Solid-Axle Answers
Question: I have an '88 Toyota pickup with the IFS front end, and I want to swap in a solid front axle. But I don't want leaf springs, and I don't want to four-link it. Everybody and their brother has leaf springs where I come from, and doing a four-link is too complicated to do by myself. I want to coil-spring it, and I was going to use some parts out of a Ford Ranger or an F-150 (spring hangers, radius arms, and the crossmember that the radius arms go into). I have a few ideas on how to mount the front end, but I'm not sure how to do it, and I can't find anything on the Internet about it. Do you have any ideas?
Garrett M.
via 4wheeloffroad.com
Answer: Solid-axle swaps are much more common these days than just 10 year ago, and yes, leaf springs are the most common and easiest method for swapping a solid axle into a previously IFS truck, whether it's a Toyota mini-truck or a GM fullsize. I also understand your view that a four-link is too complicated. It takes a fair bit of work to get the links mounted in a way that works, clears everything, and allows for a safe yet agile off-roader. Your idea to use radius arms isn't bad. Many four-wheelers have used radius-arm suspensions with great success. Getting these parts from a Ford truck shouldn't be too difficult.
However, going from the Ford truck to your Toyota will be just as complicated as doing a four-link or a three-link with a track bar. When it's all said and done, it just might be cheaper since you can get these factory parts. Personally, I think the three-link with a track bar is the best option when using a steering box. The triangulated four-link works best with full hydraulic steering since it is complicated to make a steering box and a four-link suspension coexist without bumpsteer.
After those two choices, I would then choose leaf springs for simplicity and then a straight four-link suspension with a track bar. My final least-favorite choice would be the radius-arm suspension. Radius arms inherently bind during articulation, resulting in less wheel travel. That is fine for a primarily street-driven vehicle because the binding that hinders off-road use actually helps cornering and stability at speed--acting similar to a sway bar.
Now even though radius arms are my least favorite type of front suspension, they are fine for normal use. Be sure you replace worn bushings, get the track-bar and steering drag-link angles as close to parallel, flat, and equal length as possible, and make double sure your welding of frame mounts is strong. Radius arms apply multiple-direction forces on frame mounts compared to the single-direction forces found with four-link suspensions.
Locker-Steer
Question: I have a '97 Jeep Wrangler that has a 2-inch coil-spring spacer lift, a 1 1/2-inch body lift, and a Powertrax locker with 33-inch ATs. I started to notice that when I shift gears on the highway, the Jeep turns slightly to the left. I didn't know if the rear axle is loose or what so I checked it out and everything looks tight and not worn out. It seems to be getting worse. What should I do? I was thinking of removing the locker, replacing the lift with a real one, and changing out the bushings.
Wayne H.
via 4wheeloffroad.com
Answer: I've had this same thing happen to me. First, double-check that your rear wheels are exactly the same air pressure. The locker is causing this, because it recognizes a difference in speed from one tire to the other and is locking and unlocking at speed. If your tires are the same air pressure and the same size side to side, you shouldn't have any more issues. No need to get rid of the locker; you'll appreciate it later when you hit the trails.
Dis Traction Action
Question: I'm running Rockwells in a '77 Ford and the engine is pushing a little over 500 horses, and I need traction bars to help put the power to the ground. It's strictly a mud truck and won't see pavement or touch a rock. Can you please tell me the ups and downs of traction bars that mount directly from the axle to the chassis over ones that have a shackle attached? Four-link suspensions get thrown in the conversation a few times, but I don't really need that much flex.
Kasey
via 4wheeloffroad.com
Answer: Traction bars are for use with leaf springs, while four-link suspensions are for use when the spring cannot locate the axle, such as with coil springs, airbags, air shocks, coilover shocks, quarter-elliptic leaf springs, or leaf springs with shackles at both ends. A traction bar is designed to keep your axle from twisting or wrapping under throttle.
Axlewrap is the occurrence when the pinion moves in the opposite direction of the tires (for every action there is an equal and opposite reaction), usually under hard acceleration. If the axle wraps, the truck isn't moving forward until something binds like your springs, and oftentimes the driveshaft will bind before the springs. Then your driveshaft U-joint will break and you'll be getting towed home or laying in the mud fixing your truck.
The reason you want a traction bar with a shackle is because it will allow more suspension travel while still fighting axlewrap. As your axle moves up or down through the suspension travel, it also moves forward and back because it is mounted in the middle of your leaf spring--and as the leaf spring flattens out and the leaf-spring shackle swings, it moves that center point of the spring (where the axle is mounted) toward the front or rear of the truck. Since the traction bar is solidly mounted to the axle, it also moves toward the front or rear of the truck, so the frame end of the traction bar needs a shackle to allow this movement.