4Runner Re-Gear for 35s: What Ratio, What It Costs
If you have put 35s on a 5th gen 4Runner, the ratio you want is 4.88. The truck left the factory with 3.727 gears turning a tire around 31.6 inches tall. A 35 drops the effective ratio to roughly 3.37 — about a 10 percent loss — and that math happens before you bolt on a steel bumper, sliders, a rear bumper with a tire carrier and a loaded rack. 4.88 lands the effective ratio near 4.41, which is where a loaded 35-inch 4Runner actually wants to live.
4.56 is the right call only for a light 35-inch build that spends most of its miles on pavement. 4.10 and 4.30 get cited constantly because they restore the factory feel, and restoring factory feel is the wrong target: the 4.0-liter V6 and its five-speed automatic were already geared tall for a 4,750-pound truck, and your truck no longer weighs that. Plan on $1,600 to $2,600 for both differentials done properly, and read the carrier break and factory-locker sections before you order anything.
35s on a 5th gen 4Runner: 4.88 front and rear. 33s: 4.56. 37s: 5.29. Both differentials, same ratio, same time — the 4Runner has no center differential, so mismatched ratios destroy the transfer case. And re-gearing does not fix your speedometer; that is a separate job you owe the truck either way.
The math, and why it argues for more gear than you expect
Gear ratio and tire diameter multiply. Divide the new tire into the old one, multiply by the stock ratio, and you get what the drivetrain is now effectively working with. On a 5th gen 4Runner running the factory 265/70R17 — call it 31.6 inches — the numbers land like this.
| Ratio on 35″ | Effective ratio | vs. stock feel | Verdict |
|---|---|---|---|
| 3.727 (stock, untouched) | 3.37 | 10% taller | Hunting for gears, hot transmission, dead off idle |
| 4.10 | 3.70 | Even | Money spent to get back to a compromise |
| 4.30 | 3.88 | 4% deeper | Not enough for a built 35″ truck |
| 4.56 | 4.12 | 10% deeper | Light, mostly-pavement 35″ builds |
| 4.88 | 4.41 | 18% deeper | The answer for most 35″ builds |
| 5.29 | 4.78 | 28% deeper | 37s, or 35s with heavy armor and a supercharger |
The row people argue about is 4.56 versus 4.88, and the argument usually skips weight. A 4Runner that has earned its 35s typically carries a steel front bumper, sliders, a rear bumper with a swing-out, drawers and a roof rack. That is commonly 400 to 800 pounds over stock, permanently, plus the rotating mass of four tires that each weigh 20 to 30 pounds more than what they replaced. Rotating mass costs you more than static weight does, because the drivetrain has to accelerate it and the brakes have to stop it. Gear ratio is the only lever that addresses both.
The one real cost of 4.88 is cruising RPM. Expect roughly 400 to 500 more RPM at 75 mph than 4.56 delivers. On the 1GR-FE that is not a durability concern — it is a noise and a fuel economy concern, and most owners report the fuel economy difference between the two ratios is inside the noise band anyway, because the taller ratio simply forces more downshifts. If you tow at highway speed regularly and never leave pavement, 4.56 is defensible. Otherwise the deeper ratio is the one you will be glad you bought.
Which axles you are working with
The 5th gen 4Runner (2010–2024) uses an 8-inch clamshell independent front differential and an 8.2-inch solid rear axle. The clamshell design is the reason front gear work costs more labor than rear: the housing splits, the CV axles come out, and there is no bolt-off third member to hand across the counter. The rear on TRD Off-Road and TRD Pro trims carries the factory electronic locker, which changes which gear package you order.
Fourth gen trucks (2003–2009) share the same basic clamshell front and an 8-inch rear, so most of this page transfers, with the caveat that the 4.7-liter V8 trucks have a different torque curve and tolerate a shade less gear. The 6th gen gets its own section at the bottom, because the answer there is genuinely different.
The carrier break, and the question to ask your shop
A ring gear for a deep ratio is physically thicker than one for a shallow ratio, and at some point it no longer fits the carrier it is bolting to. On the 4Runner that dividing line sits between the 3.73-and-numerically-lower group and the 3.91-and-numerically-higher group. Your truck came with 3.727. Going to 4.56 or 4.88 crosses the break.
The good news is that reputable manufacturers — Nitro, Revolution, Yukon — sell thick-cut gears specifically machined to bolt to the 3.73-and-down carrier already in your truck. That turns a potential extra several hundred dollars into a non-issue. If a quote line-items a new carrier, ask directly whether a thick gear set would eliminate it. Sometimes the answer is that you are installing a locker anyway and the carrier is coming out regardless, which is fine. Sometimes the answer is that nobody checked.
The parallel trap is the factory rear e-locker. Gear packages are sold in "with factory locker" and "without factory locker" versions and they are not interchangeable. Order the wrong one and the parts sit in a box while your truck sits on a lift. Know your trim before you click buy.
