Datsun Roadster Forum-311s.org

Slackline wrote: Fri Oct 23, 2020 10:36 pm It is completely flat on the back with just the hole through the (off)center

The clutch slave dust cover would be hollow, thin walled and stretchable. I don't believe that is a stock part but to me, it looks like an exhaust hanger isolator, something that isolates the exhaust system from the frame to reduce any mechanical noise. A bolt would go through the hole. The oblong hole suggest something heavy hanging on it...maybe it came from another car and the PO jammed it in between two things to stop a rattle...? Just guessing...

If it is a solid rubber biscuit, it looks like an aftermarket shock bushing. If hollow, probably some kind of aftermarket suspension boot/seal. Agree looks non-roadster//

I could not see where it came from. The only fresh looking work was the clutch master/slave and some exhaust pipe work. Probably was just sitting on the frame and fell off.

I believe I have it I was removing my exhaust this evening and found a rubber vibration isolator that looks just like it. Just behind the clutch housing is an exhaust hanger. There is a rubber spacer between the pipe clamp and hanger that looks just like your picture. I believe you will find you have a broken bolt on that hanger and the isolator fell out. I hope for your sake I am correct.

Thanks.

I'll check tomorrow.

Looks like Bonnet rubber \, should be one each side !