Yukon Gear High Performance Replacement Gear Set For Dana 30 Short Pinion in a 4.56 Ratio

A Wrangler TJ on 33 inch tires with the factory 3.07 or 3.73 gears is a frustrating Jeep to drive: it struggles to hold fifth or overdrive on the highway, crawls poorly in 4-low and eats clutches or torque converter heat. Yukon part YG D30S-456TJ is a 4.56 ring and pinion for the standard rotation, short pinion Dana 30 under the front of non-Rubicon 1997-2006 TJs. Paired with a matching 4.56 rear, it is the ratio most TJ owners settle on for 33s. It is also the replacement when the front gears have started to howl.

What the ring and pinion does in a short pinion Dana 30

In the TJ front axle the pinion sits low, below the axle centerline, and drives a 7.20 inch ring gear fastened to the carrier with 10 bolts. The pinion is splined with 26 splines for the front yoke. A 4.56 set turns the front driveshaft 4.56 times for each turn of the front tires, and because the TJ has no axle disconnect, the front gears spin all the time, even in 2WD. Compared with a factory 3.07, a 4.56 set multiplies torque about 48 percent more; compared with 3.73 it is about 22 percent more. On a 33 inch tire at 65 mph that works out to roughly 3,020 rpm in a 1:1 gear (mph x ratio x 336 / tire diameter), before the overdrive gear brings it down, which is what restores usable highway gearing on taller tires. Yukon lists 33 inches as the largest tire it recommends for a Dana 30, which makes 4.56 about the deepest ratio this axle makes sense with.

Symptoms that call for new front gears

• A whine from the front axle at highway speed that changes when you lift off the throttle, heard even in 2WD
• The rear has already been regeared to 4.56, so the front no longer matches and the Jeep binds or hops in 4WD on pavement
• The transmission drops out of overdrive on every hill after moving to 33 inch tires
• Pinion yoke play or a leaking pinion seal that has run the front axle low on oil
• Chipped teeth or metal on the drain plug after hard wheeling in 4-low

How to confirm before you buy

Put the Jeep in 2WD and 4WD on the same stretch of road. Front gear noise is present in both because the gears always turn, but it gets louder under load in 4WD. Steering-related noise or play usually means unit bearings or ball joints instead, which our Dana 30 front axle problems guide covers. Then verify the axle: the short pinion Dana 30 has the front driveshaft entering low on the housing. Count the rear ring and pinion teeth or read the axle tag so you know exactly what ratio the rear will be. Our regear ratio guide helps decide between 4.10, 4.56 and 4.88 for your tire size and transmission.

Fitment

Yukon's fitment list for YG D30S-456TJ is the Dana 30 front, crush sleeve design, in the 1997-2006 Jeep Wrangler TJ: Sahara through 2004, SE and Sport through 2006, and the 2004-2006 Unlimited. It does not fit the TJ Rubicon, which has a Dana 44 front, or the high pinion, reverse rotation Dana 30 under the 2007-2018 JK. If you are working on a Cherokee XJ or Grand Cherokee with a low pinion Dana 30, Yukon does not list this ratio for those models, so send us your year and VIN before you order. Dana 30 ring gears mount on one of two carrier series, and 4.56 bolts to the 3.73-and-up carrier. A TJ that came with 3.07 gears needs a new carrier or a locker for that series, such as the Eaton ELocker4 for the 3.73-up Dana 30 (confirm its fitment for your Jeep). A shallower option for 31s is the Yukon Dana 30 short pinion 4.11 set, and for 35s on a light build there is the TJ Dana 30 4.88 set.

Install notes

Yukon's setup chart for the Dana 30 gives a 0.065 in. starting pinion shim, 12-15 in-lb of pinion bearing preload with new bearings, 0.006-0.010 in. backlash, 55 ft-lb on the ring gear bolts and 60 ft-lb on the bearing caps. Treat the shim figure as a starting point and confirm depth with a pattern check; our backlash and pinion depth setup guide shows how to read it. Install fresh bearings, races, shims, crush sleeve and pinion seal from the Yukon YK D30-TJ master overhaul kit, and replace the inner axle seals with an inner axle seal installer so gear oil does not wick out to the unit bearings. Fill with 75W-90 GL-5 gear oil, break the gears in with short, easy drives, and change the oil after the first 500 miles. Recalibrate the speedometer for the new ratio and tire size. For the full TJ walkthrough, including carrier swaps, see our TJ Dana 30 regear guide.

Will this 4.56 set fit my TJ Rubicon?

No. The TJ Rubicon uses a Dana 44 front. Yukon lists YG D30S-456TJ for the short pinion Dana 30 in 1997-2006 Sahara, SE, Sport and 2004-2006 Unlimited TJs.

Do I need a new carrier to run 4.56 gears?

If your Jeep came with 3.07 gears, yes. A 4.56 ring gear needs the 3.73-and-up Dana 30 carrier. Jeeps that already have 3.73 or deeper gears can keep their carrier.

Is 4.56 right for 33 inch tires on a TJ?

It is the most common choice for a TJ on 33s, especially with an automatic. Yukon recommends 33 inches as the largest tire for a Dana 30, so 4.56 is near the top of what this axle should run.

Does the rear axle have to be 4.56 too?

Yes. Front and rear ratios must match exactly or the Jeep will bind and wear tires in 4WD. Regear the rear axle to 4.56 at the same time.

What else should I buy with these gears?

A master overhaul kit with bearings, races, shims, crush sleeve and pinion seal, new inner axle seals, 75W-90 GL-5 gear oil, and a 3.73-and-up carrier or locker if you are coming from 3.07 gears.

Will my speedometer be wrong after the regear?

Yes, until it is recalibrated. Update the ratio and tire size with a programmer so speed, odometer and shift points are correct.