Yukon Gear & Install Kit Package Jeep XJ w/Dana 30 Front & Chrysler 8.25in Rear - 4.56in Ratio
A Jeep Cherokee XJ that has been lifted onto 31 or 33 in. tires almost always loses its pep. The 4.0 spins below where it makes torque, the automatic hunts between third and fourth on the highway, and first gear in low range is no longer slow enough to crawl. Swapping both axles to 4.56 is the standard fix, and this Yukon Gear & Axle package (part number YGK003) does it in one box for an XJ that has the Dana 30 front and the Chrysler 8.25 in. rear. It contains front and rear ring and pinion sets and the matching Yukon master overhaul kits, so new gears are not set up on old bearings.
A bigger tire works like a taller final drive: every turn of the axle moves the Jeep farther, so the engine has to work harder at every speed. Going from the common factory 3.55 or 3.73 to 4.56 restores roughly the engine speed the Jeep had on stock tires and multiplies torque at the wheels again. The XJ front is a reverse-rotation (high pinion) Dana 30, so it needs a reverse-cut set; the rear is the Chrysler 8.25 in. 10-bolt with threaded side adjusters instead of carrier shims. Both ratios must match exactly or the transfer case binds in four-wheel drive, which is why a matched front and rear package makes sense.
Look under the Jeep first. Many XJs left the factory with the Dana 35 rear instead of the 8.25, and this package only fits the 8.25. The axle tag on the cover and the RPO list are the quickest check, and our Chrysler 8.25 axle guide covers the visual cues. Read the ratio on the axle tag or the RPO list in the glovebox. If an axle is noisy rather than just geared wrong, rule out the transmission first with our transmission versus differential noise guide. To check that 4.56 suits your tire size, see the re-gear after bigger tires guide.
Listed for the 1991-2001 Jeep Cherokee XJ with a reverse-rotation Dana 30 front and a Chrysler 8.25 in. rear, 4.56 ratio. Yukon's product notes also name the YJ with the same axle combination. The important catch is the carrier: the technical note for this package says a Jeep currently running 3.55 (listed as 3.54) gears needs a new front carrier, because the 4.56 ring gear needs the deeper carrier used for 3.73 and up. Carriers are not included. If you are not sure what you have, send us your year and VIN before ordering and we will check it. If you want an even lower ratio for 33s and up, look at the XJ gear and install package in 4.88. More axle parts are in rebuild kits.
Plan this as two complete gear setups: pinion depth, pinion preload, backlash and carrier bearing preload on each axle, checked with marking compound. Yukon's set-up chart lists the Dana 30 at a 0.065 in. pinion shim starting point with 12-15 in-lb of preload on new bearings, and the Chrysler 8.25 (C213) at 0.030 in., 12-15 in-lb, 0.006-0.011 in. backlash, 55 ft-lb ring gear bolts and 60 ft-lb caps. The 8.25 sets backlash with threaded adjusters, so a Chrysler side adjuster tool saves a lot of frustration, and a pinion depth setting tool shortens the shim trial and error on both axles. A clamshell bearing puller pulls the Dana 30 bearings without damage.
Fill both axles with 75W-90 GL-5 gear oil, adding friction modifier if the rear has a clutch-type limited slip. Yukon lists 33 in. as its maximum recommended tire size for a Dana 30. Follow the new gear break-in procedure: easy driving, no towing for the first 500 miles, then change the oil in both axles. Recalibrate the speedometer for the new ratio and tire size.
| Brand | Yukon Gear & Axle |
| Part number | YGK003 |
| Fits | Yukon Gear & Install Kit Package Jeep XJ w/Dana 30 Front & Chrysler 8.25in Rear - 4.56in Ratio |
| Type | Differential Install Kits |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. YGK003 includes a Chrysler 8.25 in. rear gear set. If your XJ has the Dana 35 rear, you need a package built for the Dana 30 and Dana 35 combination. Count the cover bolts and check the cover shape, or send us your VIN.
If your XJ has 3.55 gears now, the package notes say you need a new front carrier, because 4.56 uses the larger carrier break. Carriers are not included. Tell us your current ratio and we will confirm what else you need.
A front reverse-cut Dana 30 ring and pinion, a Chrysler 8.25 in. ring and pinion, both in 4.56, and a Yukon master overhaul kit for each axle with bearings, races, seals, shims and small parts.
75W-90 GL-5 gear oil in both axles, with friction modifier added to the rear if it has a clutch-type limited slip. Change it after the first 500 miles to flush out break-in wear material.
Only if you have the tools and patience to set pinion depth, preload and backlash and read a gear pattern. Most owners have a driveline shop do the setup. A bad setup will whine or chip teeth quickly, no matter how good the gears are.
4.56 is a common choice for 31 to 33 in. tires on a 4.0 XJ. Yukon lists 33 in. as the maximum recommended tire size for a Dana 30 front.
