Tilt to LR side after OME lift

redcrd · **Posted:** Tue Aug 30, 2011 8:35 pm

I installed OME springs and shocks today on my CRD. Previously I had Skyjackers, thinking the LR spring was starting to sag I ordered OME, but the problems is still there I have a 3/4" difference in height from LR to RR. If you stand behind the truck you see a tilt down on the LR side. Does anyone else have this problem or have an idea why the truck tilts on the LR? Thank you in advance.

retmil46 · **Posted:** Thu Sep 01, 2011 10:39 am

redcrd wrote:

I installed OME springs and shocks today on my CRD. Previously I had Skyjackers, thinking the LR spring was starting to sag I ordered OME, but the problems is still there I have a 3/4" difference in height from LR to RR. If you stand behind the truck you see a tilt down on the LR side. Does anyone else have this problem or have an idea why the truck tilts on the LR? Thank you in advance.

Hmmmm. Could be the problem is not with the springs or shocks, but with your suspension arms.

There is an upper suspension arm, shaped like a "V" or boomerang, that attaches to the top of the rear diff with a balljoint at it's "point", and to the body at the ends of it's "arms" with a rubber bushing. This upper suspension arm is supposed to control lateral (side to side) movement of the rear axle and keep it in line with the front.

There are also two lower suspension arms, one on each side, that connect the rear axle to the frame, and are where your shock absorbers attach to. These lower arms also use a rubber bushing at each end, and are designed to control vertical movement of the axle in conjunction with the shocks and springs.

Reading on other forums, it seems to be a common complaint from all years of KJ's, gasser and CRD alike, that these bushings and balljoint give out and throw off the rear suspension. On mine at 59K miles, I replaced the rear upper suspension arm - the balljoint that attaches to the diff was worn out to the point you could easily swivel it around with one finger. Many on other forums actually fill in the voids in the rubber bushings with windshield sealer RTV to stiffen them up and keep them from sagging, and I've seen pics where the diff balljoint had failed altogether and split apart.

First, I'd try measuring your ride height on each side at the springs per the FSM - basically, you measure from the bottom end of the rubber bumpstop inside the spring, to the bottom mounting plate for the spring - it should be 90 mm plus or minus 10 mm. If both springs are reasonably equal as far as ride height at the axle, I'd strongly suspect something is going on with your suspension arms.

Even if the springs aren't equal in ride height, the fact you've had two different sets of springs giving you the same lean to one side - very slim odds in my book that it would be bad springs given that - I'd still suspect the suspension arms as the main culprit.

geordi · **Posted:** Thu Sep 01, 2011 5:21 pm

Mitchell - I was just under my CRD today replacing the rear diff ABS sensor and I checked on everything I could. That ball joint seems solid, and I can't move it at all, but what I am finding is that the right rear hub is able to slide in and out maybe about 1/16th of an inch. This is making a low-frequency noise that I think I have been hearing as a sound short for a while now.

Any thoughts on how to cure it? I pulled off the brake disc and couldn't figure out how the axle is being retained without digging further into it... Which I'm not really ready to do until I know more about this. I know I still need the shocks, and I thought I saw the CRD sitting a little weird (low RR compared to LR) but that could also be the ground - I will check that again when I move it shortly. The suspension points all seemed solid though, and shoving on the tire with both rear wheels in the air (jacked from the RR body point for the lower control arm) did NOTHING. The wheels didn't shift at all, beyond that little bump of the hub.

retmil46 · **Posted:** Thu Sep 01, 2011 10:19 pm

Ball joint on mine felt solid as well, with the suspension arm still installed in the vehicle and sitting on the ground. That's the kicker - as far as I know, there's no real way to tell what kind of shape it's in, other than obvious catastrophic failure where it's leaking grease everywhere, until you pull the arm out of the vehicle.

Besides the balljoint, the rubber bushings at the body attachment points have metal jackets around the outside. The bushings were warped over to one side and the metal jackets were hitting hard against the body - thus I surmised I had a metal to metal "sound short", conducting gear noise from the rear diff to the cabin such that I was sitting in an echo chamber.

