The TJ introduced coil springs over the leaf-spring YJ, dramatically improving ride and flex. It's a legendary platform — but 20+ year old Jeeps come with 20+ year old problems. Here's what to watch for.
A violent, uncontrollable shaking of the front end typically triggered above 45–55 mph, often after hitting a small bump. Caused by worn steering and suspension components — track bar bushings, ball joints, tie rod ends — that allow resonant oscillation to amplify dramatically.
TJs from rust-belt states can develop severe frame corrosion, especially around the rear tub mounts, control arm mounts, and outriggers. Severe rust can compromise structural integrity and make repairs more expensive than the Jeep's value.
The beloved 4.0L inline-six is bulletproof mechanically, but its valve cover gasket, oil pan gasket, and rear main seal are notorious leakers on high-mileage examples. Oil consumption and minor seepage are almost universal past 100,000 miles.
The 4.0L's plastic cooling system components — thermostat housing, radiator end tanks, and bypass tube — become brittle with age and heat cycles. Failures can happen suddenly and cause overheating leading to head gasket damage.
Original soft tops on TJs are well past their useful life. Window fogging, zipper failure, and torn seams allow water intrusion — a significant issue that can cause floor rust and mold.
The NP231 transfer case can develop vacuum hose deterioration leading to 4WD engagement problems. The front axle disconnect system on some trims relies on vacuum and commonly fails with age.
Manual transmission synchros — especially 2nd gear on the AX-15 — wear out over time, causing grinding on shifts. Often made worse by low fluid or extended service intervals.
The wiper pivot bushings and linkage on TJs wear out, causing wipers to park incorrectly or move erratically. A common and inexpensive repair often overlooked during ownership.
On manual-equipped TJs, the clutch master and slave cylinders are a known wear item. Symptoms include a spongy clutch pedal, difficulty finding gears, or clutch not fully disengaging.