Crossover
Steering
In doing the solid axle swap, All Pro Off Road made the front suspension on my truck very similar to the suspension found on 1979-85 Toyota trucks. One change that was made is something called crossover steering.. This is a steering system used on many other trucks, including some Toyota Land
Cruisers.
The original 85 truck/4Runner style steering system used a U shaped left side steering arm that is prone to breakage and limits suspension travel. This type of steering system also has a lot of play in it, making steering feel loose and sort of disconnected. I also wanted to move my axle forward 1" to increase clearance between firewall and tires, the original draglink
makes this more difficult.
 
With the crossover steering the pitman arm connects directly to the passenger
side steering arm via a drag link. Then a heavy duty Marlink tie rod connects the steering arms together. When we installed the steering at the shop we used one of All Pro's hand made steering arms as
pictured in last months article. These units can be made to accommodate different amounts of lift and to change the quickness of the steering. I later exchanged the steering arm for one of their cast units pictured above. The cast unit I am now using has a slower steering raito allowing for more "feal" but also requires more turns of the wheel. I also believe this will place less stress on the steering box as the wheel is now easier to turn. The cast unit allows the drag link to be attached to the top or bottom of the top fork of the arm to get the best draglink angle. "S" shaped draglinks can also be made to accommodate most any lift. Currently, my drag link-to-tie rod angle is very small, eliminating bump steer common with some crossover steering
systems.
 
Mountain
Driveline front drive shaft.
The front IFS drive shaft was not going to work on my truck after the swap. I knew this from the start, but after the 85 axle was installed, I climbed under with the old drive shaft in hand just to see if it would fit. There was not enough droop in the CV joint to allow it to bolt up, not even close. I ordered a rebuilt and lengthened 85 front drive shaft to fit. This allowed the front axle to move and flex as it should with while still getting power from the transfer case. I can see the limits of angle here though. With the front 4" lift springs and stock shackles. I have reached the droop limits of even the 85 style drive shaft. With the front of the truck lifted in the air and the axle allowed to hang I can feel the CV joint just starting
to bind a little.
I also found an interesting thing when I compared the front shaft flange assemblies. Both the '93 IFS and the '85 have the same travel in the slip joint, but I noticed the '85 front flange starts to bind at an angle of 20 degrees but the flange and U joint on the IFS drive shaft allowed up to 40 degrees of deflection before interference becomes a problem. The '85 style drive shaft has a more flexible rear CV joint and the original IFS drive shaft has more flexibility in its front U joint and the slip joints are the same, so I ended up using a hybrid unit. The back half being a lengthened '85 style and the front half being my original IFS flange and U joint. Both flanges pictured here are angled as far as they
would go. The '93 IFS on the left and the '85 on the right.
Front bumper mount Modifications.
My front TJM bumper was designed as a two piece unit. The first piece bolts onto the front frame rails and then the bumper attaches to the mount. After the leaf springs were installed the front spring hangars prevented the reattachment of the bumper mount. I had All Pro cut out the bottom
part of the bumper mount so that the mount could again slide on. The bumper mount used 2 holes on each front frame rail as part of the mounting. After cutting off the part of the mount these attachment points could no longer be used. As an alternate mounting point, I welded a 3" wide strip of 1/4" plate steel on the front frame crossmember. I then drilled 5 holes along the strip and through the mount. This allowed the use of 5 bolts
to hold the bottom of the bumper.
 
Wheel
offset and spacers.
I choose to use 8" wide 4" offset American black spoke steel wheels. Using the 4" offset keeps the tires under the fenders a little better than the '85 factory
3.5" offset. This wheel is also working well on the rear suspension and has eliminated rubbing problems between the tire and frame that I had with previous 4.75" offset wheels. When used with the All Pro front 1.5" wheel spacer kit there is plenty of room for snow chains. This kit makes the front axle
about the same width as the normally wider rear late model rear axle.
  
Road Testing and
Evaluation.
I have had the solid front axle for about a month now and have driven it about 1,000 miles on the highway and offroad. I tried it out on a few local trails and then went with a group to Ballarat. I have not yet put in a front locker, but have not missed it so far on these types of trails. The added flex of the suspension keeps the wheels on the ground and traction has not been
a problem, but a Detroit locker will be added soon.
The ride on the highway is a bit different than the old IFS . For comfort IFS is hard to beat. It is very difficult to compare the ride quality of the IFS and leaf spring systems because it's quite different in many ways. A better comparison would be something like a factory solid axle 4Runner (84-85 model). The crossover steering system has much less play than the factory solid axle steering and less play than the IFS did. The highway ride quality afforded by the Alcan springs is wonderful. This is the second set of springs I have had on the truck. The first set were designed for a '85 truck but the greater weight on my V6 and 4Runner body style rendered the first springs a little too soft. I weighed the truck and found it to weigh 5040 pounds. Jon at All Pro ordered a special set of springs just right for my truck. Each spring pack has 6 leafs and each leaf is 7 mm thick. Alcan springs can be ordered with any combination of 6 or 7 mm spring with 5 or 6 leaves per pack. That gives you a lot of different combinations of springs that can be made. If you are looking for leaf springs for your Toyota, give Jon a call. He can order just
the right spring for your truck.
Offroad driving with the new solid axle is every thing I expected and more. While at Ballarat this month I had a chance to test the truck on a decent trail. On this run there were several points where I could see the truck in front of me pick up a wheel from time to time. At one point I was following my Dad's truck and you could see he had about 6" of air under one tire and his truck was a little tipsy going over that set of rocks.
When we went through the truck stayed level and never lifted a tire.
Thanks again to Jon
at All Pro Off Road, and the wonderful job with my conversion.
Broken steering arm picture courtesy
of
Jay Kopycinski
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