How-to Properly Burn Out Rubber Suspension Bushings
Not many people have access to a hydraulic press. So what are your options for removing a suspension bushing? Burning them out tends to be mentioned often, but many people do it wrong. This article will go into detail about how to properly remove OE suspension bushings using a torch. In the article we’ll detail:
If you don’t like to read, you can watch the video below.
A Word of Caution!
Take a minute to read the comments below before you get started. You’ll read of a frightening experience where a commenter was burned while removing a bushing. While we dont know the exact cause of his experience, the technician at Prothane has speculated that it’s possible that he was working with a fluid filled bushing. Apparently these bushings aren’t very common in the automotive suspension world, but we would suggest that you check yours first before trying to remove the bushing using the heat of a torch. We have no experience with these bushings so we cannot advise you concerning them, but if it were me it might make sense to perhaps use a drill to cut a hole through a bushing before getting started to see if anything leaks out of it. These instructions are for use on solid rubber bushings. If you have any suggestions for working with fluid filled bushings we would love to hear from you in the comments below!
Burn ’em Out
“You can burn out your OE suspension bushings.” You’ve probably read this in a lot of places, and you may have even watched a video on how to do it. But there is the right way to use a torch to remove bushings, and the wrong way.
There’s the right way to use a torch to remove bushings, and the wrong way.
The right way will leave you with a pretty simple and clean method of removing a bushing. The wrong way isn’t just dangerous and inefficient, it also leaves you with a lot of smoke, a foul odor and flames.
Keep in mind that any time you’re using power tools and fire, you should exercise caution and wear appropriate protective gear.
The Right Way: Heat up the Housing
This method is designed for rubber suspension bushings. Polyurethane bushings dont need a torch and a fluid filled bushing would be dangerous to remove in this manner. The correct way to remove a rubber suspension bushing with a torch is to slowly heat up the bushing from the outside. Using the torch to heat the housing that contains the bushing will eventually cause the rubber to boil, breaking its chemical bond with the outer metal shell. The melting point of rubber is about 350 degrees Fahrenheit, so all you have to do is heat up the outer housing to transfer 350°F to the bushing, thereby causing it to boil. NOTE: This process takes several minutes to accomplish. Keep the torch on the housing until the rubber begins to boil. Apply the torch to all sides of housing to heat all sides of the bushing. By applying that heat through the housing, you will protect the rubber from actually catching on fire. You don’t have to get the housing cherry red hot and risk damaging the arm, it just needs to be hot enough for the rubber to boil. Speaking of boiling rubber, make sure you wear long sleeves, gloves, and eye protection.
Using the torch to heat the housing that contains the bushing will cause the rubber to boil, breaking its chemical bond with the outer metal shell.
Push out the Bushing with a Metal Tool
While the rubber is still hot, you can easily push out most of the bushing by pressing on it with a metal tool of some sort. BE VERY CAREFUL when you push the bushing out. The rubber is very hot (duh it’s boiling). You don’t want it falling and hitting your arm or leg or your dog. So take the proper precaution when pushing the hot rubber bushing out.
You can easily push out most of the bushing by press on it with a metal tool of some sort.
Remove the Excess Rubber
From there you can char the remaining rubber and use a wire brush to clean out the charred bits.
Use the torch to char the remaining rubber.
Use a wire brush to clean out any charred bits.
The Wrong Way: Melt the Bushing
Burning a rubber bushing isn’t simply excessively messy and dangerous, it’s also extremely inefficient. Instead of simply heating the rubber up, you’re actually trying to consume the rubber with flame. That’s about as smart as removing a tire from a wheel by setting the tire on fire. It would work, but it isn’t very efficient. Additionally, rubber that is on fire can “pop” and “spit” little flaming balls of rubber “lava”. If you’ve ever been hit by that, you likely remember that painful experience.
SUPER IMPORTANT: Should you remove the OE Outer Metal Shell?
This is the point where you need to stop and use your brain for a minute. Most aftermarket suspension bushings require the use of the original metal shell. The bushings are engineered in a two piece design for a DIY friendly installation. Each half bushing pushes in from either side INTO the OE SHELL. So before you get your hacksaw out, check the installation instructions with your replacement bushing. Once you remove the OE shell, there is no getting it back in if you need it. If you have any questions or trouble figuring out whether you need to keep your OE sleeve in, give our DST part’s experts a shout and they can help you avoid a big mistake.
If you need to reuse your OE metal shell, you can stop right here. If your new bushing has a new metal sleeve with it, keep reading to learn how to remove your OE metal shell.
Removing the OE Outer Metal Shell
Relieve the Tension with a Hacksaw
If and only if you are absolutely sure that you do not need to leave the outer metal shell in the housing (see above paragraph), you can go on to the next step. AFTER YOU HAVE COOLED THE HOUSING, whether by immersing it in water or letting it sit for a while, you can use a hack saw to cut a thin line through the outer shell to relieve the tension against the housing.
Slide your blade into the housing and attach it to the hacksaw.
You must be exceptionally careful not to cut into the housing itself. You only want to cut the old bushing shell. A thin line through the original bushing shell is enough to relieve the tension, which will allow you to remove the shell more easily.
Cut a thin line through the OE shell, making sure not to cut the housing.
Push out the Sleeve
Once you have cut a thin line all the way through the outer shell, this should relieve most of the tension and friction that is keeping the shell in there. From here you can use something as simple as a hammer and punch to pop out the sleeve. We opted for a homemade bushing puller. Here are the pieces we used to build our homemade puller:
- a threaded rod
- a few washers
- piece of metal pipe
- two nuts
- two wrenches
Find a washer that is the same diameter as the outer shell. Then find a piece of pipe or large socket large enough to let you push the old shell into it. Thread one nut on each side of the rod until it reaches your washers. Tighten everything up until there is tension in the assembly, and then center your washers to make sure there is even pressure against the shell on all sides.
Check out this diagram for a detailed look at how our puller works:
You can make a homemade bushing puller with a rod, a pipe and a few washers and nuts.
Use one wrench to hold one nut in place, and use your second wrench to tighten the opposite nut. As you tighten the nut, your washer will press against the bushing sleeve while the metal tube presses against the outer housing on the other side. Keep torquing your wrench until the washer pushes the outer bushing sleeve into your metal tube.
Once the sleeve pops into the metal pipe, just pull it out of the housing.
Clean the Housing of Sharp Edges
Now you have completely removed your old bushing from your arm! Before you install your replacement bushings its a good idea to sand and polish the inner diameter to get rid of any sharp edges and clean up any corrosion that could damage your bushing as its being installed.
Removing any sharp edges will protect your new bushing from potential damage.
Now that you have a nice clean housing, check out our follow up article showing How to install a bushing without a press.