I just called Calmini to verify the idler arm bolt size... Someone else answered my call, but as soon as he heard that I'm having a "clunk" problem, he started asking me a shipping address.

He says, "You're more than welcome to tighen the bolt, but it will develop the clunking again. So, we are sending you replacement bushings..." :rolleyes:

Just in case if anyone's wondering, 28 mm socket fits the idler arm bolt perfectly. Or, yes, 1-1/8" is the next closest.

I was never able to find 28 mm socket or open/close end wrench at Sears. I don't remember where I found my 28 mm socket, but the maker of it is: stanley, not craftsman.

Sears also sells a Metric 1/2" socket strip, runs from 20-28mm skipping 22 and 27. I don't know the part number, I'll have to dig through my toolbox to find it.