Hello All,
Does anyone currently have Polyurethane Bushes fitted to their front tension Rods?
I have a pair of castor adjustable items I was due to fit this week, but when I’ve thought about it, I’m not sure that a poly-bush here is a wise idea.
My concern is that looking at the layout of the front suspension links, the tension rod is required to move around two axes of rotation. It needs to rotate up and down axially as normal, but as the arc of the lower control arm pulls the outboard end of the tension rod inboard and outboard, the bush also needs to allow the rod to rotate laterally also. The OE original rubber bush is compliant enough to allow this without putting a high bending moment in to the tension rod. A spherical bearing would allow the same.
The polyurethane bush is significantly stiffer then the rubber bush and is a step closer towards being a pinned joint with only one axis of rotation. My question is does a Poly-bush have enough compliance to allow suspension travel without putting too much bending stress on the Tension rod.
A quick google search on this subject shows that some owners of other cars (300ZX and S13/14) with a similar setup have had some problems in this area. Has anyone had a bad experience in an MR2? Bent Tension Rod? Tension rod – Control arm bolts shearing, Tension rod weld failure etc??
I am hoping that there are quite a few of you using a polybush here and have had no problems!! Then I can fit the bushes with some confidence that all will be OK. I did consider rose jointed adjustable rods, but they are a lot of cash, and I didn’t fancy every Fore/Aft wheel input being transmitted straight into the chassis with no damping.
Cheers
Dan