Isuzu Torsion Bar Adjustment

This article is to help those that are unfamiliar with IFS (Independent front suspension) style trucks raise the front end of their ZU.

The tools needed:

½” ratchet or ½” breaker bar or a ½” impact wrench

½” drive 27mm socket (1-1/16” works too)

Cheater bar (piece of pipe to slip over the handle)

Jack stands

Floor jack

Penetrating oil

Measuring tape

Before you try to do this, spray the threads of your adjuster bolts several times. If they are very dirty hit them with a wire brush then oil them. These can be tough on older rigs like my 88 Trooper was.

Lift the front of the truck a bit with the floor jack, not necessarily off of the ground but enough to relax the torsion bars. Put the jack stands under the frame. Never work under any vehicle with only a jack, always use jack stands.

Next to find your adjuster bolts, look at the lower a-arm and you will see a bar coming out of the back of the a-arm (about an inch in diameter - see pic below) called a torsion bar (this is your front spring) follow it back to the cross member where there is a large bolt head on the underside of the cross member. This is your adjuster bolt for your torsion bar:

Here is the torsion bar where it comes out the back of the lower a-arm:

Here is the other end of the torsion bar where it goes into the adjuster:

To lift turn it clockwise, to lower turn counter clockwise. You may need to use a length of pipe to add some leverage. These things can be a bear if you are working on an older rig. My 88 Trooper drivers side adjuster was frozen solid. I broke a ½” Craftsman ratchet like it was nothing. I ended up using a ¾” breaker bar and about a 4’ piece of pipe. A rule of thumb is 4 complete turns is an inch of lift. This will vary from truck to truck depending upon the condition of your torsion bars. I used the impact wrench method (once mine broke loose) so I didn’t do much counting of turns.

Drive around some bumpy areas to let the springs settle in a bit then re-measure. Adjust as necessary. Drive for a few days and measure again. Adjust if necessary. Go get an alignment. Your tires will probably look like \--/ This can and needs to be fixed at the alignment shop.

This should be all anyone should need to adjust your own torsion bars. There are some cases where you may run out of threads to adjust, you will in these cases need to “re-index” your torsion bar(s). This isn’t typically necessary. To re-index you have to take your t-bar adjuster completely loose and take the t-bar out of where it attaches and rotate one end to pre-load it. Then adjust it as necessary.

I hope this helps some people become more familiar with their trucks and gets them into their driveway or garage instead of a 4x4 shop.

Isuzu Ball Joint Flip/Spacer Howto

Ball Joint Isuzu

Warning: This is only for NON Rack & Pinion Isuzus. This means that 98+ Amigos, Axioms and some late model Rodeos are out until another solution is found.

First, some background:
On modern Isuzu IFS suspensions, the Upper Control Arm (UCA) is what limits suspension down-travel. There is a bump-stop located under it that it contacts as the wheel assembly moves down. Up-travel is limited by the lower control arm contacting a bump-stop that is located on the frame. We don't deal with that in this article.

The purpose of this modification is two fold: Increase suspension down-travel, and improve the alignment after lifting. When the torsion bars are cranked, some amount of negative camber is induced into the steering geometry. This is just due to the design of the IFS system. Under ideal circumstances there should be a slightly negative camber. Too much negative camber will cause uneven tire wear, and will also decrease the traction, mostly during cornering due to the tire having a poor contact patch.

By flipping the ball joint, or flipping it and using a spacer, the camber is moved back toward the norm, which is much closer to 0. Depending on your specific setup, it may go back to perfect alignment, or not, but you should have the truck aligned after front end suspension changes anyway.

Disclaimer: Suspension modifications are done at your own risk. Please check bolt torque and component wear while you are making changes. The picture quality here isn't great, but it should be clear enough to use.

First of all, the stock setup has the upper ball joint bolted to the top of the UCA. The part that connects to the spindle extends down through a hole in the UCA and through the spindle, where there is a castle nut and cotter pin. In the next picture you can see the upper ball joint bolted to the UCA and still attached to the spindle:

The first step is to jack the truck up and support the frame on jack-stands. If you only have one jack you will need it later to jack up on the suspension when you are putting things back together. Jack-stands are cheap and keep things safe.

Next, remove the cotter pin and then the castle nut that holds the ball joint into the spindle. A large box wrench works well. If the cotter pin isn't in good shape, spend $0.25 for a pair of new ones. Needle nose pliers work well to straighten and remove the pins.

The next step is the one that takes the most courage. You are going to have to wail on the spindle. The ball joint has a tapered shaft, and the spindle has a tapered hole. These over time will become VERY tight (which is a good thing for the suspension), but that makes it hard to remove. Use the hammer, or a 5lb sledge if you have one to hit the spindle. BE CAREFUL. The spindle and lower control are have spring pressure pushing them down. When the ball joint breaks loose the spindle will drop 1-2". Keep everything, including yourself, out from beneath it.

Here is what it will look like then the ball joint comes free from the spindle:

The next step is to unbolt the ball joint from the UCA. There are 4 12mm nuts and 12mm bolts. They won't be very tight, but as always be careful not to strip them.

Next just grab the ball joint and lift it out:

After that, set the ball joint back into the hole in the spindle. Make sure that the two surfaces are clean and dirt free. Now is a great time to grease the ball joint, or better yet, replace it. If you are using a spacer, certainly grease it now because the grease fitting will be impossible to reach once the system is back together. Put the castle nut on the bottom of the ball joint, finger tight for now.

You will need to use the jack under the lower control arm to raise the spindle up enough to reach the UCA.

If you are using a spacer, install it now. You will need longer bolts if you are going to use a spacer. If you are just flipping the ball joint, the stock bolts can be reused. Assemble them finger tight first to get all 4 holes lined up. Sometimes a screwdriver in the holes will help bring the ball joint into alignment under the UCA. Tighten the bolts to the correct torque spec.

The last step is to tighten the castle nut on the bottom of the ball joint. This one should be tight. Check your service manual for the actual torque spec. When it is tight, make sure that the hole in the ball joint lines up between 2 of the ears on the castle nut, then insert the cotter pin and bend it over.

That is it. Take it to the alignment shop, and enjoy the fact that the truck is better aligned, and has more suspension down-travel than it did stock.