The Turtle V – Update #2 – Tires, Wheels, Steering, Bearings & Fender Flares – 2019

The Turtle V project was full of challenges. First, we had to get rid of the dual rear tires. Duals don’t work on rocky roads and they plow sand, mud and snow.

 

 Michelin XZL’s and Rickson steel wheels

After some experimentation, we chose Michelin XZL 335/80R20s and mounted them on custom 20X11 Rickson steel wheels. Michelin is the only tire company that makes anything like the XZL. Its ability to carry a full single axle load of 7,540 lbs. at 50 psi or even less without overheating is unique. It handles highway speeds of 70 miles an hour like any mud and snow tire and we can drop the pressure down to 25 psi or even 15 psi without bead locks. Despite the XZL’s aggressive tread, we still carry Pewag mud & snow chains for both front and rear axles. The Rickson wheels can be reversed to run on front or rear and still track in line. Valve stems on both sides facilitate airing up and down.

The perfect answer: Warn Drill Winch 

Getting the 197-pound wheel and tire down from our custom mount on the rear of the camper was easy. A 2’ draw bar slips into a receiver on the roof and a Warn Drill Winch lowers the tire to the ground using a 14-volt cordless drill for power. The Warn Drill Winch can lift over 500 pounds.

SmarTire system

Before we mounted and balanced the tires we installed a SmarTire sensor/transmitter on each rim. As we drive, the SmarTire receiver on the dash tells us the pressure and temperature of each tire and warns us if anything suddenly varies from preset perimeters.

 

MOOG tie rods and LEE Power Steering

Steering with the big 40.7” tires was not really a problem, but to take the load off the MOOG tie rods, drag link and the idler arm bushings, we had a custom LEE Power Steering pump engineered with a remote reservoir for better cooling and a full ram-assist system which eliminates the need for a steering shock absorber.

Dynatrac’s Free-Spin™ Heavy-Duty Hub

The first big mechanical challenge was the ongoing problems with Ford’s unit bearing on the front Dana 60 axle. Clearly designed to speed up assembly times, both Timken and TRW knew there would be problems. Fortunately, the easy fix was Dynatrac’s Free-Spin™ Heavy-Duty Hub Conversion Kit. It was designed to replace the factory unit bearings with fixed spindles for superior strength, and smooth performance. It uses Timken bearings that can be found all over the world and can be adjusted and serviced by any mechanic.

Custom Bushwacker Flares

With the bigger tires, fender flares were necessary. We basically ramped up the truck to see what hit and cut it away. Bushwacker digitized the cut out and made custom flares. The rear flares were easier. We just built the camper to fit the 40.7 inch diameter of the XZLs, allowing room for suspension travel and mud and snow chains.

Filed under:
Tech Stuff, Vehicles by Turtle Expedition