Installing the new suspension arm muffled the noise, but didn't eliminate it, so i knew I had to move on to the rear diff.

What kind of low frequency noise are you hearing? And under what conditions?

On mine, it started out faintly at highway speeds (50 mph and above in lockup), low frequency, sounding like a tire out of round/out of balance/with a flat spot, but none of the accompanying vibration you'd associate with a bad tire.

It gradually became louder, such that once above 50 mph pulling onto the interstate it was there all the time and quite obvious. I started suspecting it was the rear diff or driveshaft because as soon as you eased off the throttle - unloaded the drivetrain - it would completely disappear, even though I was traveling at the same speed. And it would become more noticeable when going uphill and having to give it more throttle. Per the FSM, that pointed to the rear diff.

It got to the point that it started becoming noticeable at street speeds (35 - 45 mph), and when coasting at street speeds you could barely feel a small "lope" to it, as if something was out of balance. By that time I'd been thru alignment, tires, shocks and springs, suspension arms, brakes, removed front driveshaft - only candidate left was the rear diff, especially since it had started leaking from the pinion seal.

From what I understand, the rear axles are held in by C-Clips inside the rear diff. No idea if the 1/16th inch play you had in the one hub is reason for concern. Best advice I could give would be to check with a reputable shop that's experienced with working on rear diffs and axles.

ATXKJ · **Posted:** Fri Sep 02, 2011 7:07 pm

Not redcrd's problem - but on testing the rear ball joint - this was another thread

SargeIndustries wrote:

Crawl under the vehicle and have someone rock the vehicle front to back hard and watch for movement on the upper ball joint. If it is worn, the whole rearend will rock or twist. I replaced the ball joint only to find out that it still rocked back and forth. Then I pulled the cast steel ball joint bracket and discovered the problem. The ball joint pinch bolt must not have been torqued properly from the factory. It was a mess! I ended up plunge milling it out to clean up the hole then made a bushing to drop in and bring the hole back to 21MM. Saved a $140...

(of course you could do the jeepster thing - and disassemble the entire rearend to paint & polish it.....link

geordi · **Posted:** Fri Sep 02, 2011 8:15 pm

The best way I can think of to describe the sound, is what it sounds like if you were to lock the deadbolt on your front door, but hold the knob-latch in so that the door could rattle in the holder. It sounds a lot like that to me, which is what made me think of the axle in the first place. I think it might be a normal sound, but since I am now hearing it transmitted through something else, it is actually audible. It doesn't seem to be audible on rough roads or on really bouncy pavement, but I hear it the most on the dirt / gravel road into and out of where I live, and on the cracked-concrete sections of paving in Downtown Savannah. Its almost like what I am hearing is the movement of the tire when the suspension DOESN'T need to react to the surfaces.

My plan right now for the weekend is to go back under there and specifically look for metal-to-metal on the ends of that arm and on the lower control arms while the CRD is on the ground. The lean I thought I saw was b/c of the ground and how it was parked, so at least that is one thing answered.

arengant · **Posted:** Fri Sep 09, 2011 8:01 pm

retmil46 wrote:

First, I'd try measuring your ride height on each side at the springs per the FSM - basically, you measure from the bottom end of the rubber bumpstop inside the spring, to the bottom mounting plate for the spring - it should be 90 mm plus or minus 10 mm. If both springs are reasonably equal as far as ride height at the axle, I'd strongly suspect something is going on with your suspension arms.

Even if the springs aren't equal in ride height, the fact you've had two different sets of springs giving you the same lean to one side - very slim odds in my book that it would be bad springs given that - I'd still suspect the suspension arms as the main culprit.

If the ride height is equal on both sides, I.E. 90mm, then how could the jeep STILL be leaning? Can the suspension arms make the jeep look like it's leaning to one side but still have the springs at the same length?

Tilt to LR side after OME lift

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