Yukon Gear & Install Kit Package Jeep JL Non-Rubicon D44 (M220) R / D30 (M186) F - 4.88 Ratio
A Jeep Wrangler JL Sport or Sahara that went to 35 in. or bigger tires usually feels flat on the highway, hunts gears on hills and crawls too fast off-road. Re-gearing both axles fixes that, and this Yukon Gear & Axle package (part number YGK079) puts 4.88 gears in a non-Rubicon JL that has the Dana 30 M186 front and the Dana 44 M220 rear. It includes front and rear ring and pinion sets plus the matching Yukon master overhaul kits in one part number.
Taller tires act like a higher gear, so the engine sits below its torque band and the transmission downshifts constantly. A numerically higher ratio such as 4.88 brings engine speed back up at a given road speed and multiplies torque at the tires. Both axles must match exactly, because the front and rear are locked together in four-wheel drive. The JL front Dana 30 uses a reverse-cut gear set, while the M220 rear is a standard rotation 220 mm axle with 32-spline shafts. Yukon pairs each set with its own master overhaul kit so you are not reusing tired bearings under new gears.
This is the step that saves money: check which rear axle your JL has. Base Sport and Sahara models came with the smaller Dana 35 M200 rear, and many tow or gearing packages got the Dana 44 M220. Run the VIN or check the window sticker, and see our Dana 35 vs Dana 44 guide for the visual differences. If yours is the M200, this kit will not fit; look at the JL non-Rubicon Dana 35 rear gear package instead. To pick the right ratio for your tire size, read our re-gear after bigger tires guide.
Built for the 2018-and-later Jeep Wrangler JL non-Rubicon with a Dana 30 (M186) front axle and a Dana 44 (M220) rear axle, 4.88 ratio. It is not for the Rubicon, which uses a Dana 44 M210 front, and not for JL trucks with the Dana 35 M200 rear. The kit does not include carriers, so your existing carriers must accept a 4.88 ring gear; if you are unsure, send your year and VIN and we will confirm before it ships. If you would rather stay at a milder ratio, the same package comes in 4.56 for the JL non-Rubicon. More axle parts are in rebuild kits.
Each axle is a full gear setup: pinion depth, pinion preload, backlash and carrier preload, checked with marking compound. Yukon's set-up chart lists the D30 JL with a 0.050 in. OEM pinion shim, 15-20 in-lb new pinion preload and 70 ft-lb on the ring gear bolts and caps, and the D44 JL rear (220 mm) with a 0.045 in. shim, 12-19 in-lb preload, 110 ft-lb ring gear bolts and 70 ft-lb caps. Backlash is 0.006-0.011 in. on both for a standard cut gear, tighter for 2-cut sets. A pinion depth setting tool and a bearing separator puller make the bearing work manageable.
Planning a locker too? Do it during the re-gear, while the carrier is out: the Eaton ELocker for the JL Dana 44 M220 drops in at the same time. Fill with 75W-90 GL-5 (with friction modifier if the rear has a factory limited slip), follow the break-in procedure with an oil change at 500 miles, and update the tire size and axle ratio in the vehicle settings so the speedometer and shift points are right.
| Brand | Yukon Gear & Axle |
| Part number | YGK079 |
| Fits | Yukon Gear & Install Kit Package Jeep JL Non-Rubicon D44 (M220) R / D30 (M186) F - 4.88 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. This kit is for the Dana 44 M220 rear. JL Sport and Sahara models with the Dana 35 M200 rear need a Dana 35 gear package. Check your VIN or window sticker before ordering.
It is listed only for the JL non-Rubicon with the Dana 30 M186 front. The Rubicon uses a Dana 44 M210 front, so it needs a different package. Send your VIN for any other Jeep and we will check.
A front Dana 30 ring and pinion, a rear Dana 44 220 mm ring and pinion, both in 4.88, and the matching Yukon master overhaul kits with bearings and the small parts needed to rebuild both differentials. Carriers are not included.
It depends on tire height, transmission and how the Jeep is driven. 4.88 is the deeper of the two ratios we stock for this axle combination; 4.56 is the milder option. Use our re-gear guide with your exact tire height to pick between them.
Yes. Update the tire size and axle ratio settings with a programmer or at a dealer so the speedometer, shift points and stability control see the correct values.
Use 75W-90 GL-5, adding friction modifier for a clutch-type limited slip. Drive gently for the first 15 to 20 miles and let it cool, avoid hard acceleration for 100 miles, wait 500 miles before towing and change the oil at 500 miles.
