Off-Road.com's Land Cruiser Tech - Toyota Land Cruiser FJ60 Spring Over

Sep. 01, 2005 By Jim Brink
Spring over axle conversions are not new to the off-roading community. For years, spring overs have been the main way of achieving suspension lift for drivers of Toyota Land Cruiser FJ40s, Jeep CJs, International Scouts, and just recently, Suzuki Samurais.

Spring-overs, quite simply, move the previously below-the-axle mounted leaf springs to above the axle. This swap nets a generous amount of lift without sacrificing ride quality or the use of heavily arched (and sometimes stiff) leaf springs. In most cases, such as in the vehicle we feature here, the stock springs are used for their smooth ride and flexibility.

This article will focus on the steps that are involved in performing a spring over axle conversion (SOA) on a Toyota Land Cruiser FJ60 wagon. There seems to be a growing interest in spring overs on these large wagons yet not a lot of information exists on how it is done and what parts are involved.

Not only that, there is only a handful of sprung-over FJ60s rolling around out there. For our example, we chose to use the best parts possible and sought the knowledge of those that have done this type of conversion in the past.

Since there are no "how to" manuals or instructions for doing a spring over (for any vehicle), the task of performing the delicate work was done by All-Pro Off Road in Hemet, California.

Known for their experience in building trail worthy Toyota trucks, 4Runners, and Land Cruisers, All-Pro handled all of the welding and fabricating required to do the job right. 

Why a Spring Over?
Why lift a vehicle to begin with? To get larger tires under it, of course! Bigger is better, right? Seriously, lifting a truck is just one way to improve it's trail performance.

The bigger the tire, the greater the ground clearance. A spring over is just another way to get that desired tire size fitted to the truck. 

On FJ60s, the largest practical tire that can be run when using an off-the-shelf spring lift is 33x12.50/15. While considered the absolute minimum for harder trails by some, 33" tires are a bit on the small side when one considers the weight of a fully-loaded Land Cruiser wagon.

Also, like we mentioned before, the larger the tire, the better the ground clearance. On a vehicle with as much rear overhang as an FJ60, ground clearance is at a premium to begin with. For the types of trails that the owner wishes to run, a spring over was the best choice when considering tire size, ground clearance, approach, and departure angles.

Aside from the amount of lift that a spring over yields (+/- 6" depending on the vehicle), utilizing this method of lifting allows the use of softer, flatter springs as the lift is not dependent on the arch of the spring pack. This leads to a supple highway ride and a flexy trail suspension. For our application, we used stock Toyota Land Cruiser FJ60 6-leaf spring packs front and rear. 

An added benefit of of the spring over is that it easily allows flipping the spring u-bolts to where the threaded portion sticks up instead of down as in the stock form. Having the u-bolts point up prevents the threads from becoming damaged and creates more ground clearance by eliminating one more item from hanging below the axles.

Prior to any cutting, we made several height measurements of our FJ60 so that we'd have a comparison of before and after results. One such measurement was on All-Pro Off Road's 20-degree ramp. Surprisingly, with 32x11.50/15 tires at street pressure and a 2.5" imported spring lift, the '60 ramped an impressive 940...Not all that bad. 

The height from the ground to the rocker panel below the driver's side door was also measured for an overall lift gain comparison. Lastly, we measured the distance from each fender opening to the top of the wheel rim.

This again would give un an idea of the actual lift gained front to rear, and side to side. Since leaning is a common problem in all Land Cruisers, we wanted to see if we eliminated this problem.

Before and after heights and ramp scores

PANEL
HEIGHT

  STOCK
SOA Conversion
  RTI SCORE
(20 DEGREE
  RAMP)
ROCKER
       940 17.25
      1005 24.25
Fender Seam to wheel well
STOCK LF-12.75 RF-14.25 LR-11.75 RR-12.50
SOA Conversion LF-19.00 RF-19.50 LR-16.00 RR-16.00

Although the RTI score did not increase considerably, it was apparent that the suspension articulated better than before.The rear tire was touching the base of the ramp and this was farther than we got before. We aren't finished with the truck yet, and we anticipate the RTI score to go even higher. The one thing limiting more upward ramp travel was the flexible brake lines.

Having yet to be lengthened for the extended lift by the springover, we were aprehensive to push too far. It was bad enough the brake lines looked like bow strings when the above picture was taken. We'll be taking another trip out to All-Pro shortly and as this article is being written, longer brakelines are in the works. Another item to keep in mind is the final measurements listed in the above table.

Not all of the kinks are worked out of the suspension yet, so don't take the before and after lift measurements seriously. In a follow-up article, we'll have some updated information once we're satisfied with the suspension.

Parts Used

There is no "grocery list" that exists as a guide for spring overs. Actually, not a lot of parts are needed to complete a swap like this one. However, it was decided early on that this project was going to be done correctly, the first time.

With that said, a basic parts list was made, citing not only safety concerns but also those that would enhance performance, both on and off road. 

Parts: Steering

With the exception of the steering box, pump, shaft, and lines, all stock steering components were replaced. Since Land Cruiser FJ60s already utilize a "crossover steering" system from the factory, not a lot needs to be done to enhance steering feel and performance.

But, one such modification is available that is not only practical but ranks VERY high on the "coolness" scale: Hy-Steer. All-Pro's Hy-Steer moves the steering's tie rod up above the springs, keeping it up away from rocks and obstacles.

The heart of the Hy-Steer system is the steering arms themselves. Made from investement-cast 4130 chromoly, these arms replace the factory pieces and retain the tapered cone washer mounting holes and accept stock tie rod ends.

Both the tie rod and draglink were replaced and upgraded at the same time. Using larger-than-stock diameter 1.125" o.d., .188 wall DOM seamless tubing, it's doubtful that these parts will bend when placed against the stresses of rocky terrain and low-geared, locked differentials. 

A combination of Land Cruiser FJ80 and FJ60 parts were used in the steering system. The goals set when building the steering system were simple: Maintain good road manners, strengthen the assembly, prevent trail damage, and keep the system simple enough so that parts remain available and easy to obtain should breakage occur.

We'll cover more of the Hy-Steer's detail a bit later.

Hy-Steer is available for sprung over Land Cruisers that use post-'79 steering knuckles.

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