Which Axles Does My Jeep Wrangler Have? Dana 30, 35, 44, and M186 to M220 Explained, and How to Identify Them

Every Wrangler since 1987 has left the factory on solid Dana axles, and the trim level tells you which. A YJ has a Dana 30 front and a Dana 35 rear. A non-Rubicon TJ has the same pair, with a Dana 44 rear on some trims and on the long-wheelbase Unlimited; the TJ Rubicon has 44s at both ends. A JK has a Dana 30 front with a Dana 35 or Dana 44 rear depending on year and options, and 44s on the Rubicon. A JL Sport or Sahara has a Dana 30 front and Dana 35 rear, which Dana now calls M186 and M200, while the JL Rubicon and every Gladiator ride on Dana 44s called M210 front and M220 rear. To confirm, look at the axle: the model number is cast into the housing, and a build date and bill-of-material number are stamped on the tube. The number in each name is the ring gear diameter, which decides how much tire and torque the axle takes and what gears and lockers you can buy for it.

In this article

• Factory axles by Wrangler generation
• What the axle numbers mean
• How to identify the axle under your Jeep
• How to find your gear ratio
• Why the axle model matters
• What an axle swap actually means
• Frequently asked questions

Factory axles by Wrangler generation

Trim level tells most of the story. The table is built from Dana's application listings and Jeep's press kits. If you are not sure which generation you own, this guide to telling a JK from a JL sorts it out in a minute.

Where the table comes from. Jeep's 2007 JK press kit says the two-door X and Sahara "feature an enhanced Dana 30 front axle and Dana 35 rear axle," the four-door got a Dana 44 rear, and "with the optional trailer tow package, a Dana 44 rear axle is standard on all models" (Stellantis media, 2007 Wrangler); the 2018 JK fact sheet lists Sport and Sahara with a Dana 30 front and Dana 44 rear. For the TJ, Jeep's 2006 release gives the SE a "Dana 30 front axle, Dana 35 rear axle," the Unlimited a "Dana 44 heavy-duty rear axle," and both Rubicons "Dana 44 heavy-duty front and rear axles" with Tru-Lok lockers (Stellantis media, 2006 Wrangler); the 2003 Rubicon launched on Dana 44s at 4.10:1 with 31-inch LT245/75R16 tires (Stellantis media, 2003 Rubicon). Dana's catalog lists the Dana 35 rear cover for the "1987-95 Wrangler," the whole YJ run, and the Dana 30 as the YJ and TJ front (Spicer Light Vehicle Axle General Information, XGI, 2016).

For the JL and JT, Dana's parts pages supply the current names: "Dana 30 M186" front and "Dana 35 AdvanTEK M200" rear on the non-Rubicon JL, "Dana 44 AdvanTEK M210" front and "Dana 44 AdvanTEK M220" rear on the JL Rubicon and on every Gladiator (Spicer overhaul and bearing kits). Dana's JL identifier adds that a Sport or Sahara ordered with the Trac-Lok limited slip gets a Dana 44 AdvanTEK rear, and that the 3.0L diesel got Dana 44 AdvanTEK axles at both ends (Dana JK, JL, and JT product brochure, 2019). Jeep's 2018 spec sheet calls them "3rd Generation Dana axles," 3.45 standard and 4.10 on Rubicon (2018 Wrangler specifications, FCA media).

What the axle numbers mean

"Dana 30," "Dana 35," and "Dana 44" are model families; the number that matters inside each family is the ring gear diameter. Dana's catalog writes them together, so a classic Dana 30 is the "30/181" and a Dana 44 the "44/216," with the second number in millimeters. The M-series names keep only the millimeter figure: an M210 has a 210 mm ring gear. Bigger ring gear, more tooth contact, more torque capacity, and more room for a strong carrier and locker.

The classic figures come from the ring gear diameter column of Dana's Spicer general information catalog. The AdvanTEK figures come from Dana's product pages: the JL Rubicon and JT front has a "210mm ring gear" (Ultimate Dana 44 AdvanTEK front axle), and for the rear, "the gearing used in today's Dana 44 axles has a 226 mm ring gear size and has a torque capacity of 8200Nm. The new generation Dana 44 AdvanTEK gearing has a smaller 220mm ring gear size but has the same torque capacity of 8200Nm" (Spicer ring and pinion gearing for the JL). The inch figures are rounded conversions; the trailhead shorthand "the 44 is an 8.5" describes the TJ-era 216 mm axle, and the JK rear 44 is an 8.9.

