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When & Why You Should Regear Your Wrangler

XT Staff
By: 

XT Staff

 / May 3 2019
When & Why You Should Regear Your Wrangler

Your Wrangler's gear ratio has an affect on how much torque and horsepower is available to you across the RPM band. Changing your gears shifts the power band forward or backwards, and can compensate for modifications like larger tires.

Shop Wrangler Gears

Depending on how you use your Jeep, you may want to consider changing out your differential's ring and pinion gears for a set more appropriate to your build. Whether you need the MPGs or the horsepower, and new set of gears can change the attitude of your rig.

Jeep Gears >

What Does a New Set of Gears Do?

One of the most common modifications done to Wranglers is installing a lift kit and a larger set of tires. Something many people forget about when they install a larger set of tires is the drivetrain was geared to provide a balance between torque and top speed. When it comes to gear ratios the higher the number the more times the driving member needs to turn. For example, the first gear on an AX-15 transmission has a gear ratio of 3.83:1 and fifth gear has a gear ratio of 0.79:1.

Gears with lower numbers are referred to as taller and higher numbers are referred to as shorter. Taller gearing provides a higher top speed and better fuel economy while shorter gearing provides more low end torque and better acceleration. Taller gearing is better for daily driving especially if you are planning on doing a lot of highway driving or are simply going to run small tires. Shorter gearing is needed for large tires and also aids in rock crawling by increasing low end torque.

How Does Gearing Work?

The gearing of your axles is set by the number of teeth on the ring and pinion gears. This determines how many times your driveshaft will have to rotate to spin the wheels once. A 4.10:1 gear ratio, for example, would mean that your driveshaft would have to spin 4.10 times to spin the wheels once.

The stock gear ratio tends to vary depending on the year and package your Jeep has. Some of the possible ratios include 3.07, 3.55, 3.73, and 4.10. Wranglers that are equipped with the Rubicon package typically come with the 4.10 gear set in their Dana 44 axles. The chart below shows the relationship between gear ratios and tire size. The numbers across the top are gear ratios, the numbers down the left side are tire sizes in inches, and the 4 digit numbers in the white boxes show RPM.

Why Should I Regear?

If you do a lot of highway driving on small to mid sized tires, it may be practical to regear to a taller setup to increase your top speed and fuel economy. If you are planning on doing a lot of off-roading or are only upgrading to a larger set of tires, you should probably install shorter gears.

When larger tires are installed, you have several things working against you: the diameter of the tire, rotational mass, rolling resistance, and the added weight of the tires. The diameter of your tires directly affects how hard your drivetrain has to work in order to move the vehicle, what you need to keep in mind is the axle is going to be turning your wheels. The axle shafts are just over an inch in diameter, and they have to turn whatever tires are on your Wrangler. This means that with a 30 inch tire you need to apply 30 times more force to the axle in order to turn the wheel. By regearing to a shorter gear, you will increase the amount of force that is being sent to the axle, this allows your Jeep to move the tires with less of a strain on the engine.

How Much it Costs to Regear Your Jeep

Replacing your Jeep's ring and pinion gears is more than simply purchasing a ring and pinion set. There are a number of bearings, seals, bolts, and the differential cover gaskets to worry about. If you're replacing the gears in both front and rear differentials, your overall cost will be understandably more. An entire gear overhaul kit will run you anywhere from $600-$1,200.

Certain differentials can only accommodate certain size ring gears. Generally, the higher numerically you go in gears, the bigger the ring gear. Should you need to upgrade the differential's carrier, this is the time to decide if you want to upgrade to lockers. No reason to do the work twice should you decide on lockers later. A new differential carrier will run about $700-$1,000.

Labor will always vary by region and shop, but you expect a ring and pinion gear installed to be approximately $500-$700 per axle. The being said, a complete regear job is several thousand dollars, done properly. 

How to Regear Your Jeep

Unless you're familiar with wrenching on your Wrangler (more than oil changes and filter swaps), we highly recommend bringing your Jeep to a professional to have ring and pinion gears installed. What follows is a simplified version of how to install gears in your Jeep. For a more detailed look, see our related installation guides.

