tom3holer

First off thank you all for you advice on my many questions about my newly acquired Wj.
It is a 1999 4.7 Limited with 71K miles one owner and in very nice shape rust wise for w Northeast truck.
One issue I have is the handling, I have replaced all the shocks and the rear upper and lower rear control arms.
Its a bit hard to explain but it seems to wobble on bumps in the road. It kinda rocks back and forth more than I think is normal.
I have looked at the front control arms and they seem to look OK with a pry bar don't seem bad, What are the indications of a worn out front end? The age is more of an issue than the age. I don't know the maintenance history so don't know if they have been replaced.
They are rust free if that is any indication.
Any thoughts greatly appreciated.

dave1123

At 71K, these shouldn't be a problem yet, but you should check the ball joints, wheel bearing hubs, steering linkage ends, and track bar. The track bar holds the front axle centered from side to side under the frame and any wear in the bushings can cause a wander by allowing the axle to move side to side. I would suspect the lower ball joints because they are not greasable and support all the weight of the front end.

Before I did mine, if you hit a bump just right, the jeep would just about change lanes! After I replaced all 4 ball joints and wheel hubs, it tracked like it was on rails!

If the body is rolling on corners, you should look at the sway bar links. When everything is right, a WJ handles like a sports car, flat and stable on corners with no body roll. If you know what you're doing, you can actually drift it and maintain control. I am amazed how well a 4000 lb jeep will corner! I had a 67 Camero that was set up for gymkhana and autocross so I have experience driving like that.

tom3holer

Dave,
Thank you for the input. This does not handle like a sports car. The rear upper and lower control arms and drag links were just replaced along with all shocks. It doesn't wander, its more like rocks back and forth, more than any other vehicle I have driven, slightly when going over a bump in the road.
I would suspect the rear links if they were not just replaced by my mechanic. I do have some play in the steering box which I plan to adjust this morning and see if that might be it. Will check the rest of the front end also.
Thank you again,
Tom

tom3holer

I just thought of something I forgot to mention.
I did just replace the shocks with Gabriel Proguard shocks and do hear a thud in the rear when going over bumps. The shocks that were on it had the Chrysler logo on them so I imaging they used the tapered bolt. The problem was/is there was no color on either of them. Just reread the thread that deals with that and wonder if that might be it. Went to Home Depot yesterday and bought all new hardware and will do that today also.

dave1123

You can do what you want because it's your jeep, but I wouldn't do anything with the adjusting nut on top of the steering box. That's only to limit the vertical motion of the sector gear and will not tighten up the backlash. You've got to remember worm and sector steering isn't as positive as rack and pinion and there will be some motion in the steering wheel that doesn't do anything. If it gets to be a lot, the steering box needs to be replaced.

When you say "rocks back and forth" do you mean body roll or changing direction?

At one point, my WJ was wagging it's tail like a dog. If you hit the gas, it would pull right, hitting the brake and it would pull left. Driving down the road you could feel the rear wagging back and forth. That turned out to be the rear lower control arm bushings steel cases had rotted out allowing the rubber to move around. You just replaced the arms so this wouldn't be your problem. I did massive surgery and replaced all 7 control arms and the track bar at that point.

I never had a problem with anything on my suspension until about 160K miles, so I don't understand why yours has these problems at only 71K.

HP2

...or is it porpoising (rocking front to back)?

CTarna

Sway bar/links?

4.3L XJ

Back and forth, I would do the standard death wobble check. Have someone rock the steering wheel back and forth while the engine is running. Check all joints for movement in them, especially that track bar bushing

tom3holer

The back and forth movement is side to side. It is short and kinda quick after a bump or rough part in the road. It just rock side to side slightly several times not like the usual once or twice. It seems like a rear end problem and the steering is tight with no hint of wobble. I did look at the front end with it n the lift and there was very little to no free movement except for the steering/pitman arm. I was under the impression form reading that that allen screw was to take up slack in the gearbox. I did adjust it slightly, maybe 5-10deg and it made a very noticeable difference in the free play in the steering wheel of which there is none noticeable now.
The rear end has all just been replaced with new links/bushings and control arms and shocks. It is much better than before but still kinda odd. My mechanic that I took it to for the rear control arm work make an observation. He said did I notice the springs are all fairly new?
I had noticed but thought nothing of it. He said that may have something to do with it.

