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The $4k Toyota 4Runner - Part 3

Toyota 4runner Wheeling
Harry Wagner | Writer
Posted September 23, 2013

Gearing & Traction for a Tough Trail Toyota

In the first installment of our $4K 4Runner we added suspension products from 4Crawler, Daystar, and Rancho to stuff 33-inch BFGoodrich All-Terrains under the fenders (May ’13). The tires fit now, but even with the factory 4.56 gears the “3.slow” engine has trouble turning them. Fifth gear might as well be the tooth fairy; we had heard of it but never actually seen it.

“Fifth gear might as well be the tooth fairy; we had heard of it but never actually seen it”

To remedy this issue, we made a call to JT Parts & Accessories for 5.29 gears and new bearings for our Toyota. The horsepower peak of the 3.0L is at 4,800, and the torque peak is at 3,400, so we wanted to keep the engine in that range on the freeway. With 4.56 gears and the stock 30.5-inch-tall tires, the 4Runner was turning just over 3,000 rpm at 75 mph. 5.29s bump the rpm up to 3,280 at 75 mph, just below the torque peak.

$6K 4Runner?

Our stated goal with this project was to perform $4,000 worth of upgrades to increase the trail prowess while maintaining reliability and good road manners. We met those goals but blew our budget in the process. Looking back, where could we have saved money to stay on budget without making too many compromises?

  • Run Rancho RS5000 shocks instead of RS9000XL shocks ($240 savings but no ability to fine-tune ride).

  • Forfeit fullsize BFGoodrich spare tire ($149 savings but stock spare tire was too small to use on one corner of locked axle).

  • Wait to purchase Trail Gear Rock Defense rear bumper ($299 savings, but stock bumper had no recovery points and poorer ground clearance).

  • Use Smittybilt XRC 8 winch instead of X20 8 winch ($100 savings but not waterproof).

  • Hold off on Budbuilt rear belly pan ($279 savings, but transfer case would be vulnerable off-road).

Step By Step

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  • Our 4Runner uses a 71⁄2-inch differential in the front. We needed to match the gear ratio with the rear, but we refrained from adding a locking differential for two reasons. One, we didn’t have the money in our budget, and two, we were concerned about the strength of the front-end components.

  • The 8-inch differential in the back of our 4Runner is incredibly common; it is still in production after more than three decades. This makes parts easy to source and reasonably priced. We pulled the centersections ourselves to save on labor for the gear installation.

  • Aaron Lechner of Bayshore Truck normally works on over-the-road trucks, so our little Toyota was a piece of cake. Although we are on a budget, setting up gears was one task we felt was best left to hired professionals with specialized equipment.

  • Having equipment like industrial parts washers is one of the advantages the pros have over doing the installation at home. Bayshore thoroughly cleaned all components and painted the centersections before we reinstalled them.

  • In addition to the Nitro Gear & Axle ring-and-pinions, JT Parts & Accessories also supplied us with new Koyo bearings and seals for both the front and rear differentials. With 190,000 miles on the clock it was cheap insurance while Bayshore was in the diffs.

  • Nitro Gear is the only manufacturer to offer aftermarket gears for Toyotas with 29-spline pinions, the same as found from the factory on ဲ’01-plus Toyotas. Other companies require you to retrofit the older and weaker 27-spline pinion, but not Nitro Gear. We upgraded our ’94 4Runner for added strength.

  • The new Nitro pinion flange is required with the 29-spline pinion. It has multiple bolt patterns so Bayshore did not have to make any driveline modifications.

  • The bearing caps were punched prior to disassembly to ensure that they were installed in the same location and orientation.

  • If we were not changing the gear ratio the Powertrax Lockright could easily be added at home with common handtools. The Lockright fits inside the open carrier, replacing the spider gears, and provides full traction to both rear tires.

  • JT Parts recommended that we swap out the factory crush sleeve for a solid spacer and shims. This allows us to remove the pinion flange without concern about the preload changing. Lechner measured the crush sleeve that came out of the diff as a starting point for the overall length of the new solid spacer and shims.

  • Since we already had the rear axleshafts out, we took the opportunity to replace the rear wheel bearings and seals. They weren’t leaking, but they were the factory Toyota pieces with nearly 200,000 miles on them. Bayshore built a special fixture to accomplish this; they can be a challenge at home, even with a press.

  • Bayshore capped off the rear differential install with a LubeLocker gasket and Lucas gear oil. The LubeLocker is a reusable gasket with a steel core that is rubber coated and has full perimeter elastomer beading on both sides of the gasket to prevent leaks.

  • The lower axle gears have been a welcome addition on the street and the trail, while the Lockright has provided additional trail prowess at a reasonable cost. That is what the $4K 4Runner is all about.


Chicago, IL 60609
Nitro Gear & Axle
Sacramento, CA
Lube Locker
JT'S Parts & Accessories
Bayshore Truck Equipment Co.