Rear suspension bolts stripped from factory?

[etdigitalis]

I decided to tackle a strut/spring install this weekend and everything was going fine... until I got to the rear passenger side. Since I was installing lowering springs, I was also installing a camber kit. And as you know, in the rear that requires replacing the OEM upper arm w/ an adjustable one. Well, the drivers side went fine... but when I got to the passenger side rear, I found that the two bolts that hold the upper arm to the chassis weren't coming out so easy. Thinking that they may be binding against the upper arms mounting plate, I put them back in attempted to back them all way out. Well, they came out, but the threads on one were visibly jacked. My first thought was "OMFG, I'm totally screwed!" but then I thought that maybe I could pass a tap/die over them and all would be good. Well, the bolts are a 12mm x 1.25mm pattern and wouldn't you know it? Just about every set this side of the Appalacians decidedly skips right over that size. To make a long story short, I ended up using a 1/2" x 20 standard tap/die to fix it... but it makes no sense to me. I'm the first one to touch those bolts outside of the factory and they were damaged? Could this have been done at the factory? Or perhaps the heat from my exhaust (which is about 2" away) has caused some unwanted thermal expansion? I dunno... has anyone else had a similar problem? EtDiGiTaLiS.

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[flotsamm]

First I've read of it being screwed up by the factory... but I guess it could happen. Doubt though that it was from your exhaust.

[Boilermaker1]

Joe Schmo in Ohio doesn't install the bolts by hand. A robot screws them in and its possible that it cross threaded it. As far as not finding a 12x1.25 tap, you should be able to without problem. Thats a standard 12mm fine thread. Craftsman makes a tap in that size for sure and if you looked in mcmaster carr I bet you could find several of them.

[etdigitalis]

Originally Posted by Boilermaker1

Joe Schmo in Ohio doesn't install the bolts by hand. A robot screws them in and its possible that it cross threaded it. As far as not finding a 12x1.25 tap, you should be able to without problem. Thats a standard 12mm fine thread. Craftsman makes a tap in that size for sure and if you looked in mcmaster carr I bet you could find several of them.

I'm leaning towards "the robot theory" myself. I guess a crossed thread is a tight thread

As far as Craftsman making a 12x1.25mm tap/die. If they do, they don't sell it in stores or their catalog (pg. 68). It's possible that Sears.com does, but their item descriptions were too vague to be of service.

You're right about McMaster Carr... that place is awesome. I went to their site to look up the part and sure enough they had it... with a plethra of ordering options as well! My problem was that my car was on a frame hoist at the local auto skills shop and I needed to get it out of there. I couldn't exactly move it with the rear suspension dismantled. So, I tapped it out with a 1/2x20, torqued it down and went to get an alignment.

On the drive over there my steering wheel was off center, but afterwards it's right on and my car handles like a dream!

EtDiGiTaLiS.