IStoleIt

If the springs look new, maybe they were replaced/lifted. If the previous suspension was sagging with age, then suddenly raised, it will have changed the angle and weight on the track bar. A rear track bar thats loose will definitely cause this back and forth. Check for the mount holes to be oval-ed out or bad bushings. Check the L-R alignment of the rear axle(make sure its sticking out the same distance on both sides).

dave1123

AGAIN, we're talking about a rear 3-link suspension that doesn't have a track bar. How do the rear sway bar links look?

If the suspension HAS been lifted, you may need a spacer under the differential ball joint mount.

tom3holer

The suspension has not been lifted and the sway bar links have been just been replaced. Been driving ot more the last couple of days and its much better with the new rear 3 link suspension. I did get new hardware for the rear shocks and will replace that in a day or so.
As an FYI I bought the Addco 1" sway bar thinking it might help. It is a newer version with no zerk fitting as the bushings are said to be self lubricating. The bracket slots were no wide enough so I had to file them quite a bit. It seemed that the bushings protruded to far below the 90deg bend in the brackets as I looked at it. When bolted on I could not mpve the bar at all. Removed it and put the old one back on. I emailed Addco and am awaiting a response.

dave1123

With the new springs I thought it might have a 2" lift or an "Upcountry" suspension which is about 1.75". Just trying to cover all bases. You should be running 35 lbs tire pressure.

My 67 Camero had 2 Addco swap bars on it. 1.125" front and 7/8" rear. I kept breaking the rear links! I also had the 396 3-leaf rear springs on it from Dayton. 12.02 second 1/4 mile and kept up with the 'vettes in gymkhana. BUT it had 4-wheel drum brakes! It also had the "rally" suspension with only 5" ground clearance. Best car I ever owned for it's intended purpose, GOING FAST! SHP 350, Muncie 4-speed and 4.10 Posi rear.

As I said before, the WJ handles remarkably well for a 4000 lb vehicle with 9" ground clearance. The main reason for that is the double-solid-axle platform. I'm also rolling on 245/70R16 Cooper Discoverer AT3 tires.

HP2

Springs take the load of cornering and bumps. Shocks control how quickly those loads are absorbed and dampened. If you hare experiencing a quick side to side rocking after hitting a bump, the shocks are not controlling the springs adequately. Additionally, because the '99 GCs used live axles as opposed to independent suspension, there is a certain degree of opposing tire deflection when one side is bumped.

You've replaced shock, so dampening should be adequate. You have also replaced bushing and noted that you have all new springs. All of this in a vehicle with 71k miles seems very suspect to me. Mine has 301k on it. I'd expect to find worn out or replaced parts. I have to wonder if at least one or at worst several things are at play here; 1) you vehicle has a inherent defect that the previous owner could never correct hence all the new parts. 2) the previous owner stepped up all the spring rates and your OEM rated replacement shocks do not have correct valving in them to control the new rates. 3)Your impression of the vehicle's rocking is biased by previous experience in different vehicles.

dave1123

Bingo HP2! You may be on to something! I thought it very unusual for all those new parts in a low mileage car.

tom3holer, in my opinion you should have the alignment checked on all 4 wheels. You may have a rear thrust angle problem causing the jeep to "dog track", that is the rear axle not following in the same tracks as the front end. That would cause a sideways motion every time the rear wheels leave the ground, as in over bumps.

There is one other thing I thought about. If you have QuadraDrive, the rear differential may be locking up unexpectedly, causing a torque shift over bumps, but that's a long shot, sort of out of the box.