So I decided to muck with suspension components after telling myself I wouldn't. I needed to— The rear springs were saggy and only kept the tires from rubbing with a crap block lift. So I installed some Rancho HD springs, which give about a 1.5" lift. The ride height now is roughly the same, maybe just a tad higher now that the springs aren't inverted…

My problem is the small amount of vibration I had before (mainly at 70+) is much, MUCH worse, which led me to a couple old threads about matching the yoke angles. I'm thinking this is the problem.

I have only the above experience with suspension, and I know I did something wrong, or just didn't do something when installing— I went one leaf at a time, but I think my rear axle clock is off:

This is about what it looks like. I don't have an angle finder and haven't been under it proper since installing the new springs. I say about because it's approximate. The t-case is angled downward slightly, but the axle is steeper.

How do I remedy this problem?


Thanks

 

I am assuming you dont have a SYE since you didnt bring it up. If correct, then this is what you need.

 

Shims between the axle & spring pack.......have to measure to see how much tho....or buy a bunch & try them.

 

Correct—I don't have an SYE. I was afraid I'd have to shim it. The paperwork that came with my springs mentioned it, but made it sound like that was for higher lift kit sets or something.

 

Something like this adequate?
https://www.harborfreight.com/dial-g...der-34214.html

Also, forgive the novice questions— do I need to worry about there not being enough of the stud on the spring pack to go through both the shim and the spring mount on the axle? Does the shim bran need to match the springs I have?

 

You may need longer bolts to hold the spring pack together

Were there any angled shims on the bottom of your spring pack ?

 

I didn't see any in the boxes
https://www.quadratec.com/products/16033_018.htm
https://www.quadratec.com/products/16035_003.htm
Nothing noted on the parts list, so I'm confident in saying no, there weren't any. The instructions mentioned different kit numbers for shims, but at only 1.5" You'd think it would sit fairly normal, but then again, not OE springs…

 

Sometimes the shims are bolted to the bottom of the spring...not a separate part

huh...sell as a 1.5" lift spring, but it shows a lift range of 0-2.5"

 

So Six States took a look at it and it's 6º off. They recommended a spring/fab shop in the area that can get me the size I need in steel. The other option was re-welding the mounts, which they can't do for about 2-1/2 weeks, and will cost me more than shims, I'm assuming.

Here's my next question:
Do I need anything besides just get the shims, and install them at this point? In my head the nub/pin on the spring pack isn't going to be long enough to go through a shim and into the mount. I looked up a 6º shim's specs and it says 0.61" on the thick end. That doesn't sound like the pin will go through. How do I go about making sure I'm doing this right from here on?

Do I take the bottom-most leaf off to give me extra length on the pin? Treat me like an idiot, because I'm quite ignorant when it comes to this aspect of wrenching.

 

You clamp the spring together with c-clamps, unscrew the center bolt, run it thru the shim, then thru the spring pack, and re-tighten.

You may need a new set of center bolts, and once you bolt it all together, cut them to length

 

Does this need to be done with the springs OFF the jeep? Please say no.

Obviously, the axle needs to come off, but do I need to remove the springs from the chassis?

 

No, but it is easier....you WILL have to unbolt the axle from the spring tho, and shocks from the axle, etc.......with enough room to fit your hand between the axle & springs

 

On the jeep is fine. Do one side at a time.

 

Here's a thought, and again, this is based on nothing kinda—and I'm not trying to be an askhole, I'm just looking for the easiest solution.

I wasn't thinking about anything but getting the friggin springs in and on (it took me an inordinate amount of time and I was fed up). Can I loosen the u bolts just a bit and use a bottle jack and some wood to manually clock the axle?

I'm thinking about it over and over, and unless the mounts were re-welded for a drop, why the hell would they be 6º off true?


edit: what I'm getting at is, in my rush to just get the job done, could I have just missed the fact that manually clocking it to a more nominal angle is part of the process?

 

When you put the lift on, the location of the axle changed...it moved down by ~3" or so....and when it moves down, it also moves closer to the front of the wheel well, and it rotates the pinion up. Your perches have not been cut off & re-welded.

The axle is attached solidly (as in no shackle) to the frame by the front half of the leaf spring...and that means the whole axle & spring assembly rotates around the forward bolt as it goes up and down.

As the axle moves up (without flattening the leaf spring), the pinion will rotate down & back.......as it moves down, it will rotate up & forward.down. The angle between the pinion and the leaf spring is fixed, and if you change the leaf spring angle relative to the transfer case, the pinion angle will change just as much, but the pinion will still be in the same place relative to the leaf spring.

You could do some theory to practice here if ya want to see yourself what happens.
1) jack up the truck pretty high and put the body on jackstands
2) with the jack under the rear axle, remove the lower shackle bolts on both shackles, and unbolt the lower shock mounts
3) now, you can slowly lower the axle and watch how the relation between the pinion angle and transfer case changes as the axle drops, you will see the axle move forward and the pinion rotate up relative to the body as the axle drops
4) just make sure you don't mess up your brake drop line


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