You bolted on the lift and the bigger tires. The truck looks right. But now the transmission hunts on every grade, the engine lugs at highway speed, and you are wondering whether the stock gears are still doing their job. This guide answers the regear question the way GX owners actually experience it: what regearing changes, what your stock ratios are, what it costs, and when you can skip it.

What regearing actually does

Your axle ratio is the number of driveshaft turns for each turn of the wheels. A 3.73 ratio means the driveshaft spins 3.73 times to turn the wheels once. A numerically higher ratio, like 4.56, multiplies engine torque more before it reaches the tires. That is the whole job: restoring the leverage that bigger tires take away.

Bigger tires are a taller final gear in disguise. They increase the distance the truck travels per wheel revolution, so the engine turns slower for a given road speed and works harder to accelerate the heavier tire. You feel it as lazy throttle response, a transmission that downshifts on mild hills, and the torque converter unlocking when it used to stay locked. A regear swaps the ring and pinion gears in the differentials to bring engine speed back up into the range where the truck was designed to run.

The ratio is just tooth math. Ring gear teeth divided by pinion teeth. On a stock GX470 that is 41 divided by 11, which equals 3.727 to 1.

Your stock axle ratios

• GX470 (2003 to 2009): 3.727 to 1 (41 ring teeth, 11 pinion teeth), paired with the 5-speed automatic ^[1].
• GX460 (2010 to 2023): 3.909 to 1 (43 ring teeth, 11 pinion teeth), paired with the 6-speed automatic ^[2].
• GX550 (2024 and newer): not verified. Factory gearing for the GX550 is not confirmed from any source on file, so this guide makes no claim about it.

The GX460 starts with a meaningful advantage. That 3.909 stock ratio plus the 6-speed’s extra overdrive gear is why GX460 owners tolerate 33s even better than GX470 owners do. One GX460 owner measured roughly 1,900 rpm at 75 mph in 6th gear on stock tires, and noted the V8 masks a lot of the gearing loss that a V6 truck would feel ^[3].

Both trucks are full-time 4WD. That detail matters for cost: the front and rear axle ratios must match, so a regear means doing both diffs ^[4].

The short answer: 33s no, 35s probably yes

This is the owner consensus across GX470, GX460, 4Runner, and Tacoma threads, and the math below backs it up.

On 33s, you do not need to regear. Owners running 285/70R17s (a true 32.7 inch tire) on stock gears report no real complaints. One long-running 4Runner thread put it plainly: there are about a million owners on 33s with factory gearing and no complaints whatsoever ^[5]. An IH8MUD regular was blunter: for 33s and light wheeling, a regear is a waste of money ^[6]. The GX460 crowd is even more relaxed, with owners saying they see no need until 34 inch tires or heavy 33s ^[3].

On 35s, most owners want 4.56 gears. The gearing loss crosses the line where the truck feels tired, especially towing or at altitude. The standard recommendation for 35s on these trucks is 4.56 ^[7]. Owners who run heavy armor, bumpers, and a winch on 35s sometimes step to 4.88 ^[8].

The chart below shows why. It plots the effective final drive ratio, which is what your engine actually feels, for each tire size. Anything below your stock reference line is gearing you have lost.

Read it this way. A GX470 on 35s with stock gears feels like a 3.25 axle, well below its stock 3.727. Regearing to 4.56 brings the effective ratio to 3.98, slightly lower than stock feel, which is exactly what most owners want on 35s. But 4.56 on 33s gives 4.27, noticeably lower than stock, which is why one experienced owner warned that 4.56 is a little too much gear for 33s on the highway ^[7]. If you know you will stay on 33s forever, keep your money. If 35s are in your future, gear for the 35s.

What a regear costs at a shop

There is no way around the price. Both diffs need new ring and pinion sets, master install kits with bearings and seals, and several hours of skilled setup labor each. Owner-reported numbers cluster in a clear range:

• Mail-in third members: around $1,500 for both diffs, no lockers, when you pull the carriers yourself and ship them to a gear shop ^[9].
• Full shop job, drive in and drive out: around $2,400 to $2,500 for both axles with parts and labor, based on owner quotes from Toyota-specialist gear shops ^{[10] [11]}.

Those are owner-reported figures, not quotes, and your region and shop will move the number. Add a locker while the diff is apart and the parts cost goes up, but the setup labor is mostly already paid for, which is why so many owners do lockers and gears in one visit. Budget a 500-mile break-in of gentle driving with cool-down cycles after new gears, per the gear makers’ standard guidance.

Why gear setup is not a shadetree job

Swapping a ring and pinion is not a bolt-on. The pinion depth and the backlash between the gears are set with shims in increments the factory manual measures in hundredths of a millimeter. The 2005 GX470 manual specifies drive pinion to ring gear backlash of 0.11 to 0.18 mm (0.0043 to 0.0071 in) ^[12]. The contact pattern between the teeth is read with marking compound and adjusted, checked, and adjusted again until the pattern sits centered on the tooth. Get it wrong and the gears howl, overheat, or fail early. Bearings are pressed on and off, which needs a real press, and the crush sleeve or solid spacer that sets pinion bearing preload is a one-shot part.

