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Has anyone got any thoughts on replacing the rear suspension bushes? One of mine has too much play in it...

I have some "prototypes" I made that I will be using in the fall. They are solid delrin with a steel bush in the corner.Bear in mind that 411/412 rear trailing arm bushings are not like normal standard bushings. As originally designed, they arean active part of the suspension. They are designed so that the steel bush itself is "pinched" between the side walls of the trailing arm mount when you tighten the bolt. This means that the bonded rubber part will "twist" when the supsension moves. What usually destroys them....other than just age....is when someone (usually the dolt at an alignment shop)....tightens the pinch bolts when the car is off the gorund. When the car gets on the ground again....the rubber over rotates and starts to shred.

This by the way...when the rear trailing arm bushings get shredded...can lend abot 1/4" more sag to the rear and too much camber.

A couple years back,Audi made control arm bushings for teh S-4....from Delrin. They noted that as long as you use materials that do not actovely transmit a lot of vibration....and the suspension is calibrated for less flexability....it works fine and teh bushings do not deflect and change suspension angles in cornering.
So....I am going the same route.
Any shop with a lathe can turn bushings out of delrin. Get some steel bushing stock for the center. Make it thick wall. Then...be sure to have a recess cut in each end for a metal thrust washer. This way ....unlike teh stock bushing....and more like the front control arm bushing....the whole assembly can turn. Ray

Glass filled delrin sleaves with steel crush tubes is what I'm doing too. I removed the old bushings and spring sleaves, machined flanged glass-filled delrin sleaves to a press fit with the control arm, then machined steel crush tubes to a slip fit with the sleaves so the arm will pivot on the delrin sleave about the crush tube.

most of the story is in this thread http://www.shoptalkforums.com/viewtopic.php?t=99437

I've yet to install, but like ray says, this approach is used in other cars as a performance upgrade.

Ray, why do you want the whole assemby to pivot in the arm? Did you make a new liner for the arm for the delrin sleaves to rotate in? do your sleaves have flanges?

Yes, the way I made mine is a tube shaped delrin bushing that presses into the arm from one end. The flange is somewhere in the neighborhood of 4-5mm thick. On the other end I put a delrin spacer...also about 4-5mm thick. This is instead of making two short flanged bushings for each pivot point....like you see on the vanagon. I did not want to have a seam on the inside of the round bore in the trailing arm by having a split bushing.
I am going to press the flanged bushings into the arms from the outside in....in other words......the flange parts that is one peice with the delrin tube....is on the outside side of each arm. The added thrust washer is on the inside side of each arm. I had a 2mm recess for a bronze thrust washer turned in the face of both the outer attached flanges and into face of the delrin spacers. this is so when they turn against the steel mounting point they do wear on it. Also.....so the twisting movement will not try to turn the delrin bushing in its bore.

Bill...your method should work well. In the factory bushings the steel tube pivots around the bolt. This keeps the wear down and makes sure that you have materials of the same hardness against each other. The reason I did not want the arm to pivot around the plastic itself is because of the potential for cracking of the delrin due to shock because of the need to have tolerance between the bushing and the inner tube bushing.

But the drawback of doing it my way....is that once you press in the delrin part...you need to slowly clearance either the steel bushing or the inner bore in the delrin before pressing in the iner metal tube bush to keep from cracking the delrin.
This would also work very well on the front control arm bushings. If you need a drawing of how I made mine, let me know. Ray

I could just as easily had a straight tubular bushing that pressed in from either end and then simply add a delrin or bronze thrust plate at each end. That woudl work well also.

Thanks for the helpful replies guys, it is much appreciated!

I took the trailing arm off at the weekend, unfortunately I've discovered it's rotten It seems to have rusted from the inside out as superficially it looked fine... I see func412 had a similar problem with his http://www.shoptalkforums.com/viewtopic.php?t=110187. Glad I've found this out now rather than when the arm is under load, in a tight bend...

Now I need to find another arm.

This problem happens when the enamel or coating starts to wear off in certain points, especially right up near the bushings . There were a couple of small openings that were generally plugged. But if they open up, water can get inside. Ray