Yukon Gear & Install Kit For Dana 30 Front / Dana 44 Rear Jeep TJ 4.88 Ratio
Put 35 in. tires on a Wrangler TJ and the factory gearing stops making sense. Third gear feels like fifth, the 4.0 drops out of its torque on every grade, and a four-cylinder or three-speed automatic TJ barely holds speed. Yukon Gear & Axle part YGK008 is a complete 4.88 re-gear for the TJ that has a Dana 30 up front and the optional Dana 44 out back: two ring and pinion sets and a Yukon master overhaul kit for each axle under one part number.
Gear ratio and tire height work together. A TJ left factory gearing for a tire close to 29 in. tall, and every inch of tire you add stretches that ratio out. Going from 3.07 or 3.55 to 4.88 on 35s puts the engine back near the RPM it saw on stock tires at the same road speed, and it gives back low-range control off-road. On 33s, 4.88 is the stronger pick for the 2.5 four-cylinder, for automatics, and for Jeeps that tow or spend more time on trails than on the highway. Both axles in this kit are standard rotation, so the front Dana 30 gears here are the TJ short-pinion set, not the reverse-cut gears a JK front needs. Both ends have to run the same ratio, because the transfer case ties them together in 4WD. Our TJ Dana 30 4.88 regear guide walks through the tire math in detail.
First confirm the rear axle. Most TJs left the factory with a Dana 35 rear, which this kit does not fit, so check the axle tag and cover shape against our Dana 35 versus Dana 44 guide. A Rubicon has a Dana 44 at both ends and needs the TJ Rubicon 4.88 package instead. Then read your current ratio from the axle tag so you know whether you need carriers. If the real complaint is a noise, rule out the transmission and transfer case first with our driveline noise guide.
YGK008 is listed for the 1997-2006 Jeep Wrangler TJ, 4WD, with the crush-sleeve Dana 30 front and the Dana 44 rear, in a 4.88 ratio. Carriers are not in the box. Yukon's technical note says a Jeep already on 3.73 gears needs a new rear carrier, and one on 3.07 or 3.55 (listed as 3.08 and 3.54) needs new front and rear carriers, because 4.88 gears need the deeper carrier series. Our carrier break explainer covers why. That makes this the natural moment to add traction: a Dura Grip limited slip for the 30-spline Dana 44, 3.92 and up drops into the rear in place of a new open carrier. Running 33s and a six-cylinder with a manual? The 4.56 version of this kit may suit you better. Not sure what your Jeep has? Send us the year and VIN before ordering. More kits are under rebuild kits.
This is a setup job, not a bolt-in. Each axle gets pinion depth shimmed, pinion bearing preload set on the new crush sleeve or shims, carrier bearing preload and backlash set, and a marking-compound pattern checked on both drive and coast sides. Our backlash and pinion depth guide explains each step. The Dana 44 rear is tight on carrier shims, so a shim driver saves bent shims, and a clamshell bearing puller pulls setup bearings off without damage. Torque ring gear bolts with thread locker, use new pinion seals from the overhaul kits, and fill with 75W-90 GL-5, or 75W-140 in the rear if you tow, adding friction modifier for a clutch-type limited slip. Follow the ring and pinion break-in procedure, then recalibrate the speedometer for the new ratio and tire size.
| Brand | Yukon Gear & Axle |
| Part number | YGK008 |
| Fits | Yukon Gear & Install Kit For Dana 30 Front / Dana 44 Rear Jeep TJ 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 package is for a TJ that has the Dana 44 rear. Most TJs came with the Dana 35, so check the axle tag and cover before ordering, or send us your VIN.
Most likely. Yukon notes that a TJ on 3.73 gears needs a new rear carrier, and a TJ on 3.07 or 3.55 gears needs new carriers front and rear. Carriers are not included in YGK008.
Not for a four-cylinder, an automatic, or a trail-focused Jeep. On 33s with the 4.0 and a manual, 4.56 keeps highway RPM lower. On 35s, 4.88 is the usual choice.
A 4.88 ring and pinion set for the Dana 30 front and one for the Dana 44 rear, plus a Yukon master overhaul kit for each axle with bearings, races, seals, shims and setup hardware.
Use 75W-90 GL-5, or 75W-140 in the rear for towing, with friction modifier if you run a clutch-type limited slip. Drive gently with no towing for the first 500 miles, then change the oil in both axles.
No. The Rubicon has a Dana 44 front axle, so it needs a different front gear set. Use the TJ Rubicon 4.88 package instead.