What it costs in 2026
| Line item | Typical range | Notes |
|---|---|---|
| Ring & pinion sets, front + rear | $450–$700 | Roughly $200–$350 per end |
| Master install kits, both ends | $200–$400 | Timken or Koyo bearings, crush sleeves, shims, seals |
| Labor, both differentials | $900–$1,500 | Clamshell front is the expensive half |
| Gear oil, RTV, break-in fluid change | $60–$120 | You are buying it twice — see break-in below |
| Speedometer calibration | $200–$450 | Separate problem, separate fix |
All-in, most people land between $1,600 and $2,600. Quotes meaningfully under about $1,200 for both ends deserve a question about what is being skipped — reused bearings and a rushed pattern are the usual answers, and both show up later as a whine you cannot unhear at 45 mph. Gear setup is one of the few jobs where the labor is worth more than the parts, and where a cheap install can cost you the parts twice.
Two ways to bring that number down honestly. Bundle the work: if a front e-locker, a rear locker or an axle seal replacement is anywhere on your list, doing it in the same teardown saves several hundred dollars in duplicated labor. And do the removal yourself if the shop allows it — some will discount a job that arrives with the front skids and CV axles already out.
Setup is the whole job
Differential setup means establishing pinion depth, pinion bearing preload, carrier bearing preload and backlash, then confirming all four by reading the contact pattern in marking compound. Every one of those is measured, adjusted with shims, and re-measured. There is no torque spec that substitutes for reading the pattern, and there is no way to check your work later except by listening for a whine that means the gears are already wearing wrong.
This is not a first-time driveway job, and saying otherwise does readers no favors. If you have set up gears before and own a dial indicator, an inch-pound beam torque wrench, a press and a shim kit, you know that already. If you have not, the shop labor is buying you the one thing you cannot buy in a box: someone who has read a few hundred patterns and knows what a slightly-too-deep pinion looks like before it becomes a noise. Ask a prospective shop how many Toyota clamshell fronts they do a month. The number tells you more than the hourly rate does.
Break-in, and the fluid change nobody does
New gears shed metal while the tooth surfaces work-harden against each other. That debris circulates in the oil, and leaving it there is how a good setup turns into a noisy one. The break-in that gear manufacturers actually specify looks like this:
- First 500 miles: vary your speed, stay off the throttle, and do not tow. Heat cycling matters more than mileage. Pull over and let the differentials cool every 15 to 20 miles for the first hundred.
- Change both differential fluids at 500 miles. This is the step that gets skipped and the one that protects the install. Expect the drained oil to look metallic; that is the point of doing it.
- Keep it gentle for another 500 miles, then drive normally.
- Change fluid again around 3,000 miles, then settle into a normal interval — every 30,000 miles, or after any water crossing deep enough to reach the axle breather.
Use a quality 75W-90 GL-5 gear oil in both ends, and add friction modifier only if the rear carries a limited-slip — the factory e-locker does not need it. If you are doing any of this yourself, a tube of gear marking compound costs almost nothing and lets you photograph your own contact pattern before the cover goes back on, which is worth having if a whine shows up later and the shop wants to discuss it.
The speedometer, which re-gearing does not fix
This trips up a lot of people, so it is worth stating plainly: on a 4Runner the speedometer takes its signal from the wheel speed sensors, not from the differential. Changing the ring and pinion changes nothing about what the cluster reads. The 35-inch tire is what put the speedometer out, and the 35-inch tire is still there.
The error runs roughly 10 percent low: an indicated 70 is about 77 actual. The odometer under-counts by the same margin, which quietly stretches every oil change and every warranty mile. Fix it with a plug-in speedometer calibration device or with an ECU flash that includes tire size, and do it whether or not you ever re-gear. It also matters for the systems reading those same sensors — A-TRAC and VSC make their decisions on wheel speed, and feeding them a consistent 10 percent error is not something you want happening on a wet off-camber section.
If you are on 33s, or on a 6th gen
For 33s on a 5th gen, 4.56 is the ratio and the honest add is that you may not need to do this at all. A stock-height-to-mildly-lifted truck on 33s with no armor is drivable on factory gears; annoying in the mountains, fine everywhere else. If the truck is loaded or you tow, 4.56 transforms it. If it is a mall-and-forest-road build, put the money toward tires and recovery gear first and re-gear when the armor goes on.
The 6th gen (2025+) is a different conversation and the answer today is mostly wait. The TNGA-F platform, the 8-speed automatic and the turbocharged 2.4 — especially the i-FORCE MAX hybrid, with 465 lb-ft available essentially off idle — change what a tire upgrade costs you in a way the naturally aspirated 4.0 never allowed. Owners running 35s on 6th gens broadly report the truck copes without a re-gear far better than a 5th gen does. Aftermarket gear availability for the platform is also still thin. Confirm your own truck's factory axle ratio from the door jamb or window sticker before you calculate anything, drive it loaded on the tires you actually run, and revisit this once you have real data and the parts catalogs have filled in.
The honest verdict
A 5th gen 4Runner on 35s with factory 3.727 gears is a truck working against itself — hunting between gears on grades, running the transmission hotter than it should, and giving up the low-end response that made it good on a trail in the first place. 4.88 front and rear is the fix, it costs what it costs, and there is no cheaper version of it that ends well.
What you can control is sequencing. Re-gearing is the mod that makes every other mod work, so it belongs immediately after the tires, not three years later once you have already lived with the compromise. If the budget only stretches to one differential this year, the answer is not one differential — it is waiting until it covers both. Run the numbers for your exact tire and ratio on the gear ratio calculator, get two quotes from shops that do Toyota clamshells regularly, and do it once.