control arm bushings
#83
#84
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Seriously, though, I think the grease paths will do the trick. I hope to install them this Friday with any luck. Regarding the design, I like the embedded and external washers better than the typical design of a poly bushing for this particular application, but I do wish they were closed on the opposite end as well.
#85
TECH Junkie
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I like the external washer too. It seems to keep the shoulder of the traditional designs from squeaking against the subframe during suspension travel while also securing its position. Our noises seem to be coming more from turning the wheel moreso than from going over bumps. If the inner portion of the bushings had the same design as the outers, with the external washer and flanged shoulder, I think this could be remedied.
#86
If that washer was working as intended, it would be grinding the **** out of your cast aluminum control arms. The reason why real bushings don't have that washer is because the bushing shoulder is designed to act as a sacrificial anode. Polyurethane bushings don't work the same way as rubber bushings, which are soft enough to allow the captured sleeve to torque the rubber.
You don't need a shoulder in those designs because the sleeve isn't free to move. That's both a blessing and a curse--the bushing has no chance of rubbing or squeaking, but it's poor in deflection and applies a nonlinear resistance to rotation, making your effective spring rate progressive even with linear springs installed.
The real, 100% solution would be an upper yoke with flat, wide, exactly perpendicular mounting tabs to support polyurethane bushings. The majority of the squeaking and fitment problems people have are caused by those thin, outward curving tabs that tend to saw the edges off the polyurethane bushings.
You don't need a shoulder in those designs because the sleeve isn't free to move. That's both a blessing and a curse--the bushing has no chance of rubbing or squeaking, but it's poor in deflection and applies a nonlinear resistance to rotation, making your effective spring rate progressive even with linear springs installed.
The real, 100% solution would be an upper yoke with flat, wide, exactly perpendicular mounting tabs to support polyurethane bushings. The majority of the squeaking and fitment problems people have are caused by those thin, outward curving tabs that tend to saw the edges off the polyurethane bushings.
#88
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Um, yeah, I'm going to have to go ahead and disagree with you there. I'm not sure you are aware of the location of the washers/plates. The outer one is not grinding on the arm- it rests against the subframe. The other embedded plate/washer is against the machined face of the arm, but as even you have explained before, the bushing isn't rotating in the arm, so no relative motion, hence no grinding.
#89
Staging Lane
Update:
3 holes and 3 grooves in each
Not bad for an old drill press, harbor freight cross slide vice, and dremel material removal bit. Center hole opened up with a 1/2" 4-flute chamfer tool.
Just need to polish them up a bit and clean them, should have it back together this weekend.
3 holes and 3 grooves in each
Not bad for an old drill press, harbor freight cross slide vice, and dremel material removal bit. Center hole opened up with a 1/2" 4-flute chamfer tool.
Just need to polish them up a bit and clean them, should have it back together this weekend.
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Also worth noting is that the taper of the bushing ID should help with grease direction/retention because they are drafted away from the open end (i.e., the end where you don't want grease to go is a slightly tighter fit than the flanged end- mainly for mold release, I assume, but should help with proper greasing).
#95
Staging Lane
Open on the one end to hopefully feed the thrust face since the bushing has channels already in it. When I was working the arms up and down it felt like most of the noise was coming from the thrust surface. Was just cleaning up the bushings and saw a bunch of check marks on the thrust face, definitely binding. Currently finishing the channels with a nice chamfer. Going to try to get it back together this weekend.
Last edited by TST_brah; 05-27-2017 at 01:05 AM.
#96
Staging Lane
Got the arms back in the other night, greased, torqued, and greased again. Worked the arms up and down and they moved both smoothly and silently. Set the car down a coupe hours ago and no noises. Took it for a drive and it was dead silent, nearly cried. Why didn't I do this a year ago?! Time will tell if it stays quiet or starts making noise again, very happy so far. The new front shocks felt awesome too, didn't flop in the dips and dampened the choppy roads in my test loop much better. Looking forward to replacing the rears now.
#100