silicone boy Posted May 30, 2002 Share Posted May 30, 2002 Tonite, I was doing one of the the dirtiest and least pleasant jobs in all of auto mechanics, replacing suspension bushings (in this case with polyurethane ones). As I was trying to take off these ten million year old pieces of rubber, two thoughts came to mind: 1)Why am I doing this... does it really make that much difference in handling, 2) Those heim jointed rear suspension units of Arizona Z's are starting to look a lot cheaper right now. I used various combinations of penetrating agents, C-clamps, a shop press, all with varying success. I have nearly every tool imaginable for suspension work since I've been more of a suspension person rather than an engine person over the years. I soon rediscovered one of the oldest tools known to man: fire . I don't mean heat the bushings so they can be pressed out. I talking about taking that blowtorch to them and burning them to a crisp (actually, they burn on their own after a while). Never underestimate the utility of a good flame. It sure smells (not all burnt rubber smells good) but it works. Just thought I'd save you all some time if you decide to undertake this chore. Next time, I'll get a fully adjustable, heim jointed number (if the racing class allows). Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted May 30, 2002 Share Posted May 30, 2002 I don't mean to burst your bubble, but many of us do that. Fire (just showing some flames, I'm not mad) kind of goes hand in hand with replacing those old rubber bushings. It's the easiest way to get those suckers out of there, even though it may not be the most pleasant smelling. Good tip though, silicone boy. !M! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 30, 2002 Share Posted May 30, 2002 Heat scares me. 1200 degrees farenheit will soften steel to it's softest point or take all the temper out. 400 t0 500 degrees softens knife steel to a durable cutting edge that is hard to crack or break. I considered fire but got afraid and did it the old fashioned way.. labor intensive. I doubt if the burning will damage or soften the steel that much but....... do not mean to rain on the parade but I am cautious with a car that will go to 100 mph in about 13 seconds. Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted May 30, 2002 Share Posted May 30, 2002 When I did my bushings, the metal didn't get red hot. It was just warm to the touch after about 2 minutes of cooling off after burning the bushings out. The hottest part of the flame (with a torch) is centered on the bushing itself, not the surounding metal. I would say, maybe 300 degrees is all the surounding metal is subjected to. Not to bad. Think about how hot a caliper bracket gets after some track time, haven't heard any horror stories with those. Certain metals react differently to heat. Think about what happens when you weld certain metals together, that is very hot! I can't remember much from physics back in high school, but today I would say that heat is a metals friend if used correctly and on the right metals. If any of my thinking is incorrect, someone please fill my cranium with the right info. !M! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 30, 2002 Share Posted May 30, 2002 Just do not get it red! Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted May 30, 2002 Share Posted May 30, 2002 Good advice Tee Zee . !M! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 30, 2002 Share Posted May 30, 2002 UUmmmmmmmmmmmmmm Relax big fellow, Fire is our friend *... Agreed, aim the heat at the rubber and move around slightly unless you plan to case harden them (haha, unlikely) theres no need to go cherry red on the surrounding metal. Good point though, heat does have an effect on metal, specially like Aircraft alloy aluminum which can get pretty structurally weak if submitted to high temps. The heim adjustable Az Z car arms don't look cheap to me ever... Regards, Lone * See Young Frankenstein for this visual, its one of my favorite movies.. Quote Link to comment Share on other sites More sharing options...
Guest tom sixbey Posted May 30, 2002 Share Posted May 30, 2002 just a note - ssume you guys are talking about removing those awful moustache bar bushings!!! - without fire, it took me 5 hours to remove those 2 bushings alone, and prepare the moustache bar for the new ones.. Fire is definately a quick answer in this case, but dont over do it! Quote Link to comment Share on other sites More sharing options...
Guest Fast Frog Posted May 30, 2002 Share Posted May 30, 2002 Hmmm: I guess fire does work. I don't have a torch so I changed out 2 sets of mustache bar bushings with a big screw driver that I ground real sharp and hit it with a hammer. Took me about 1/2 hr per bushing. They cleaned up pretty good and I just popped in the new bushings. Quote Link to comment Share on other sites More sharing options...
Dan Juday Posted May 31, 2002 Share Posted May 31, 2002 Boy, here's an old subject again. But hey, if your doing it for the first time it's new to you. And guess what, I'll be doing it for the first time myself this weekend. I picked up an R200 bar at the JY for my swap and the bushings are toast. I'm going to use the torch on them. I have an infrared thermometer so I'll give you guys the difinative answer on how hot the metal gets. Now, if I remember from earlier theads on this subject, I'm suppost to leave the metal sleave in the bar if I'm replacing with urethane, right? Straighten me out on this guys. Quote Link to comment Share on other sites More sharing options...
pparaska Posted May 31, 2002 Share Posted May 31, 2002 Yes, leave the metal sleeves in the M-bar. That's the only place on the entire Z that you must leave them in when putting in the garden-variety polyurethane bushings. You don't need to burn all the rubber out. If you heat (slowly) the M-bar "curl" around the bushing until the rubber starts to smoke and smolder, you can pull the center sleeve and rubber out with vise-grips, pliers, etc. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 31, 2002 Share Posted May 31, 2002 Will be very interested in the reading on that infrared thermometer Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted May 31, 2002 Share Posted May 31, 2002 Man, Young Frankenstien is a classic!!! It is a must see for anyone that has not seen it! So many good lines in that movie. !M! Quote Link to comment Share on other sites More sharing options...
dsommer Posted June 3, 2002 Share Posted June 3, 2002 I did the fire route on mine and it worked like a champ. After the old bushing was out a got a small cupped wire brush (the kind you put on an electric drill) and ran it inside the sleeve where the new bushing goes. It cleaned it up perfectly (no left over rubber junk) David Quote Link to comment Share on other sites More sharing options...
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