  • Drain the differential's gear oil
  • Remove the axle shafts
  • If you're not replacing the main caps, mark them so you know which side they came from
  • Clean all new parts and remove any metal shaving within the carrier
  • Coat all new bearings and seals with fresh gear oil
  • Install the ring gear on the carrier, checking for proper shimming and backlash
  • Install the pinion gear and press on the carrier bearing, checking for proper bearing preloads
  • Reinstall the entire assembly into the differential housing

Jeep JK with the 3.6L Engine Gear Ratio & Tires Chart

Jeep JK Gear Ratio Chart for the 3.6L and the Automatic Trans. *Note* Red cells are the minimum allowable gear set. Expect sluggish performance, minimal overdrive use, and low elevation trails. Green cells are acceptable gear sets for daily driving, constant overdrive use, and slightly complex trails with moderate elevation changes. Yellow cells are performance oriented. Okay for daily driving, but more for rock crawling and extreme trails. The charts display RPMs at 70 mph in the highest gear.

Tire Size 3.21 3.73 4.10 4.56 4.88 5.13 5.38 5.86 6.17 6.50 7.17
29 2162 2512 2761 3071 3286 3455 3623 3946 4155 4377 4828
30 2090 2428 2669 2968 3177 3339 3502 3815 4016 4231 4667
31 2022 2350 2583 2873 3074 3232 3389 3692 3887 4095 4517
32 1959 2276 2502 2783 2978 3131 3283 3576 3765 3967 4376
33 1900 2207 2426 2698 2888 3036 3184 3468 3651 3847 4243
34 1844 2142 2355 2619 2803 2947 3090 3366 3544 3733 4118
35 1791 2081 2288 2544 2723 2862 3002 3270 3443 3627 4001
36 1741 2023 2224 2474 2647 2783 2918 3179 3347 3526 3889
37 1694 1969 2164 2407 2576 2708 2840 3093 3257 3431 3784
38 1650 1917 2107 2343 2508 2636 2765 3012 3171 3340 3685
39 1607 1868 2053 2283 2444 2569 2694 2934 3090 3255 3590
40 1567 1821 2002 2226 2382 2505 2627 2861 3012 3173 3500
41 1529 1777 1953 2172 2324 2443 2563 2791 2939 3096 3415
42 1493 1734 1906 2120 2269 2385 2502 2725 2869 3022 3334
43 1458 1694 1862 2071 2216 2330 2443 2661 2802 2952 3256
44 1425 1655 1820 2024 2166 2277 2388 2601 2738 2885 3182

Jeep JK Gear Ratio Chart for the 3.6L and the Manual Trans

Tire Size 3.21 3.73 4.10 4.56 4.88 5.13 5.38 5.86 6.17 6.50 7.17
29 2076 2412 2651 2949 3156 3317 3479 3789 3990 4203 4636
30 2006 2332 2563 2850 3050 3207 3363 3663 3857 4063 4482
31 1942 2256 2480 2758 2952 3103 3254 3545 3732 3932 4337
32 1881 2186 2403 2672 2860 3006 3153 3434 3616 3809 4202
33 1824 2120 2330 2591 2773 2915 3057 3330 3506 3694 4074
34 1770 2057 2261 2515 2691 28929 2967 3232 3403 3585 3954
35 1720 1998 2197 2443 2615 2749 2882 3140 3306 3483 3842
36 1672 1943 2136 2375 2542 2672 2802 3052 3214 3386 3735
37 1627 1890 2078 2311 2473 2600 2727 2970 3127 3294 3634
38 1584 1841 2023 2250 2408 2532 2655 2892 3045 3208 3538
39 1543 1793 1971 2193 2346 2467 2587 2818 2967 3125 3448
40 1505 1749 1922 2138 2288 2405 2522 2747 2893 3047 3361
41 1468 1706 1875 2086 2232 2346 2461 2680 2822 2973 3279
42 1433 1665 1831 2036 2179 2290 2402 2616 2755 2902 3201
43 1400 1627 1788 1989 2128 2238 2346 2556 2691 2835 3127
44 1369 1590 1747 1943 2080 2186 2293 2497 2630 2770 3056

