| Although a spring over is mostly simple labor, we chose to take a few extra steps in this conversion. As delivered from Toyota, FJ60s already have spring "perches" of sorts mounted above the axle. These are actually the u-bolt retaining plates. Wether or not they are used is up to the individual. In our case, we opted to actually remove the stock perches, gusset them, and weld them on top of the housings. Actually, almost everything was cut from the housings including steel brake line attaching brackets, shock mounts, and steering stops. Taking the time to remove these items assured that they would not interfere with the suspension once the springs were placed above the axles. Not only that, since the knuckles will be rotated and pinion angles changed, the position of the shock mounts and steering stops and other bracketry needs to be adjusted to compensate. |
| Here is All-Pro's Pete Bitto welding some 1"plate gussets to the stock spring perches. These gussets will keep the perches flat over time. Extreme wheeling, that causes the springs to invert, places excessive loads on the perches and over time, will cause them to round-off at the edges. Once the perches were gusseted, they were set aside for later. |  |
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| Rear Axle Preparation and Installation |
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Once the rear spring packs were assembled and installed to the chassis, it was time to prepare the rear axle for installation. The third member was installed and the axle shafts slipped in. The axle was rolled under the 'Cruiser on a floor jack and the spring perches temporarily set on the axle housing. It was time to set the pinion angle of the rear axle. With the axle under the springs, the rear tires were installed and the full weight of the truck lowered onto the rear suspension. To further load the rear end to realistic weights, the front end was lifted to make the wagon sit level. It is critical that the sprung weight of the vehicle being converted is as close to possible as realistic when setting the pinion angle. Jon sugguested that we shoot for setting the pinion within 2 degrees of the transfer case output flange. As the transfer's output flange's angle was about 3 degrees, the rear pinion was set to 5 degrees of upward rotation. We made some small adjustments and the perches were tacked in place. With the frame being supported by jackstands again, the tires were removed and the axle was then rolled out for final assembly and welding of the perches. A 1/4" plate was welded to the top of the perches to locate the leaf spring center pins. To be certain that the axle was free of debris, it was thoughoughly degreased and blown dry. Basically, the rear axle was completed and ready for installation once the finsh work was done and the exposed metal parts painted. |
| Front Axle Preparation and Installation |
One major item that sets apart a good spring
over job from a so-so one is the preparation of the front axle.
This key ingredient is what's known as cutting and turning of the
knuckles. In order to compensate for the new mounting postion of
the leaf springs (and the additional axle articulation afforded by
them), the ends of the axle housing where the steering knuckles
attach must be rotated to preserve a proper caster setting and
differential pinion angle.
The
knuckle ends are actually slipped into the axle housing and welded
into place at the factory. In order to be rotated, the factory
welds need to be ground and the axle housing needs to be cut
through to free the knuckle ends. The knuckle extend about 2 to 2
1/2" into the housing. The thickness of the housing is close to
1/4" thick. Careful placement of the cutting tool is critical. If
the housing is cut all of the way through, or too far to the
center, it is basically ruined.
Pete used a
large industrial pipe cutter for this task. Once the ends could be
adjusted, Pete took careful measurements of the knuckles' stock
position. Then, he rotated the knuckle ends approximately 1/4",
equivalent to about 12-15 degrees of upward pinion rotation. Once
satisfied with the positioning of the knuckles, the ends were
welded back up. 