The shadetree alternative that actually works: do the removal and reinstallation yourself, and let a gear shop do the setup. Pulling the rear third member and the front clamshell diff, then shipping or driving them to a specialist, cuts the labor bill roughly in half while keeping the precision work in experienced hands. That is exactly what the mail-in programs from shops like East Coast Gear Supply are built for ^[9].

Speedometer and odometer after bigger tires

Bigger tires make your dash lie. The truck computes speed from wheel revolutions, so a taller tire covers more ground per revolution than the computer expects. Your speedometer reads low, your odometer under-counts miles, and your MPG math comes out wrong unless you correct for it.

On 285/70R17s, the most common 33, the dash reads 65 mph while you are actually doing close to 70. On true 35s it is 74. Your odometer under-reports by the same percentage, which quietly makes your fuel economy look worse than it is and puts fewer miles on the odometer than the truck actually travels. Worth knowing at resale time.

Fixes, in order of effort:

• Do the math in your head. Free, and what most owners actually do. Multiply dash speed by 1.07 on 285/70R17s.
• SpeedoHealer. An inline signal corrector that GX470 owners have wired into the speed signal going to the combination meter, correcting the speedometer, odometer, and trip computer together. It requires cutting one cluster wire, so it is a committed install ^[13].
• Rough Country 90043 calibrator. A $199.95 plug-in programmer that corrects the speedometer through the OBD port and also updates shift points and stability control calibration. It is listed for the 2016 to 2023 Tacoma 4WD only. GX470/GX460 fitment is not confirmed, so verify before buying ^[14].

MPG and transmission behavior

Expect to lose fuel economy with bigger tires no matter what. The tires are heavier, they have more rolling resistance, and they push more air. Regearing does not magically restore stock MPG. What it restores is drivability: the transmission holds gears instead of hunting, the converter stays locked, and the engine stops lugging below its happy rpm on grades. Owners describe the difference as the truck feeling stock again rather than the truck sipping fuel again.

Where you will feel the gearing loss most: towing, altitude, and headwinds. A GX470 owner towing a 4,000 lb camper found 5th gear at 65 mph sat around 1,800 rpm, too low to pull anything but flat ground, while 4th gear at 2,700 rpm pulled great but drank fuel. His math said 4.56 gears with 33s would put the sweet spot right at 2,200 to 2,300 rpm ^[15]. If you tow with big tires, that is the use case where a regear earns its keep fastest.

A cheaper first step for shift behavior: drive in S mode and lock out the top overdrive gear on grades, or use tow/haul mode. It costs nothing and fixes half the hunting complaints.

The honest alternative: live with stock gears

Most GX owners on 33s never regear, and most are happy. The 2UZ and 1UR V8s have enough low-end torque to mask the gearing loss in daily driving, and the money stays in your pocket. Even on 35s, owners with a light foot report it is tolerable around town. The regear is worth it when the truck’s actual job demands it: towing, heavy armor, high altitude, or 35s as a daily reality rather than a weekend look.

If you are on the fence, run the tires for a few months first. You will know by the third long grade whether you want the gears.

Parts and tools

A regear buys parts in pairs. Everything below is needed front and rear.

Part	Notes
Ring and pinion set, 4.56 ratio	The standard pick for 35s on GX470/GX460. Consider 4.88 for heavy armor and bumpers
Ring and pinion set, 4.88 ratio	Optional step up for loaded expedition builds on 35s
Master install kit, front	Bearings, seals, shims, crush sleeve or solid spacer, marking compound
Master install kit, rear	Bearings, seals, shims, crush sleeve or solid spacer, marking compound
Gear oil, 75W-90 GL-5	For the front and rear fills after setup; buy extra, both diffs get fresh oil
Dial indicator with magnetic base	For the shop doing setup; verifies the 0.11 to 0.18 mm backlash spec [12]
Shop press, 12 ton or larger	For the shop; bearings are pressed on and off

Torque note for anyone reassembling a carrier: the factory manual specifies the differential case to ring gear bolts at 71 ft·lbf (97 N·m) on the GX470 ^[16].

FAQ

Do I need to regear my GX470 for 33s? No. The owner consensus is clear: 33s on the stock 3.727 gears drive fine. Save the money for tires and maintenance.

Do I need to regear my GX460 for 33s? No. The GX460’s 3.909 stock gears and 6-speed automatic handle 33s even more comfortably than the GX470 does.

What gears for 35s on a GX470 or GX460? 4.56 is the standard recommendation. It brings the effective ratio back to slightly lower than stock feel, which suits the extra tire weight. Heavy expedition builds on 35s sometimes run 4.88.

Can I regear just the rear axle? Not on a full-time 4WD GX. The front and rear ratios must match or the transfer case and center differential will fight themselves. Budget for both diffs.

Will a regear fix my speedometer? No. Gears change engine rpm for a given speed, but the speedometer error comes from tire diameter. Correct the speed signal separately with a calibrator, or just do the mental math.

