Revolution Gear & Axle Dana 44 Rear Axle 5.38 Ratio Ring & Pinion Set

5.38 is a crawler ratio. It is what a Dana 44 needs when a Jeep or vintage 4x4 is running 37 to 40 in. tires, has a mild engine, or spends more time on rocks and in mud than on the interstate. The Revolution Gear and Axle D44-538 is a new 5.38 ring and pinion for the standard-rotation Dana 44, for builders putting serious tire under a TJ or XJ rear, a CJ, a classic Bronco or Blazer, or a Dodge or Ford truck axle that has to turn tall tires without cooking the clutch or transmission.

What a 5.38 gear set does in a standard Dana 44

At 5.38 the pinion turns 5.38 times for each turn of the 8.5 in. ring gear, so the engine stays in its power band even when the tire is half again taller than stock. Run the tire math before you commit: old ratio times new tire height over old tire height. A rig with 4.10 gears on 29 in. tires that moves to 38s comes out at about 5.37, a near exact match for this set. On a smaller tire, 5.38 will put the engine at high rpm on the highway, so it is a ratio for tall tires and low-speed work, not for a daily driver on 33s.

Deep ratios mean a small pinion head, which is the weak point of any Dana 44 at this ratio, and the reason 5.38 builds usually pair with a locker or spool and careful driving. Revolution specifies the family as standard rotation, 26-spline pinion, 10-bolt cover and 8620 steel with a 3.73/3.92 carrier break. This set therefore needs the 3.92-and-up carrier, such as a Dana 44 3.92-and-up open carrier or a 30-spline Dana 44 spool for 3.92 and up. If your axle has the 3.73-and-down carrier and a locker you want to keep, choose the thick-gear 5.38 set instead.

When a Dana 44 needs 5.38 gears

• 37 in. or larger tires and the engine bogging below its torque peak on climbs
• Clutch slipping or torque converter and fluid heat building on slow technical trails
• No usable top gear at highway speed on the current ratio after the tire upgrade
• Front axle already at 5.38 that the rear must match on a part-time 4x4
• Worn or chipped deep gears that whine on coast or acceleration and need replacement

Confirm before ordering

Read the regear after bigger tires guide to check 5.38 against your tire size, transmission gearing and transfer case low range. Confirm the axle is standard rotation; a high-pinion reverse-rotation front needs a reverse set. Check the current ratio on the tag, then identify the carrier with the carrier break guide so you order the right carrier or locker in the same cart.

Fitment

Revolution's chart for its standard-rotation Dana 44 sets lists the 1997-2006 Wrangler TJ and 1986-1993 Cherokee XJ rears, 1986-1992 Comanche, CJ5, CJ6, CJ7, Scrambler, Wagoneer, Grand Wagoneer, J10 and Jeepster, 1971-1977 Bronco, 1975-1978 F-150 and 1959-1977 F-250, 1969-1980 Blazer and K5, 1967-1968 C10, 1994-2001 Ram 1500, 1994-2002 Ram 2500, Ramcharger and the Dana 44 rears used in some Camaros and Corvettes. Most 5.38 builds involve axles that have already been swapped or modified, so go by the axle tag, carrier and bolt holes. This is the non-dual-drilled part number, and Revolution's family spec lists 10 x 3/8 in. ring gear bolts. Send us your year and VIN if you are unsure. See more axle parts under hard parts.

Install notes

Deep gears are the least forgiving to set up. Start from Revolution's Dana 44 figures: 0.042 in. pinion shim, 14-19 in-lb pinion preload, .006-.010 in. backlash, 60 ft-lb bearing caps and 55 ft-lb on 3/8 in. ring gear bolts, then confirm pinion depth with a marking-compound pattern. A carrier spacer or heavy shim pack is common with deep ratios, and a Dana 30-80 housing spreader keeps the carrier bearings and shims from being damaged during removal and install. Use new bearings, crush sleeve and pinion seal from a Dana 44 master overhaul kit. Break in on non-synthetic GL-5 80W-90 or 85W-140 as Revolution advises, keep the first drives short and cool, and change the oil at about 500 miles before trail use. Our break-in procedure covers heat cycles step by step.

What tire size needs 5.38 gears?

Usually 37 to 40 in. tires, depending on the transmission and how the vehicle is used. Old ratio x new tire height / old tire height gives the target; 4.10 on 29 in. tires moved to 38s works out to about 5.37.

Which carrier does a 5.38 Dana 44 set need?

The 3.92-and-up carrier. Revolution lists the break at 3.73/3.92. If your axle has the 3.73-and-down carrier, either change carriers or use the thick-gear 5.38 set.

Is a 5.38 pinion strong enough?

Deep ratios use a smaller pinion head, so a Dana 44 at 5.38 is weaker than at 4.10. It works for many trail builds with careful throttle, but very heavy rigs on 40s are often better served by a larger axle.

Is this set for a front or rear axle?

Standard rotation: rear Dana 44s and low-pinion standard-rotation fronts. High-pinion reverse-rotation fronts need a reverse set in the same ratio.

What should I buy with it?

A Dana 44 master overhaul kit, a 3.92-and-up carrier, locker or spool if you do not have one, a housing spreader if you are doing the work yourself, and break-in gear oil.