Complete 4.88 ring and pinion gear set for the Dana 30 short pinion front axle in Jeep TJ, YJ and XJ, sold as a matched pair.
Your TJ Wrangler is sitting on 35 in. tires, the stock 3.07 or 3.55 gears make it feel like it is towing a trailer everywhere, and the automatic hunts for a gear on every on-ramp. The fix is a regear, and on the front axle that means a 4.88 set for the Dana 30. This USA Standard Gear ZG D30S-488TJ is a matched 4.88 ring and pinion for the standard-rotation, short-pinion Dana 30 front axle used under the 1997-2006 Jeep Wrangler TJ and several Grand Cherokee and Cherokee models of the same era. It is a new set, cut and lapped as a pair, priced for owners who want a quiet OEM-style replacement rather than a race gear.
The pinion gear on the end of the front driveshaft drives a 7.20 in. ring gear bolted to the differential carrier. The ratio of their teeth is the axle ratio: at 4.88 the driveshaft turns 4.88 times for each turn of the tire. Larger tires act like taller gearing, so a deeper ratio restores the engine speed and torque multiplication the Jeep was designed around. On a part-time 4x4 the front and rear ratios must match exactly, so this set is always installed alongside a 4.88 rear set. Per USA Standard Gear, it fits the standard-rotation Dana Spicer 30 with the short pinion, uses a 26-spline pinion and a 10-bolt ring gear, and is cut in a 4.88 ratio.
Ring and pinion ratios on a Dana 30 also decide which carrier you need. Deep ratios like 4.88 use the 3.73-and-up carrier, so a TJ that left the factory with 3.07 or 3.55 gears needs a different carrier or locker to accept this set. An Eaton ELocker4 for the 27-spline Dana 30 in the 3.73-and-up range or a 27-spline Dana 30 limited slip solves that while the axle is apart.
Check the tag under a cover bolt or count teeth on the existing gear to confirm your current ratio, and confirm the axle is a Dana 30 and not the Dana 44 front used on the 2003-2006 TJ Rubicon. A short-pinion Dana 30 is the low-pinion design used on these models; the reverse-rotation, high-pinion Dana 30 under the JK and JL needs a different set. For gearing math by tire size, walk through our TJ Dana 30 4.88 regear guide and the broader regear after bigger tires guide.
USA Standard Gear lists this part number for these four-wheel-drive Jeep applications:
Earlier Cherokees, the YJ Wrangler and the JK/JL Wrangler are not on that list, so do not order this set for those axles. Front axles were swapped often on Jeeps of this age, so read the axle tag and ring gear bolt size before you buy, or send us your year and VIN and we will check it. Browse more gears and setup parts under hard parts.
This is a setup job, not a bolt-in. Plan on a full bearing kit such as the USA Standard ZK D30-TJ master overhaul kit, or the Yukon minor install kit only if your bearings are known to be good. Revolution Gear and Axle's published Dana 30 starting points are a 0.065 in. pinion shim, 12-15 in-lb pinion bearing preload, .006-.010 in. backlash, 55 ft-lb ring gear bolts for 3/8 in. or 75 ft-lb for 7/16 in., and 60 ft-lb bearing caps. Treat those as a baseline and confirm with a marking compound pattern. Fill with 75W-90 gear oil, keep the first 500 miles easy with no towing or long full-throttle runs, then change the oil. Reprogram the tire size and axle ratio in the PCM so the speedometer and transmission shift schedule are correct. The backlash and pinion depth setup guide covers the pattern check step by step.
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Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. The 2003-2006 TJ Rubicon uses a Dana 44 front axle. This set is for the standard-rotation, short-pinion Dana 30 front found on non-Rubicon 1997-2006 TJs and the Cherokee and Grand Cherokee years USA Standard Gear lists.
If your axle came with 3.55 or a numerically lower ratio, yes. A 4.88 set uses the 3.73-and-up carrier. Axles that already have 3.73 or 4.10 gears usually keep their carrier.
No. Neither is on the manufacturer's fitment list. The JK and JL front Dana 30 is reverse rotation and needs a different gear set.
A master install or overhaul kit with carrier and pinion bearings, a crush sleeve, pinion seal and shims, plus 75W-90 gear oil, a dial indicator and gear marking compound. The rear axle must be regeared to 4.88 at the same time.
Yes. Update the tire size and axle ratio in the PCM so the speedometer reads correctly and the automatic transmission shifts at the right points.
