Vic, I had to go back to the original picture file to really see the detail on the 'new' surface. It's a clean break. The surface has all the rough and sharp surface grain texture you get from breaking aluminum. There are no 'wipe' type lines or smears that you would have after putting a steel pry bar against the softer aluminum surface.

And you are right about PPIs not catching everything. That being said, Jeff at Black Forest was rather proud of how detailed his inspections are. He gave me a three page check list and over twenty additional comments in the margins. But, I am in a lousy position here. If Jim Becker says he did not do it, there is not much I can do to prove he did. But, but, I am getting ahead of myself. Maybe the previous owner will say he had that problem. We will see.

John H

 

John,
The break sure looks fresh - especially considering the miles you've already put on the car (and the conditions you drove through).

I would be extremely leery of a cast aluminum suspension member in this condition. Frankly, I would have a tough time driving my car briskly if I knew of such a deficiency. You may wish to consider sourcing a used suspension part to replace this. Those pivot points undergo a ton of stress when the car gets well-exercised.

Andreas

 

fwiw: may want to check out http://911pcar.com for some used arms. (no aff'l etc.) pretty damn cheap... maybe even consider doing a suspension upgrade while they're in there...flip this into somthin' positive.
best

 

That eccentric bolt is secured in place when correctly torqued by the clamping force applied to all the mating faces ( fastener under tension) - not by lateral pressure applied to the eccentric stops: to imply the latter suggests that the bolt is allowed to migrate within the adjustment slot and apply varying pressure against the stops. That is unlikely ....
The break does look fresh: were it a preexisting crack that had just 'let-go', there would be a greyish cast to the previously exposed surface. Most alignment guys use two wrenches on such bolts - one to counterhold the eccentric end while the locknut is released. Then the other end is turned to apply the adjustment. In the realm of possibilities, if an air wrench came on to the locknut full force without a counterhold, the eccentric could release with considerable speed .... and smack its stop: that is just speculation, for there are numerous ways the part could have failed.
That part is not so easily replaced, for it is the vertical carrier of .... well, everything on that side. This shot is of a C4S rear. I do not know if it is identical to the C2 rear, nor which of the control arms is in play; however, it may give a better idea of the set-up.

 

Here is a cut from PET that shows the eccentric washer (#21) location within the suspension frame. Left side is shown, the right side is the damaged side. The eccentric washer fastens to part #2, the side panel. It's the side panel that I would have to replace. As Garth says, the whole rear suspension will have to come apart. And that part has to cost a pretty penny. I suspect this is why Jim Becker was reluctant to talk about it.

John H

 

That damage will be almost imposible to do during alignment, something hit that part hard, if you need used or new susp. parts you can pm me I have plenty., cheers, Sonny.

 

Well, armed with my pictures and fortified with all the help from this board, I went over and talked with Jim Becker about this problem. Jim's thinking is that the eccentric cam does no actual holding of position, that the bolt does all the holding. Jim did not think the break was an 'unsafe' condition. Jim did volunteer to repair the break at no charge. The repair will heli-arc weld in a replacement piece that will include a cam stop. So, I think we have an amicable settlement.

Thanks for all the help. This board is a great resource.

John H.

 

Sounds reasonable to me re. earlier comments on the mechanism of fastner attachment. Good luck.