I just finished installing the new Atlas and now I'm at the point of adjusting the rear axle. Now I could just throw a couple of shims in(whatever I figure the degree to be) and call it a day, or I could take the whole rear end apart order new leaf spring perches and reweld everything up. Right?? So I'm looking at a couple of hours for shims and probably a couple of days for the tear down, wait for shackles to arrive in the mail, and then re-weld.

So I did a search and found nothing that was answering my question.

Is it bad to run shims?? If so why???

there is a place on moner circle rancho crodova, that has steel shims and spring mounts,
check out www.rubiconexpress.com

Thanks for the response. I've used many of their products.

I just finished installing the new Atlas and now I'm at the point of adjusting the rear axle. Now I could just throw a couple of shims in(whatever I figure the degree to be) and call it a day, or I could take the whole rear end apart order new leaf spring perches and reweld everything up. Right?? So I'm looking at a couple of hours for shims and probably a couple of days for the tear down, wait for shackles to arrive in the mail, and then re-weld.
So I did a search and found nothing that was answering my question....What is/are the negatives of using shims over cutting and re-welding the spring perches??

I can't think of any con's unless you get ridiculus and stack a bunch of them.
I've heard a lot of bad stuff about Alum shims but I've never seen a problem.
Pro's
They allow you to change your angle without rewelding the perches everytime.
Millions in use and I've never seen a failure (caused by the shim).
I cut my lift block to the angle I wanted, twice to get it right!

The RE degree shims are made out of cast aluminum - they work, but they eventually turn to mush. When you pull the axle U-bolts tight, the degree shims form to the spring shape which is somewhat curved - this distortion of the thin casting causes hairline cracks to develop. These cracks collect moisture and various road chemicals that cause the aluminum to deteriorate. Get a set of steel shims, they're a bit more expensive, but they form without cracking and will last as long as your springs.

When you've pulled the U-bolts tight enough to form the degree shims, make sure you torque them to the proper specs.

Get a set of steel shims, they're a bit more expensive, but they form without cracking and will last as long as your springs.

I would agree with this. Really the most reliable repair is to re-weld new perches, but you can probably get away with shims, especially if the shim angle is 5 degrees or less. Get the steel ones and after you have them installed, stitch weld them to the existing spring perch to keep it from moving around and squirting out.

This is the info that I was looking for. Thank you. I will look into some steel shims.

:grinpimp:

ttt

Get the steel ones and after you have them installed, stitch weld them to the existing spring perch to keep it from moving around and squirting out.

While this sounds like a stronger solution, the shim welded to the hanger would make it rather difficult to remove the spring if needed, since the shim is supposed to be attached to the spring with the centering pin. Just food for thought.

I run 5" long, 6 degree steel shims, and there is absolutely no issues with it,
Your U' bolts are tight, aren't they. If not, then you have more to worry about than whether you run a degree shim or not.

A steel shim is nothing more than a short thin leave in your pack.
Like I said, if you have a problem with it, it originated somewhere else.



Doug

Screw it....I just cut the old ones off and bought some new RE anti-wraps. So disregard.

Thanks all for the replies.


:flipoff2:

Brian, so is the Atlas in :D?

I would agree with this. Really the most reliable repair is to re-weld new perches, but you can probably get away with shims, especially if the shim angle is 5 degrees or less. Get the steel ones and after you have them installed, stitch weld them to the existing spring perch to keep it from moving around and squirting out.

I see you already found a different solution, but I'll add this. The best way to deal with shims is to bolt them into the spring pack. All you have to do is get a longer center pin and shims that are designed to be bolted on. For Sac peeps, I bought some from S&H on Arden in the past.
Travis..

Yep the Atlas is in.

And I cut and re-welded the rearend. No problems.