Suspension/Control Arm Bushing Replacement

This article describes how to replace the suspension/control arm bushings on a Jeep Wrangler TJ. Oftentimes, these bushings can become worn out and then make a clunking sound when you go over bumps. This is common in the TJ series and is difficult to identify the bushings as the cause. This article shows how to replace the front, upper control arm bushing on the driver's side.

Finding The Bushings

There are 16 similar bushings on your Jeep - 4 on each corner with 2 for the upper and 2 for the lower control arms. When purchasing replacement bushings you have the choice between stock or polyurethane. In this article, I'm installing a stock bushing that I purchased at Car Quest in Cedar Springs, Michigan. The CarQuest part number for the upper bushings is K3166 and the lower bushings are K7420. There are two part numbers because the bushings are different sizes with the upper bushings being the smaller size.

Tools

So, what will you need in the way of tools? Unfortunately, this is not a simple bolt-off/on application. It will take some effort and maybe a little bit of cursing to get the bushings out. There are a few methods that I've tried or seen documented to remove the bushings.

One method is to take a torch and melt them out. This is not a pleasent experience and I consider it dangerous considering that the upper bushing will still be connected to your Jeep while you're trying to melt it off. The combination of an engine filled with highly flamable contents (oil & gas) plus a torch doesn't sound like a safe way to spend an afternoon. If the bushings were out of the Jeep then this might be an option.

Another approach is to drill small holes around the bushing to loosen the rubber. After almost all of the rubber has been drilled out you can use a chisel to crunch the sides of the bushing until the bushing slides out. The problem with this approach is that there isn't much space to work once your under your Jeep. Trying to get a good whack at the bushing is nearly impossible.

Another method described in the Chiltons and Haynes manuals is to use a piece of all-thread (threaded-rod) and two appropriately sized sockets. I tried this approach and the one problem is finding a socket that is just the right size to be larger than the bushing, but smaller than the bushing perch. Another issue is the price of the sockets since you'll need two of them because there are two sizes of bushings. And lastly, it didn't work for me. The amount of torque it takes to get the bushings out was much more than the 3/8" all-thread could handle. A larger all-thread can't be used because it won't fit down the middle of the bushings. Perhaps, if you have access to grade-8 all-thread this might be an option.

And lastly, if you look at the Jeep Service Manual a specialized tool is described. The service manual mentions part numbers 7932-3 (spacer), 7332-1 (receiver), 7932-2 (remover/installer tool), 7604 (bolt) and 7603 (nut) as the group of tools to remove the bushing. I've checked many sources and could never find this tool. I can find very expensive kits ($500) that provide various remover/installers for several makes of bushings, but the price makes these impractical.

The method that I'm suggesting here involes purchasing a $30 tool from Harbor Freign and then a $2 part from a hardware store. Then, spend a little time with a cutoff wheel and a hammer. The $30 part is called a 3-IN-1 Service Kit.

Tool Fabrication

To fabricate a tool to remove the bushing, get the 3-IN-1 Service Kit from Harbor Freight. The kit costs about $30 and can be used to remove bushings, ball-joints and tie-rod ends. The important piece of this kit is the C-frame press. The kit includes 3 receiver tubes. The 2-3/4" tube will work for the lower bushings, but the 2-1/4" tube is just a bit to small to work for the upper bushing. We'll need to fabricate a receiver tube for the upper bushing.

To fabricate the receiver tube for the upper bushing, go to the hardware store and pick up a 2" black pipe coupler. Then, cut the coupler in half and open it up until the bushing just fits inside.

To cut the coupler in half, I used a cut-off wheel attached to an air tool. If you don't have an air compressor, I've also attached the cut-off wheel to an electric grinder with good results. Once the cut was made, I used a hammer and my bench vise to spread the coupler open.

Spread the coupler apart until the bushing fits inside the coupler without binding. This image shows how the coupler and the C-Frame are used. I also used some appropriately sized washers on the threaded-rod side of the C-Clamp. I used grade-8 washers since they will with-stand the torque.

Removal Steps

The first step is to jack up the Jeep. I jacked up the entire front end and placed jack stands behind the front tires on the frame rails. I usually keep the jack under the car just as a third point of safety in case one of the jack stands has a problem.

Next, remove the upper control arm by first removing the rear-most bolt. Notice how the bolt is connected to a hidden nut with a handle. Make sure you keep track of the nut when it falls out after the bolt is removed.

Next, remove the bolt holding the front of the control arm. The control arm can now be removed from the Jeep. The control arm will have one bushing attached to it. The removal of the bushing on the control arm will seem simple after removing the one attached to the axle. This bushing is still attached to the car.

Setup the C-Frame and the coupler as shown below. I used a grade-8 washer on the left hand side between the C-Frame's threaded rod and the bushing. Careful not to use a washer that is too small because the rubber will just compress. I suggest picking up a collection of these washers when you're at the hardware store so you can play with the sizes. They are cheap so get a few.

Use your socket driver on the C-Frame's treaded rod and just keep cranking until:

POP! The bushing pulls out. The bushing won't slide out a little at a time. It will just all of a sudden pop out.

Now, you're ready to remove the bushing that is still connected to the control arm. I won't go into details about this removal since it is very similiar. The only difference, if you want to use the C-Clamp method, is to use a spacer between the control arm sides so the control arm itself doesn't compress.

Reinstallation Steps

Reinstallation of the bushing is very similar to removal. Before moving forward, use a piece of sandpaper to clean-up the inside of the bushing perch.

Then, apply some assembly lube to the bushing

Attach the C-Frame to reinstall the bushing by placing the receiver tube on the opposite side of the bushing. Then, slowly crank down on the threaded rod.

Until the bushing is reinstalled.

Lastly, reattach the control arm to the Jeep and you are all done. The control arm bolts should be torqued to 55 foot-pounds using a torque wrench.

If you are replacing the lower control arm then torque the nut on the axle to 85 foot-pounds and the other nut connected to the frame to 130 foot-pounds.

I was very happy to find that this took care of the clunk that I heard when I hit a bump hard. Replacement of the bushings is not the silver bullet for all suspension clunks because there are many, many other parts that can cause noise, but this is a relatively simple fix that doesn't cost much.

Let me know if you have any questions.