The 8.25" Chrysler rear was optional/standard on 1997-2001 XJs with V8 packages and certain trims. Significantly stronger than D35; 29-spline shafts and a real ring gear.
The Chrysler 8.25" axle was introduced as a stronger rear option in the 1997+ XJ. It has an 8.25" ring gear, semi-floating non-c-clip 27-spline (early) or 29-spline (later) shafts, and a more robust housing. The 8.25 is significantly stronger than the D35 — a real step up.
Gear ratio identification: the 8.25 came with 3.07, 3.55, or 3.73 gears in XJs (rarely 4.10). Check the build sheet sticker on the driver door, or pull the diff cover and count teeth (ring/pinion). Tag on the housing also identifies the ratio.
Shaft variants:
Identifying which 8.25 you have: count splines on the axle shaft end (need to pull a shaft) or look at the spline diameter. 29-spline is visibly larger.
Vs D35:
Vs 8.8:
Many builders who have a stock 8.25 leave it alone and run 33s without issue. Adding a locker, chromoly shafts (29-spline), and disc brake conversion makes a 33-35" tire rear axle for less than swapping to 8.8.
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.