Is RTAB bushing material selection critical?

[Andre3127]

I'm planning on dropping my subframe soon and replacing all my RTAB/subframe/sway bar link/diff bushings. I'm planning on machining the bushings out of delrin, but I thought about using PVC. It machines quite well, and is significantly cheaper.

So, my question.... is plastic selection critical at all? Is the difference between delrin and PVC worth worrying about? Or is a hard plastic just a hard plastic in instances like this?

[earthwormjim]

PVC is a lot softer than Acetal. Isn't PVC subject to cracking too?
You're already saving a lot by machining your own parts, is the material cost that much higher for something as small as a bushing?

[varg]

Don't use Delrin, it'll probably drive you nuts squeaking.

UHMWPE is a suitable material, Condor makes bushings out of that.

[Andre3127]

PVC is a lot softer than Acetal. Isn't PVC subject to cracking too?
You're already saving a lot by machining your own parts, is the material cost that much higher for something as small as a bushing?

I've machined both. PVC is harder.

[AndrewBird]

I've machined both. PVC is harder.

Looking at the specs pulled from the web, PVC has a durometer around 80D, while delrin (acetal) is around Rockwell M90, so delrin is a bit harder than PVC.

http://www.pactumax.com/downloads/Plastic%20Machine%20guide/Plastic_hardness_guide.pdf

At any rate, I would not use either for a bushing. I'd stick with polyurethane. UHMW is also used, but it doesn't work as well in high load applications because of its tendency to dent and not rebound completely.

[wworm]

PVC shatters under stress, wouldnt use it in any bushing application ever, especially considering that it has zero lubricating properties so itll be loud as fuck and then explode and everything will go to shit.

Stick with known materials, theres a reason everyone uses poly and delrin

[earthwormjim]

I've machined both. PVC is harder.

It's definitely not harder. It also has hardly any fatigue life, and cracks or shatters when stressed.