Most Raptor owners running 37s do not need to regear, and you should know that before you spend two grand. The factory 4.10 gears plus a wide-ratio 10-speed already give the EcoBoost more than enough to pull 37s on the street. Regear when you've added real weight, when you tow, or when you've gone bigger than 37s — not reflexively because you changed tires.
The Raptor ships with 4.10 gears front and rear from the factory, paired with 35-inch tires (Gen 1/2) or 35s with a factory 37 option (Gen 3). Going from 35s to 37s is only about a 5–6 percent increase in tire diameter, which drops your effective gearing from 4.10 to roughly an effective 3.86. On a heavy, turbocharged truck that already makes its torque low in the rev range, that's a change you can feel but rarely a change you need to fix. This is where the Raptor differs from a naturally aspirated Wrangler on 37s: the EcoBoost's torque and the 10-speed's ratio spread absorb the larger tire far better than a six-speed Jeep does.
So the honest verdict is a decision tree, not a default. If your Raptor is mostly stock weight, runs 37s, and lives on pavement and fire roads, leave the gears alone — you'll spend $2,000 to recover a few percent you won't notice in normal driving. If you've hung steel bumpers, a winch, sliders, skids, and a bed rack on it, or you tow a trailer, or you've gone past 37s, then regearing back to 4.56 or 4.70 restores the launch feel, transmission shift behavior, and towing manners the factory engineered around 35s.
This is a full differential job on both axles — the Raptor uses a 9.75-inch rear and a matched independent front, and you must regear them as a pair so the front and rear ratios match. The rear is a conventional ring-and-pinion setup; the front is more involved because of the IFS carrier. Quality gear sets come from Nitro Gear & Axle, Yukon, Revolution, and Motive, typically $300–360 per axle. Each axle also needs a master install kit (bearings, shims, crush sleeve or solid spacer, seals, marking compound) — Yukon master kits run about $100–130 per axle.
Common ratio choices over the factory 4.10:
Match the locker and any aftermarket carrier to the new ring gear's carrier break if applicable, and confirm your generation's axle specifics before ordering — gear sets are axle-specific.
Regearing is a precision setup job, not a bolt-on, and it is the one item on most Raptor build lists worth paying a competent shop to do. The setup tolerances are tight and a mistake here means a whining, short-lived differential. In outline:
1. Drain the diff, remove the cover (rear) or carrier, and document the factory backlash and pinion depth before teardown.
2. Press off the old pinion and carrier bearings; press on new ones.
3. Set pinion depth with shims, install the new pinion with correct bearing preload (crush sleeve or solid spacer), and set backlash with the carrier shims.
4. Read the gear contact pattern with marking compound and adjust pinion depth and backlash until the pattern is centered on drive and coast faces.
5. Repeat the full process on the second axle so both ratios match exactly.
6. Reassemble, fill with the correct gear oil (and friction modifier if the diff is limited-slip), and follow a break-in: gentle driving with a heat cycle and cooldown for the first few hundred miles, then a fluid change.
If you have not set up a differential before, this is not the job to learn on. The cost of a redo — pressed bearings, a fresh master kit, possibly a damaged gear set — erases any savings from doing it yourself.
Both axles must match. Running 4.56 in the rear and 4.10 in the front will bind the transfer case and destroy driveline components — this is the single most important rule of a 4WD regear.
Don't over-gear. The instinct after adding 37s is to jump to 4.88, but on the 10-speed Gen 2/3 trucks that often leaves the truck buzzing at highway speed for no real-world gain. For 37s, 4.56 is the sweet spot for most builds; save 4.70/4.88 for genuinely heavy or oversized setups.
Budget for break-in and a follow-up fluid change. New gears shed metal as they seat, and skipping the early oil change is how a correctly set-up diff still fails early.
Parts run about $700–1,000 for two gear sets plus two master kits. Professional setup of both axles typically adds $900–1,400 in labor depending on the shop, putting a done-right regear in the $1,600–3,000 range all in. DIY drops the labor but demands the specialty tools (dial indicator, bearing press, case spreader) and the experience to read a pattern.
Before committing, do the math on your actual use. If you're on 37s and the truck still feels strong loaded and at speed, your money is better spent elsewhere — read the [tire fitment guide](/db/?v=raptor) to confirm you've got the clearance dialed first, and the [axle and CV service guide](/db/?v=raptor) to make sure the diffs you have are healthy before you open them up.
| Part | Vendor | Est. price |
|---|---|---|
| Nitro Gear & Axle ring-and-pinion set (rear 9.75") | Nitro Gear & Axle | ~$320 |
| Nitro Gear & Axle front ring-and-pinion set | Nitro Gear & Axle | ~$360 |
| Yukon Gear & Axle master install kits (front + rear) | Yukon Gear & Axle | ~$220 |
| Revolution Gear & Axle ring-and-pinion sets (per axle) | Revolution Gear & Axle | ~$330 |
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.