How to identify the axle under your Jeep

You do not need to pull a cover. Dana's catalog spells out where the marks are: "All Spicer Carrier Type axles are identified with a manufacturing date (1) and Bill of Material number (2) stamped on the right or left hand tube on driving axles," and "the axle model number will be cast into one of the webs as shown (3), or it can be on the nose" (Spicer XGI, General Information).

1. Read the casting. Get under the Jeep with a flashlight and look at the cast iron center section. The model number is raised in the casting, on a reinforcing web or on the nose where the pinion enters; wire-brush the rust if it is faint. The casting is the most reliable identifier because it cannot change without changing the whole center section.

2. Find the stamped tube. The manufacturing date and bill-of-material number are stamped into one of the axle tubes, usually under paint and scale on an older Jeep. The bill-of-material number is the build code for that exact assembly, ratio and differential included, and it is the number a parts counter wants for a rebuild kit or ring and pinion.

3. Look at the cover. Each Dana family uses its own stamped steel cover, and the Dana 44 cover is noticeably larger because it clears a bigger ring gear. Treat it as a hint, not a verdict: covers get replaced, and the JL's AdvanTEK axles use their own covers, so a cover chart from TJ and JK axles doesn't carry over. Confirm with the casting.

4. Check the tags. Dana's catalog says "each axle contains a gear ratio tag (4), and if the axle is equipped with a limited slip differential, it will have a tag specifying the type of limited slip lubricant to be used (5)." A missing tag means nothing, since previous owners lose them, but a present one gives you the ratio and tells you whether a Trac-Lok is inside.

5. Cross-check against the trim. A 44 under a two-door JK Sport came from the tow package or a previous owner. A TJ with a 44 rear and no Rubicon badges still has a Dana 30 front; a Rubicon has 44s at both ends with Tru-Lok lockers and a 4:1 low range (Stellantis media, 2003 Rubicon). On a JL, a Dana 44 front is not automatically a Rubicon axle: Dana lists the Rubicon front as the "Dana 44 AdvanTEK Wide Track with E-Locker" and sells separate shafts for the "Open Differential" Dana 44 front on non-Rubicon JLs (Dana JK, JL, and JT product brochure).

How to find your gear ratio

The ratio tag is the easy way. When it is missing, count teeth: the axle ratio is ring gear teeth divided by pinion teeth, and Dana publishes the combinations it builds. For the Dana 44/216, the catalog lists 3.54 as 46 and 13 teeth, 3.73 as 41 and 11, 4.09 (sold as 4.10) as 45 and 11, 4.89 (sold as 4.88) as 44 and 9, and 5.38 as 43 and 8 (Spicer XGI, ring gear and pinion sets). Divide 41 by 11 to get 3.727, which is where the 3.73 comes from.

Counting means draining the gear oil, pulling the cover, marking a starting tooth, and counting all the way around; many ring gears carry the tooth counts etched on the face, which saves the counting. Plan on a new gasket or a bead of RTV and fresh oil going back together. Once you have the ratio, the gear ratio calculator on this site shows what it does with your tire size, which is the real question behind any re-gear.

Two rules from Dana's catalog apply to anyone changing gears. First, "when the vehicle is equipped with both front and rear driving axles, the gear ratios must be the same in both axles." Second, "do not change axle gear ratios on vehicles with anti-lock braking systems except in accordance with the vehicle manufacturer's instructions," because the ABS tone ring sits on the ring gear flange and its position relative to the sensor matters.

Why the axle model matters

Three practical reasons: how much the axle will take, what gears you can buy for it, and what lockers fit.

The Dana 35 question. The Dana 35 rear is the smallest ring gear Jeep has put under a Wrangler. Neither Jeep nor Dana publishes a maximum tire size for it, and this article will not invent one. What is on the record is that Jeep moved away from it: the 2007 JK two-door carried a Dana 35 only without the tow package, the four-door never had it, and by 2018 the JK Sport and Sahara listed a Dana 44 rear. On the JL, the Dana 35 AdvanTEK gives way to a Dana 44 AdvanTEK the moment a buyer checks the limited-slip box. The factory treats the 35 as the open-differential, stock-tire axle, and so should you. If the plan includes bigger tires and a locker, the rear axle is the first line item.

