andrewdonald1

Gents: Middle of putting poly bushings etc through out the 04 C5Z.
Last night I started mounting back up the rear transverse leaf spring.
I decided to grease the outside of the transverse spring rubber bushings thinking that the bushings are 6 years old, might as well get rid of any potential squeaks.
Thinking a little more about it today, not sure if this is a good idea or not.

There are ridges in the upper and lower rubber bushings to hold it in place and it does clamp down pretty good.

Any comments? Should I pull the spring back out and use some brake cleaner and clean off the grease?

sperkins

You talking about the spring bolts at the control arm or the bolts that hold it to the cradle?

andrewdonald1

I am talking about the 2 rubber bushings itself that mount the rear spring to the rear aluminum cradle.

froggy47

The rectangular type bushings that wrap around the middle of the spring?

I don't think that is a squeak area, but I don't think that grease will hurt anything either, what is the torque spec on those?

andrewdonald1

yep the rectangular bushings.

46 ft lbs

davidfarmer

it should not be a moving part if you bent it properly during installation, ensuring it seated properly. However a little grease should not hurt anything

andrewdonald1

Now that is a interesting comment.
I just put it up into the female side of the aluminum cradle, then crisscrossed the final torquing of the bolts.
I haven't installed the ends of the spring to the lower control arms just yet.
Do I need to redo the installation into the cradle?

froggy47

Bent what David?

davidfarmer

you have to "straighten" the spring or it will not line up properly. As the spring curves, the rubber mounts bend closer together...you must compress the spring in order for it to seat properly. GM makes a special tool, but I've always just installed one side, then used the weight of the car to push the opposing side up.

Some OEM springs may line up without compressing them, but the many I've done have needed to be compressed slightly to get them to fit. A "straight" spring like VBP makes goes right in without any loading.

andrewdonald1

Excellent info David. I'll have to take a look at that.

So how exactly did you do it.

I am currently up on jack stands front and rear.
Front suspension is being disassembled now.
Rear: all I've got left to do is bolt up the springs to both control arms, install brake rotors/calipers on each side.

I am thinking for the rear:
[1] bolt up one of the two spring perches.
[2] use jack under bottom of opposite end of spring (I think its all metal sleeved at the end but I'll have to confirm that) and carefully lift up till I get it fairly straight then bolt up that side spring perch.
[3] Maybe before step [2] I should also bolt the spring to lower control arm on the same side of car as step [1].
Your thoughts?

davidfarmer

Your method sounds fine, that's the way I've done it. I don't know how you would "bolt" the spring to the control arm though. You just want to make sure the indentions on the spring mounts actually seat, not just jam the metal cover over them.

not for a C5, but an actual spring compressor

andrewdonald1

The side of the cradle mount that I was going to bolt up first, I would connect the bolt as well that connects that side of the spring to that side of the control arm.

From a safety perspective: I was thinking it may be better to have two points of contact with the spring on the opposite side that I would use the jack on - that's all.

andrewdonald1

Tried this method. Works great. However I think the spring bushings are slightly off (c-to-c dimension with respect to the c-to-c of the cradle). I tried flipping the swing arm around, and switching the lower clamps.
The grease I think helped it seat into the groves as the clamps were torqued down.

David: thanks for catching this for me.