sr5guy |
11-02-2009 10:31 PM |
Forward Front Control Arm Bushing Discussion
I've noticed that the front control arm bushings are quite soft or even cracked and broken on most Legends that come through my shop. If you have an automatic the softness is very evident. Put the car in gear with both front wheels off the ground and power brake it in reverse and then in forward. Watch the control arms jump back and forth almost a 1/2". The soft bushings make the legend more prone to wheel hop and suspension vibration "amplification". I imagine they also take some of the bite out of off the line acceleration as the rubber is absorbing some of the take off energy, similar to soft motor mounts. I believe harder control arm bushings would have an effect similar to an engine damper on acceleration.
I really see a need for these bushings to be made of a harder durometer rubber. I don't think a polyurethane bushing would do well with the Legends wishbone suspension setup because the control arm bushings need to be "set" in order for proper suspension dynamics. In other words, the bushing has to have some "spring" to it so that it always returns to ride height by itself. The inner sleeve (where control arm goes through) needs to be directly connected through whatever medium, rubber or poly, to the outer sleeve. This "spring" is what coaxes your steering wheel to straighten out by itself when you let go of the wheel after a turn. Most polyurethane bushing setups are designed so that the inside sleeve can move freely within the outer sleeve with a special lubricant that must be periodically replaced = almost no spring at all. This probably works great on McPherson strut suspensions, but not the Legend's wishbone.
The steel sleeved front control arm bushings are pressed into the front subframe brackets. Real pieces of engineering those brackets are, if you have the opportunity to look at one you will be amazed at the intricacy of it. It ties the front motor mounts, front subframe crossmember, side subframe stiffener, control arm and uni body all together in one neat little cast aluminum assembly. Needless to say, in Honda's great wisdom the only way to replace or repair this bushing is to buy a new bracket. The brackets are $500.00 each. I should mention that the type II control front control arm bushings are more firm than the type I, but not significantly. The brackets have different part numbers from a 95 LS Sedan to a 95 GS sedan. The rearward front control arm bushings remained unchanged.
So does anyone have any idea how we can make some replacements? Can they be gutted and filled with rubber? Who makes rubber casting stuff? Some type of polyurethane? Are there bushings already made for other cars that can be made to fit? Lets talk I think this would be a great upgrade for the Legend's suspension.
-Matt
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