Stock XJ Saginaw 800 box develops sloppy on-center play. ZJ (5.2/5.9 V8) and Dodge Durango boxes are both proven bolt-in upgrades — stronger sector, better feel, cheap from salvage.
The factory Saginaw 800-series steering box on the XJ develops slop with age — measured as steering wheel deadband on-center exceeding 1-2 inches. Symptoms: vague on-center feel, wandering at highway speed, contributor to death wobble.
**Step 1 — Try box adjustment first.** There is a sector-shaft preload adjustment screw with locknut on the top of the box. Back off the locknut and tighten the screw 1/8 turn at a time, retest. If preload alone fixes it, save your money.
**Step 2 — Donor box swap if adjustment doesn't hold.** Two well-documented bolt-in options:
**ZJ V8 steering box (Mopar 52088033):** The 1993-1998 Grand Cherokee with the 5.2 or 5.9 V8 used a larger sector shaft Saginaw box that bolts to the XJ frame with an identical mount pattern. Slightly different ratio than stock XJ and stronger overall. Junkyard cost $50-100; new aftermarket $250-400 (Crown 52087905). PS pump lines may need adapter fittings — the ZJ pressure port is slightly different.
**Dodge Durango steering box (1998-2003):** Less commonly discussed but equally valid. The Durango uses a similar Saginaw-based box with a larger piston cylinder and heavier duty case, resulting in more power assist. Bolts in directly to XJ frame, same splines, same procedure. Often cheaper or more available than a ZJ box at salvage yards. One caveat: some early Durango units have a raised cylinder cap flange that limits full lock-to-lock at axle flex — pull the spacer inside the piston cylinder if you lose turning range after the swap.
**Steering shaft:** Pair either box swap with a Borgeson 000937 OE replacement shaft, which addresses the other common death wobble contributor (worn U-joint in the factory shaft). Alignment recommended after any steering box replacement.
| Part | Vendor | Est. price |
|---|---|---|
| ZJ V8 steering box | Mopar/Crown | ~$350 |
| Dodge Durango steering box (salvage, 1998-2003) | Salvage yard | ~$50 |
| Borgeson steering shaft | Borgeson | ~$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.