Suspension Bush Replacement Guide
One of the best changes you can make to improve the handling and responsiveness of your track car is to replace your suspension bushes. If possible, you should try replacing them with a polyurethane bush, as these deflect less than standard metalastic factory bushes and are easier to replace in the pits without the need for special tools. We stock SuperPro bushes in the store, I personally only ever fit SuperPro bushes as these are the best of the best in my opinion.
However, to remove the old factory bushes can be sometimes quite difficult. Because they are made from a dense rubber sandwiched between two metal races, the outer metal layer can sometimes corrode and become stuck to the control arm or hole it is positioned in. Here we've listed 5 DIY methods for removing your factory bushes.
Cut and Punch Out The Bush
This first method is time-consuming and hard work, but sometimes, especially if you're stuck away from your garage, it is the simplest method. The idea here is to cut the inner bush race or crush tube using a bi-metal hacksaw. You then also cut through the bushing material and the outer metal sleeve. Then, you use a drift punch and hammer to first knock out the inner race and the rubber, before carefully folding the outer race in on itself. Sometimes you get lucky and the bush will fall out after only a short time of hammering, other times it will fight you right to the end. Make sure to hammer your control arms on a cloth or a piece of wood so as not to damage it!
I have seen people use a hole saw to cut through the rubber as near to the outer race as possible, this might save you some time and is worth a try.
You do have to be careful when using this approach that you do not accidentally cut into the control arm itself, causing a burr that could damage your polybush or even a weak point that might fracture and crack.
Bush & Bearing Puller / Press Tool
This is the best method for replacing control arm and trailing arm bushes, using a bush puller tool or press. These tools are not terribly expensive and are useful additions to your toolkit. Often, they are supplied in a neat blow molded case for easy transportation.
Using a bush puller is very simple and is the safest and cleanest way to remove a bush. First, you need to get the correct size receiver cup for the bush to be pressed into. This needs to clear the outer race of the bush and sit squarely onto the body of the control arm. Then, you push through the threaded rod for the tool and add a washer and nut on the end of the receiver. On the other side of the control arm leg, we fit a press that is sized to contact only the outer race, but that will still clear the hole in the control arm. Another nut and washer are added, and you simply tighten down the tool until the bush is forced into the receiving cup and out of the control arm hole.
This is the most controlled way to do it and the tool is also used in refitting the bushes. When reinstalling, it's a good idea to clean the hole and apply a light coating of general grease to the bush sleeve to help ease it back in. You can pick a set up for as little as $50.
Another tip, on some control arms or wishbones, it is a good idea to put something between the two walls of the control arm so it doesn't deform at all. A piece of pipe cut to length or even a socket would work well.
Home Made Puller
The commercially available press and puller kits work on a very simple concept and you can make your own if you want to save cash. All you need is some threaded rod or studding, a couple of thick washers and nuts to match the stud thread. You also need to find something suitable to press onto the bush outer sleeve and something to push the bush into. I've seen people use hole saws for this and even impact sockets. You could also use a bit of steel pipe. By turning the nuts together, the bush is pressed out. Smear a bit of grease onto the thread to help keep them in good shape.
If you plan on using the tool a lot, a length of acme thread or a worm screw will be the strongest option.
On some control arm bushes, you may be able to press the bushes out using a shop press. Using a number of arbor plates and adaptors, it's possible to create the necessary void to push out bearings. This method works, but it's easy to damage the control arm with a hydraulic press. Also, as most control arms are 'A' or 'C' shape, it can give you a bit of a headache trying to orient everything to press it in the right direction.
The cowboy or 'bush' repair method, simply burn them out. This creates a thick black smoke and gooey molten rubber which are a personal and environmental health hazard. Not recommended! You still have to remove the outer race using a drift punch too! Bushes will burn forever, even when using a blowtorch and so it's pretty slow going.
We hope this post helps you when replacing your own bushes. Definitely give polyurethane bushes a try, they'll transform your track cars ride. The difference they make is quite amazing and very immediate!