Jeep JK with the 3.8L Engine Gear Ratio & Tire Chart

Jeep JK Gear Ratio Chart for the 3.8L with the Automatic Transmission

Tire Size 3.21 3.73 4.10 4.56 4.88 5.13 5.38 5.86 6.17 6.50 7.17
29 1797 2088 2295 2553 2732 2872 3012 3281 3454 3639 4014
30 1737 2018 2219 2468 2641 2776 2911 3171 3339 3517 3880
31 1681 1953 2147 2388 2556 2687 2817 3069 3231 3404 3755
32 1629 1892 2080 2313 2476 2603 2729 2973 3130 3298 3638
33 1579 1835 2017 2243 2401 2524 2647 2883 3035 3198 3527
34 1533 1781 1958 2177 2330 2450 2569 2798 2946 3104 3424
35 1489 1730 1902 2115 2264 2380 2495 2718 2862 3015 3326
36 1448 1682 1849 2056 2201 2313 2426 2643 2782 2931 3233
37 1408 1637 1799 2001 2141 2251 2361 2571 2707 2852 3146
38 1371 1594 1752 1948 2085 2192 2298 2504 2636 2777 3063
39 1336 1553 1707 1898 2031 2135 2240 2439 2568 2706 2985
40 1303 1514 1664 1851 1981 2082 2184 2378 2504 2638 2910
41 1271 1477 1623 1806 1932 2031 2130 2320 2443 2574 2839
42 1241 1442 1585 1763 1886 1983 2080 2265 2385 2512 2771
43 1212 1408 1548 1722 1842 1937 2031 2212 2329 2454 2707
44 1184 1376 1513 1682 1801 1893 1985 2162 2277 2398 2645
Tire Size 3.21 3.73 4.10 4.56 4.88 5.13 5.38 5.86 6.17 6.50 7.17
29 2188 2542 2795 3108 3326 3497 3667 3994 4206 4431 4887
30 2115 2458 2701 3005 3215 3380 3545 3861 4065 4283 4724
31 2047 2378 2614 2908 3112 3271 3431 3737 3934 4145 4572
32 1983 2304 2533 2817 3014 3169 3323 3620 3811 4015 4429
33 1923 2234 2456 2731 2923 3073 3223 3510 3696 3893 4295
34 1866 2169 2384 2651 2837 2982 3128 3407 3587 3779 4169
35 1813 2107 2316 2575 2756 2897 3038 3310 3485 3671 4049
36 1763 2048 2251 2504 2680 2817 2954 3218 3388 3569 3937
37 1715 1993 2190 2436 2607 2741 2874 3131 3296 3473 3831
38 1670 1940 2133 2372 2538 2669 2799 3048 3210 3381 3730
39 1627 1891 2078 2311 2473 2600 2727 2970 3127 3294 3634
40 1586 1843 2026 2253 2412 2535 2659 2896 3049 3212 3543
41 1548 1798 1977 2198 2353 2473 2594 2825 2975 3134 3457
42 1511 1755 1930 2146 2297 2414 2532 2758 2904 3059 3375
43 1476 1715 1885 2096 2243 2358 2473 2694 2836 2988 3296
44 1442 1676 1842 2049 2192 2305 2417 2633 2772 2920 3221

TJ Wrangler Speedometer Gear Tooth Chart

Electric Driven Speedometer Gear Chart for 1993-2006 Wranglers - Short Shaft

Gear Ratios 44" Tire 42" Tire 40" Tire 38" Tire 36" Tire 35" Tire 34" Tire 33" Tire 32" Tire 31" Tire 30" Tire 29" Tire 28" Tire 27" Tire
5.38 34 36 38 40 42 43 - - - - - - - -
5.13 32 34 36 38 40 41 42 43 - - - - - -
4.88 30 32 34 36 38 39 40 41 43 - - - - -
4.56 28 30 32 34 36 37 38 39 40 42 43 - - -
4.10 - 26 28 30 32 33 34 35 36 37 38 39 40 41
3.73 - - - 26 28 29 30 31 32 33 34 35 36 37
3.55 - - - - 27 28 29 30 31 32 33 34 35 36
3.07 - - - - - - - - 26 27 28 29 30 31

Jeep Stock Gear Ratio Chart and Differential Chart

Non-Rubicon Front Rear Option
YJ Dana 30 (27 Spline) Dana 35 (27 Spline) Dana 44 (30 Spline)
TJ
JK Dana 44 (30 Spline) -
*Early 2007 JKs may have the Dana 35, mid-run change
Rubicon Front Rear Option
TJ Dana 44 (30 Spline) -
JK
Stock Gearing YJ TJ JK
2.5L I4 Auto 3.73 -
2.5L I4 Manual 4.10
4.0L/4.2L I6 Auto 3.55
4.0L/4.2L I6 Manual 3.07
3.6L V6 Auto - 3.21 (3.73/4.10)
3.6L V6 Manual -
Stock gearing in Rubicons is 4.10 regardless of trans/engine/gen
Fitment includes: JL, JK, TJ, YJ, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, Laredo, Sport, Islander, S, Sahara, Renegade, SE, X, Rubicon, Unlimited, Sport-S