Gear availability. The bigger the axle, the deeper the gears. Spicer's listings run 3.21 to 5.38 for the JK Dana 44 rear, 3.45 to 5.13 for the JL Dana 30 and Dana 35 AdvanTEK, and 3.73 to 5.38 for the JL and JT Dana 44 AdvanTEK (Dana product brochure; Spicer JL gearing). Factory ratios: 3.45 standard and 4.10 on Rubicon for the JL, 4.56 with the Xtreme Recon package, and 4.88 added for Rubicon in 2022 (Stellantis media, 2022 Wrangler fact sheet); 3.73 on Gladiator Sport and Overland and 4.10 on Gladiator Rubicon (Stellantis blog, 2020 Gladiator axles). Dana's catalog also notes each model has a low-ratio and a high-ratio carrier: its example is a Dana 44 going from 3.54 to 3.73 on a ring and pinion alone, while going to 4.09 needs the high-ratio case too.

Lockers. Factory lockers come on Rubicons, always on Dana 44s: air-actuated Tru-Loks on the TJ, electric lockers on the JK, and electric Tru-Loks on the JL and JT. Other trims get the Trac-Lok limited slip at most. Aftermarket lockers exist for every Dana family, but selection and carrier strength scale with ring gear size, which is one more reason the 44 is the axle people build around. Axles also wear; the 100,000-mile parts guide on this site covers the seals, bearings, and U-joints to watch.

What an axle swap actually means

An "axle swap" means replacing the complete assembly, housing and all, with a stronger one: a Dana 44 under a Dana 35 Jeep, or a Dana 60 under a 44. This isn't a gear change or a shaft upgrade; those keep the factory housing.

There are three routes. A factory take-out, such as a JK Rubicon Dana 44 rear under a JK Sport, is the least work because the brackets, brakes, and sensors already match that generation. A junkyard axle from another vehicle usually means cutting off and re-welding spring perches or control arm brackets. A crate axle is the bolt-in option: Dana sells the Ultimate Dana 44 and Ultimate Dana 60 for the JK, JL, and JT as a "bolt-in axle assembly," built with gears and an Eaton ELocker or ARB Air Locker in ratios from 3.73 to 5.38 (Dana product brochure).

The checklist is the same for all three. Both ends must share a ratio. Brakes, ABS tone rings, and wheel speed sensors have to match the Jeep. Track width changes if the donor is wider: Jeep's 2007 press kit gives the JK a "3.5-inch wider track than predecessor," so TJ and JK axles do not interchange casually, and a JL Rubicon's wide-track axles are wider than a Sport's. The bolt pattern can change too; the Ultimate Dana 60 uses a heavy-duty 8 x 6.5 inch pattern, so wheels fit the budget. This bolt pattern guide lists the factory patterns by generation.

Most Wranglers never need a swap. The conversation starts when a Dana 35 rear meets big tires and a locker, and that is where knowing your axle before you buy parts saves the most money.

Frequently asked questions

How do I know if my Jeep has a Dana 35 or Dana 44 rear axle?

Check the cast-iron center section. Dana casts the model number into a housing web or into the nose by the pinion, so a 35 or a 44 is raised in the iron, and the Dana 44 cover is visibly larger. If rust hides the number, the bill-of-material number stamped on the axle tube identifies the exact assembly through Dana's tables.

What axles does a Jeep JL Sport have?

A JL Sport or Sahara with the open differential has a Dana 30 front, which Dana calls the M186, and a Dana 35 AdvanTEK M200 rear. The Trac-Lok limited-slip option brings a Dana 44 AdvanTEK M220 rear, and the 3.0L diesel got Dana 44 AdvanTEK axles at both ends. The Rubicon has the M210 wide-track front and M220 rear with Tru-Lok lockers.

What do M210 and M220 mean on a Jeep axle?

They are Dana's names for the third-generation Dana 44 AdvanTEK axles on the JL Rubicon and every Gladiator. The number is the ring gear diameter in millimeters: 210 mm in front, 220 mm in back. The same convention gives the JL Sport its M186 front and M200 rear.

Is the JK Dana 44 the same as the TJ Dana 44?

No. Dana's catalog lists the TJ-era axle as the Dana 44/216 with a 216 mm ring gear and every JK rear Dana 44 as the Super 44/226 with a 226 mm ring gear. The JK Rubicon front is still a 216 mm Dana 44. Gears and carriers do not interchange between the two.

Can I put 35-inch tires on a Dana 35?

Neither Jeep nor Dana publishes a tire-size limit for the Dana 35, so any number you read is an opinion. The factory record shows Jeep fitted the Dana 35 only to open-differential, stock-tire trims and went to a Dana 44 rear for tow packages, four-doors, and limited-slip options. If 35s and a locker are in the plan, budget for the rear axle.

Related reading on this site: Jeep gear ratio calculator, Jeep wheel bolt patterns and torque specs by generation, How to tell a JK from a JL, Jeep parts that fail at 100,000 miles.