code4

iTrader: (30)

I'm installing LCA's, LCA relocation brackets, & SFC's. (UMI) I have the relocation brackets set in place & ready to weld. It is possible to move these a little, so how do I know these are set completely correct before I weld. What I did was measure from the oval slot on the stock bracket & made sure that both sides were exactly the same height. So should this be OK? I have the new lca's hooked up on both sides. Does it matter that the car is on a lift without any weight on the rear wheels?

2w0s060

You should only install one side at a time and weld one side at a time. The torque arm will hold the rear end from moving, however unbolting both control arms may cause the rear to shift slightly. Take one side and reinstall it back in the original location (stock). With that done now the other side you should be able to move the rear of the control arm up and down and see the arc and bolt pattern it should follow. My instructions where very detailed, if you read what I just wrote and follow the install instructions you should be able to get it.

WAHUSKER

iTrader: (4)

You have 2 axis to consider, verticle & horizontal (front to back, disregard side to side for now). I think as long as the bolt holes for the LCAs are the same distance from the axle housing on both sides, you should be good to go vertically.

I think how to get the correct front to back position on the bracket before you weld it is the question. Having weight on wheels shouldn't affect the position of the LCA front to back. I'm thinking hanging a plumb bob (string with a bolt tied to it) from the top bolt of the bracket & then making the bottom bolt the exact same distance on both sides would work. This alignment is critical since it will determine if the rear tires are pointed / tracking straight.

Once those 2 axis are correct, you can adj the PHR to center the rear end side-to-side. And having weight on wheels is required for SFCs. You want the frame un-sprung when you attach them in place.

kemmert

I just swapped lca's on my car, and the torque arm doesn't keep the rear end in place, the lca's do... I did one side at a time, and I was able to move the rear end fore and aft to line up the bolt holes...

code4

iTrader: (30)

As you can see in the pics, there is a bolt in the original mount hole & in the lca. So two bolt are holding it in place as per the instructions. I thought this would be pretty secure but the holes are oversized a little which allows movement up & down. I can take a mallet and knock them down another half inch lower than the pic. So I used a micrometer and set them exactly the same distance down from the slotted hole in the factory bracket & the bolts in the lca's are not in a bind. So hopefully its good & I will weld tonight.

On the SFC's I am thinking I will set the car down on it's suspension and weld a short bead in a few locations to hold them in place then lift again so I can finish it on the lift.

2w0s060

When I installed mine, by only unbolting one control arm at a time the axle did not move at all. I was able to swing the control arm in and out of the rear mounting point and have the hole still line up perfect. Now if you unbolt both the axle will move, however the torque arm has better hold then the old style GM upper control arms that allowed the rear to roll foward.

kemmert

I reckon the point I was trying to make, was that I wouldn't count on the torque arm holding the rear end in position accurately enough to weld in the lca relocation brackets, even doing one side at a time.

When I changed mine by unbolting one arm at a time, the bolt hole in the rear end's bracket didn't realign perfectly, I needed to use an alignment punch to align the holes. The rear end moved, not much, but it did move.....

code4

iTrader: (30)

OK I'm done welding them in. Here is what I did for piece of mind, I reinstalled the stock LCA in the stock hole on one side as recommended. Now I measured the center of the front and rear mounting bolt of the stock lca. Then measured the other side and made sure they were the same. Now once this was done to perfection the relocation bracket still had play up & down, I picked somewhere in the middle & welded the shiot out of it. Then used the same measurement on the other side for center to center of the stock lca mounting holes and the same height using the slot in the back as a reference point. Now they are dead nuts accurate & I am very happy. Now on to the SFC's tomorrow. Thanks for the advice.

99HOSS

sounds like you got your LCA re-lo brackets in OK. you'll feel that difference the first time you pull off the line or out of a turn.

for the SFC's, though, be sure your suspension is loaded, as if the car was on the road. There is significant movement in the entire car, specifically the front clip, when left to hang.

code4

iTrader: (30)

Will do, I am going to weld them in tonight. Going to set it down and weld a good bead on the areas that I can reach, then lift it again & finish up.

2w0s060

Did you get them in? How did it go?

code4

iTrader: (30)

It went very well! It looks great but I can't drive it due to snow so I will have to wait to test drive.