No announcement yet.

Tires & Gears

  • Filter
  • Time
  • Show
Clear All
new posts

  • Tires & Gears

    Is there any sort of chart or table that shows what gears are best recommended for which size tires? I have a stock JL Rubicon, so it has the Dana 44’s, 4.10s, and 33 inch tires. How do I know what tire size I can go up to without having to regear and just say I wanted to go up to 40’s, what gears are best for that. Knowledgeable responses only please. I’m still new and learning, but knowing your buddy’s nephew ran 40s with 4.10 gears for years with no problems doesn’t help me. Thanks.

  • #2
    37” KM3 tires on my 2019 JLUR have been pretty good with the stock 4:10 gears.


    • #3
      James NVRDUN Foster

      83 CJ-7, 4.5 Rubicon Express Suspension, 35" BFG Krawlers, Rancho 9000's, 258 In-line six, T-18, Dana 20 Transfer Case w/Terra Low, 4:56 Gears, SunRay Ford 9 Inch Rear w/Detroit Locker, Dana 30 w/LockRight, Plates \"NVRDUN\" and A Proud Member of The Lone Star Jeep Club


      • #4
        You can calculate it using this formula

        Gears needed to keep the same ratio of power to tire diameter = old gear x new tire diameter /old tire diameter

        So in your case of 33s and 4.10 gears and going to 40s...

        New gears = 4.10 x 40 / 33 = 4.96 gears so 4.88 would lose a bit of power, and 5.13 would have a bit more torque.

        More torque is better crawling and acceleration but revs higher on the highway hurting gas mileage a bit.