. Slot the opposite way if your car has been raised for off-road use.)
Cut the pivot-bolt washers as shown in Figure 1. This is done to allow full upward adjustment of the inner pivot
Assemble in reverse order.
Notes Slotting a crossmember on the car is possible but it's a LOT easier if you already have it removed. To reinstall the springs, slide the springs onto the body seat and pivot the control arm up into it. Leave the pivot bolts in the stock position until the car is aligned. Tighten the bolts with the control arms up and the spring compressed. This will prevent distortion of the rubber pivot bushings that would occur if the bolts were tightened with the arms at full droop. If this can’t be done with the car on the ground, use a jack under the control arm to raise the car slightly off the jackstand to compress the spring. Do this one side at a time!
Camber and toe settings should be performed by a properly equipped alignment shop. Since they won’t have any specifications for setting the rear alignment on a 510, you will have to provide them. Camber setting from .5 to 1.5° negative are common, depending on ride height and intended use of the car. Toe should be set slightly in. 1/16" to 1/8" toe-in seems to work well to help combat the 510s inherent tendency towards "drop-throttle oversteer".

Consider having the large washers tack-welded to the crossmember ears after alignment. There is a tendency for adjustments to slip over time.


original article here -> http://dimequarterly.tierranet.com/article...r_slotting.html