Older High Mileage Jeeps - Before You Lift ItPosted in How To: Suspension Brakes on April 1, 2006 0) (
It has happened a million times. Somebody gets their lift kit installed and now the Jeep handles like crap or there's some new vibration, clunking, or other noise. If a shop did the install, it's the first to get an earful. But if it was an at-home job, the lift kit itself is most often wrongly blamed. The truth is that nine times out of 10 these problems stem from something that was wrong or worn out on the Jeep even before the lift kit was installed. This is especially true on older and high-mileage Jeeps. The new firmer bushings, springs, and shocks along with larger tires and wheels can produce more leverage and increased forces. This, in turn, accentuates or creates any handling problems that you may not have noticed or didn't originally have. So before you follow the footsteps of so many others and pull all your hair out, here are some things to inspect prior to lining up your lift or lighting up your local shop.
Worn out tie-rod and track-bar ends, along with larger tires can lead to wandering and even death wobble (violent, uncontrollable shaking of the front end). Check them by having a buddy turn the steering wheel from right to left slightly. Look for slop in the joint. There shouldn't be any. If there is, replace 'em. Worn or rotten boots like these aren't always a bad sign. In this case, these ends were fine, but the boots looked a little ragged.
Put the front axle of the Jeep on jackstands and grab a hold of the top and bottom of the tire. Check for slop by pulling and pushing alternately with your hands. Any movement here will likely be from the wheel bearings or ball joints (or king pins, depending on model). Isolate the movement by having a buddy inspect the knuckle and ball-joint area while you are grasping and moving the tire (see arrows). Worn ball joints should be replaced in pairs and king pins can be rebuilt and adjusted properly. Wheel bearings will either need to be repacked and adjusted or simply replaced if they are unit bearings.
Borrow a buddy to check your steering box for wear as well. Again, have him turn the wheel right to left while you inspect the sector shaft, pitman arm, steering box itself, and the mount (if equipped) for slop. Also check for cracks in the frame around the steering box. Any spooky-looking movement around this area is probably a little scary. Repair or replace as needed.
Cracked frames and loose spring mounts can cause sloppy handling. Inspect the large rivets used on some models and the welds holding the brackets to the frame. Fine rust dust around the rivets is a good indicator they are loose in their holes. Consider cutting them out and replacing them with Grade 8 bolts. Check very closely around the front of the frame where the steering box and springs mount. This is a notorious area for frame cracks on nearly all Jeeps.
Adding a lift kit to your Jeep doesn't necessarily provide a completely new suspension. In most cases, many of the old parts are reused. Depending on the lift kit, this could include much of the factory hardware, control arms, leaf springs, coils, shackle bushings, and track bars, among other things. Find out what's in the kit you're considering beforehand and inspect any of your factory parts that may not be replaced by the new lift kit. They could damaged, sagging, or way past their prime.