Bushings......

[hoganalley]

I've been getting some squeaks after replacing passenger side tie rod on the weekend. I know my arms are good because there's no play when I do the 9/3 12/6 check. I'm going to re-tighten all my bolts when I get a chance--that should fix it.

My question is.....people use urethane to fill their cracked bushings and thing for tranny mounts, motor mounts, diff mounts, or whatever to stabilize them. Has anyone tried using urethane on the control arm bushings to see if it would help make them more solid?

You can order powerflex bushings and replace them all, but that's expensive and a pain. What if you just filled the gaps and created a solid bushing?

Any thoughts?

[onemoremile]

Has anyone tried using urethane on the control arm bushings to see if it would help make them more solid?

It would make them a different type of bushing entirely.

The stock bushings have a metal sleeve surrounded by rubber and this is what locates and mounts one end of an arm. When the bolt is tightened the sleeve is locked in place leaving the rubber bushing to provide the necessary compliance. This gives the car a nice ride with a unique muted feeling but also explains why these control arms wear out so often and why they have to be installed in certain positions.

Replacing them with urethane bushings would allow them to freely spin about the axis of the bolt. This may or may not be a better solution but I like it better. It allows the dampers more control, keeps the tires planted better under stress, and each bushing can be changed without too much trouble. I'd rather pull and arm and replace a bushing than end up throwing a whole arm away.

[hoganalley]

The stock bushings have a metal sleeve surrounded by rubber and this is what locates and mounts one end of an arm. When the bolt is tightened the sleeve is locked in place leaving the rubber bushing to provide the necessary compliance. This gives the car a nice ride with a unique muted feeling but also explains why these control arms wear out so often and why they have to be installed in certain positions.

I agree totally and understand, but buying all the powerflex bushings is $400+. If we filled the stock rubber with, say a Shore 80A urethane, would it not stiffen the bushing and create somewhat of a compromise between stock and powerflex?

[onemoremile]

It might help for a while but I doubt it would last.

[hoganalley]

so I can try it, it might not last, but if we're replacing these things every two years anyways.....what difference does it make? If it took the abuse better and we got another year or so out of it, it would be worth it. I just don't know how it will feel. I'm sure your roads are as bad as ours, so keeping something close to stock ride would be nice but not totally necessary.

It would be interesting to try. How did the fill do on the mounts you did?

[onemoremile]

The only one I filled was the driver's side trans mount. I don't know if it made it any better but it definitely didn't get any worse.

I also replaced the rubber rear lower shock mounts with Energy poly bushings and aluminum sleeves. This is what could potentially be done to the control arms.

[hoganalley]

http://www.audizine.com/forum/showthread.php?t=232474

if this idea works well, like it seems to have done on previous attempts, then it would stand to reason it should have a beneficial effect no matter what bushing you use it on. Unless it only helps for stationary bushings....meaning ones that don't rotate. Are Energy Bushings expensive? Did you notice a change or any added noise?

[onemoremile]

Energy Bushings are much cheaper than PowerFlex.

No added noise but I replaced a pretty hard rubber bushing too.

Since the control arm bushings are torqued under load the added material may not stay adhered for long.

[hoganalley]

hmmm......interesting.

Energy doesn't have a listing for Audi on their website.....what are the sizes? or do they have it but not listed on their website......

[onemoremile]

You have to measure the old bushings and then find one of their universal ones that fit.

[hoganalley]

I don't know when I can get around to it, but maybe I'll give it a shot anyways and see what happens. Worse case scenario is it doesn't work and then we'll know for sure!