Stock-height YJ runs Bilstein 4600 or Rancho RS5000 in factory length. A 2.5-inch lift runs a slightly longer shock; a 3–4-inch lift wants the Bilstein 5100 with 28.44-inch extended / 16.97-inch collapsed travel. Match shock length to lift height — too short bottoms the shaft, too long limits droop.
The YJ uses four shocks — eye-loop on the bottom and a stem with two nuts on the top. They're straightforward to access, straightforward to swap, and probably worn out on any YJ that hasn't had them replaced in the last 80,000 miles. A worn shock won't pass a "park-the-truck and shove the corner downward" bounce test: if the truck oscillates more than one and a half times before settling, the shock is shot.
Bilstein 4600 monotube is the safe default for a stock-height YJ. Bilstein 5100 is the same valving in a longer body for lifted trucks and gives a noticeable improvement in trail manners. Rancho RS5000X is the budget alternative — softer, more comfortable on-road, less composed at speed. The expensive options (Bilstein 7100, King 2.0, Fox 2.0) only make sense on a built rig that sees triple-digit trail speed; on a daily-driven YJ they're overkill.
Length is the part nobody gets right. A stock YJ front shock is **24.5-inch extended, 14.5-inch collapsed**. A 2.5-inch lift wants roughly **27-inch extended, 16-inch collapsed**. A 4-inch lift wants **28.4-inch extended, 17-inch collapsed** — that's the Bilstein 5100 24-064576. Run a shock that's too short and you'll bottom the shaft on every long droop, which destroys the seal and dumps oil within months. Run too long and you cap suspension travel before the axle is at full extension. Measure your current suspension at full droop (let it hang on the springs only) and order shocks rated for that extended length plus an inch of margin.
The eye-loop bushings deserve a fresh squirt of silicone or rubber lube before final torque. The stem-style upper mount has two nuts — torque the bottom (inner) nut against the shock stem to **35 ft-lbs**, then snug the locking nut on top. Don't over-torque the eye bolts; the rubber bushings should compress only slightly when you tighten, not deform into the metal sleeve.
| Part | Vendor | Est. price |
|---|---|---|
| Bilstein 4600 stock-height shock (front, YJ) | Bilstein | ~$75 |
| Bilstein 4600 stock-height shock (rear, YJ) | Bilstein | ~$75 |
| Bilstein 5100 3–4" lift front shock (YJ) | Bilstein | ~$95 |
| Rancho RS5000X 2.5" lift shock set (YJ) | Rancho | ~$220 |
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.