In the meantime, the front springs were installed
to the chassis so that the front pinion angle could be
set.  |
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Setting pinion angle again depends on the placement of the spring perches. As was done in the rear, the axle was temporarily installed and set under the springs. Full weight was placed on the front axle and the pinion angle checked with a flat bar and angle guage laid against the back opening of the differential housing. After checking and double checking the angle, the perches were tack welded into place. Out came the axle again for a complete cleaning. Once dry, the spring perches were welded on and the steering knuckles assembled with new bearings and seals. The third member was installed, axle shafts slipped in, and the spindles bolted on. The front axle was ready for it's new home...UNDER the front springs! |
| Final Assembly Details |
| The final assembly was very straightforward. Basically it consisted of reassembling the parts in the order of disassembly, using any additional parts and/or upgrades as we saw fit. On the front axle, two different length u-bolts were used. This is because of the offset of the differential housing. A u-bolt retaining plate, taken from a front axle of an FJ40, was welded on to keep the u-bolts paralell to one another. This also gives a clean, stock look. |  |
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The steering system went together easily. All
Pro's steering arms replace the factory units and were installed
when the knuckles were reassembled during the reseal and
preparation of the front axle. The tie rod and draglink needed to
be custom made for length. The tie rod uses FJ80 rod ends that have
a 23MM thread. The draglink uses the FJ80 rod on the steering arm
(passenger) side and an FJ60 draglink rod end on the pitman arm
(driver's) side. This is because the FJ80 and FJ60's rod ends are
tapered differently. To attach the draglink to the pitman arm, the
ball stud was pressed out of the pitman arm and the FJ60 rod end
installed. This is in effect, the opposite of how the FJ60s come
from the factory where the ball stud on the pitman is attached to
the pitman arm via a rod end.
While
somewhat specialized, this method seemed to be the most simple way
of assembly, as we wanted to rule out fabricating a custom pitman
arm or modifiying one from a different vehicle. Again, this was
sticking to the goal of keeping parts simple to find should repairs
be needed. |
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| On the rear axle, 1/4" thick plates were welded to the tops of the sprring hangers to locate the spring's center bolt. We had accidentally threw away the rubber isolators that locate the center bolt in the perches...Moral of the story, don't loose these isolators! While it turned out to be a small problem, this was more of an annoyance than anything. |  |
| Driving Impressions |
|
Needless to say, we were very impressed with
the ride and handling of the FJ60 after completion of the spring
over conversion. It had a very smooth ride and soaked up
bumps well. Interestingly enough, body roll and sway in turns
was no more noticable (perceptibly from the driver's seat) than
before with the ~2.5" lift springs. Steering remained precise and
since the stock pitman arm was retained, bumpsteer was kept to a
minimum. This in part is also due to the near parallel angle of
both the tie rod and draglink. Shortly after completion of the springover, a Rancho steering stabilizer was installed. This addition further negated any perceptible bumpsteer. To mount the stabilizer, we torched off the stock stabilizer mount from the frame and rotated it 90-degrees to accept the pin-mount of the Rancho unit. The stabilizer and Hy-Steer can be seen mounted in the pictures below:  
Once the springover was completed it
was apparent that there was just a bit of fine tuning needed. While
the front suspension turned out to have the desired height, ride,
and flexibility that we were after, the rear needed some help. Our
initial guess of adding a single additional leaf to each spring
pack was a little off. Since the rear springs have settled, they
have begun to invert slightly, causing a definate sag. The
super-soft rear suspension also slightly effects handling on rough
paved roads and is especially noticable in windy conditions. We've
obtained a few more individual leaves from a Toyota pick-up to help
remedy the sagging and loose handling. The plan is to install one
leaf somewhere near the top main leaf and a heavier load leaf near
the bottom of the pack.
We were also happy
with the selection of shock absobers. The Doetsch Tech shocks offer
a a great ride with excellent sway control. Also, the simplicity of
no moving parts is a plus as well. |
| Final Thoughts |
| We have yet to take our project FJ60 out on the trails to see how it performs. That will happen shortly. Tune in next month when we'll have a full feature on the FJ60's debut trail ride. We'll be sure to note handling, wheel travel, and ride quality. We'll also follow-up on the additional work done to the rear suspension. See you on the trail! |
|
All-Pro Off
Road
581 North Palm #B3 Hemet, CA 92543 (909) 658-7077 Jon Bundrant - Owner |
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