Need Advice On Radius Rod Bushings on 1972 240 Z

[Otto Skorzeny]

You guys helped me out yesterday on clutch recommendations so here's another question.

1972 240 Z

I replaced the badly worn radius rod bushings (strut rod) according to the service manual.

The problem is that when torqued to the specified limit (40 ft lbs), the well beyond the edges of the the big washers that hold them in place.

In my experience, rubber bushings normally should be tightened until they just bulge to the edge of the washer or so.

These do have a steel sleeve inside that goes through the frame and (I assume) acts as a seat or stop for the big washers.

Should these bushings be squished out of shape like that? The bushings are made in Japan by Beck-Arnley. The old crappy ones were smushed up tight and the big washers were embedded in them as they had squeezed out around the edges.

What's the straight dope on how tight these should be and what should they look like when properly installed?

Edited September 17, 2013 by Otto Skorzeny

[Captain Obvious]

Yes, that sleeve is in there to act as a stop for the large washers, and yes... Even with that sleeve installed, the bushings deform significantly when the nut is tightened to bottoming. I'm with ya, it's more deformation than what is usually considered "normal", but it's correct.

That's why the bushings you took out look very little like the new ones you're putting in.

[Otto Skorzeny]

Well, I guess I'd better get under there and tighten them up to where they're supposed to be. I was afraid I'd ruin them.

Thanks again for your help. I have some more questions to ask but I'll get to those later.

[Otto Skorzeny]

Yesterday I saw a 1960 Crown Imperial on a rack. Someone had recently installed new torsion bar bushings and I immediately noticed that the big washers that hold the bushings in place had the concave part facing away from the rubber. I think this is incorrect.

The concavity is there to cup the rubber bushing and help hold it in shape. If the manufacturer intended that it be installed with the convex side toward the rubber it seems to me that flat washers would be supplied.

Anyway, it got me thinking about the Z. I installed the big washers with the concave side against the rubber as I have installed all such bushings on various vehicles.

It may seem like a silly question but is this correct?

[Zed Head]

I'm going to guess that the "concavity" is just the result of adding a stiffening ridge to a big flat washer. The ridge keeps the washer from flexing, making it stronger. I don't think that the rubber bushing outer dimensions fit inside the inner cup dimensions of the washer, so there would be no real containment if they were flipped.

Check post #20 in this other thread - http://www.classiczcars.com/forums/suspension-steering-s30/50438-uhm-i-think-thats-supposed-attached.html