How much does it cost to regear a GX? Owner-reported figures run about $1,500 for a mail-in job where you pull the diffs yourself, and $2,400 to $2,500 for a full drive-in, drive-out shop job on both axles. Get a real quote from a gear shop near you.

Will regearing improve my MPG? Some owners see a small improvement in mixed driving because the engine stops lugging, but do not buy gears expecting them to pay for themselves in fuel. Buy them for drivability.

Sources

• IH8MUD, GX470 axle gears and lockers upgrade thread: https://forum.ih8mud.com/threads/axle-gears-lockers-gx470-upgrade-thread.1051492/page-6
• IH8MUD, GX460 and GXOR discussion thread: https://forum.ih8mud.com/threads/gx460-gxor-b-s-thread.1315456/page-21
• 4Runners.com, regearing for 33s thread: https://www.4runners.com/threads/regearing-for-33s.17741/
• 4Runners.com, regear group buy with Premier West Gear: https://www.4runners.com/threads/regear-group-buy-open-to-all-makes-models.30345/
• TacomaWorld, 35 inch tires regear thread: https://www.tacomaworld.com/threads/35-in-tires-should-i-re-gear.617684/
• TacomaWorld, do I need to regear with 33s thread: https://www.tacomaworld.com/threads/do-i-need-to-re-gear-with-33s.803620/
• IH8MUD, regearing questions thread: https://forum.ih8mud.com/threads/regearing-questions.235493/
• Tundras.com, to regear or not to regear thread: https://www.tundras.com/threads/to-regear-or-no-regear-that-is-the-question.83320/
• WranglerTJForum, regear cost thread: https://wranglertjforum.com/threads/2400-and-the-alabama-high-step-for-a-re-gear.64436/
• IH8MUD, speedometer and odometer recalibration thread: https://forum.ih8mud.com/threads/speedo-odometer-recalibration-for-larger-tires.1107043/
• Rough Country, speedometer calibrator 90043: https://www.roughcountry.com/product/speedometer-calibrator-90043
• Tinkerer’s Adventure, “The Truth Inside Differential Lockers: It’s Not Simply Air vs Electric!” (YouTube): https://www.youtube.com/watch?v=A8O6YWIuS-U
• Tinkerer’s Adventure, “Everything WRONG with EATON E-Lockers: Still Better Than ARB?” (YouTube): https://www.youtube.com/watch?v=TBWhDYoPnmE
• Chasing Dust, “Regearing Explained” (YouTube): https://www.youtube.com/watch?v=FBigSE-U7fk
• Nitro Gear & Axle, “Why Re-Gear Your Modified Car, Truck, or SUV?” (YouTube): https://www.youtube.com/watch?v=TkfIya_kOQw
• The Truck Garage, what PSI should you run in upsized tires: https://thetruckgarage.com/what-psi-should-you-run-in-upsized-tires-gx470-gx460-gx550/

Footnotes

^[1] GX470 stock ratio of 3.727 (41:11) confirmed in the IH8MUD GX470 axle, gears, and lockers upgrade thread.

^[2] GX460 stock ratio of 3.909 confirmed by GX460 owners in the IH8MUD GX460 thread and the GX470 upgrade thread.

^[3] GX460 owner report: approximately 1,900 rpm at 75 mph in 6th gear on stock tires, with no perceived need to regear below 34 inch tires, from the IH8MUD GX460 thread.

^[4] Full-time 4WD requires matching front and rear ratios; noted in the IH8MUD GX470 upgrade thread discussion of GX460 diff swaps.

^[5] 4Runners.com regearing-for-33s thread: owners report no complaints running 33s on factory gearing.

^[6] IH8MUD regearing questions thread: owner advice against regearing for 33s with light-duty use.

^[7] TacomaWorld 35 inch tire regear thread and IH8MUD: 4.56 recommended for 35s; 4.56 considered more gear than needed for 33s on the highway.

^[8] 4Runners.com regear thread: 4.88 recommended for 34s and 35s with bumpers and heavy carried weight.

^[9] TacomaWorld 35s regear thread: owner-reported East Coast Gear Supply mail-in price of about $1,500 for a regear with no lockers, both diffs.

^[10] 4Runners.com regear group buy: Premier West Gear normal pricing around $2,500 for both axles, parts and labor.

^[11] WranglerTJForum regear cost thread: owner-reported shop quote around $2,400 for both axles.

^[12] 2005 GX470 factory manual, differential service specifications: drive pinion to ring gear backlash 0.11 to 0.18 mm (0.0043 to 0.0071 in).

^[13] IH8MUD speedometer recalibration thread: GX470 owner-verified SpeedoHealer install spliced into the combination meter speed signal wire.

^[14] Rough Country 90043 product page: listed for 2016 to 2023 Tacoma 4WD at $199.95; GX fitment not confirmed.

^[15] IH8MUD GX460 thread: GX470 owner towing report, 1,800 rpm in 5th at 65 mph too low for a 4,000 lb camper, targeting 2,200 to 2,300 rpm with 4.56 gears and 33s.

^[16] 2005 GX470 factory manual, differential service specifications: differential case to ring gear bolts 71 ft·lbf (97 N·m).