What was supposed to be a quick replacement of the upper and lower control arms bolts is turning into a longer project. I have a 1986 GT. The balljoints have previously been replaced and aren't that old. The control arm bushings may be original so I wanted to replace them. I removed all four control arms, the sway bar and the steering rack. There were only a few bolts left that hold the crossmember onto the subframe so I decided to remove the crossmember and treat it to a sand blast and repaint. I left the upper perches on each side of the car (held on with three bolts each) and removed the two bolts on either side that attach the cross member to the perchs. I also removed the two bolts on each side that attach the cross member to the bottom of the frame rails. These two bolts attached vertically around the area of the lower control arm brackets. One of the bolts snapped before it began turning. This one is for the right side and is rearward about where the right coolant tube curves behind the wheel house. I tried drilling and using an "easy" out (bad name), but all I did was wear down the easy out and break a few bolts. I ended up drilling the bolt through the center about the same diameter as the original bolt thinking that I could just drop a bolt down through the hole. Unfortunately, there aren't any access holes in the subframe like I'm used to in "A" body GM cars. Not sure which was I should go here. I could cut a hole in the side of the subframe and drop in another bolt, but I'm unsure of weakening the structure in that area. This is unlikely to be an unusual situation with these cars. What have others done or what do you suggest?
FYI, this is a rust free car ... just had one bolt that was weak.

I had one break off before, I drilled four small holes and cut out the center to make a small box with rounded corners, about an 1-1/4 " to access the capture nut, then with a die grinder, I used a grinding stone, took it right down to the baseplate and added a nut inside the rail. I was able to hold the nut in place with a box end wrench while torquing it from below.

Thanks. That's sort of what I had in mind, but didn't want to cut it up and find out later that there was a better method. I may do something similar to what you described and weld in a plate to close the opening.

I just broke the same bolt in my car.

I'm looking at cutting the frame rail open to remove the nut plate and operate on it on the bench.

Anyone know if this is feasible?

I had to cut the frame rail open and remove the nuts entirely. I broke an easy out off in each. I had to remove them and weld up a new one. When I get home I have pics I will post. Easy enough if you have a welder

MIG welding nuts to the broken shaft of bolts has worked for me everytime I tried (on fiero parts).
I've done it to about 12 broken bolts and after welding I wrench the bolt of with a ratchet using 1 hand. The high heat of welding really helps to break the rusty bonds.

quote Originally posted by ElTee: I had to cut the frame rail open and remove the nuts entirely. I broke an easy out off in each. I had to remove them and weld up a new one. When I get home I have pics I will post. Easy enough if you have a welder

Please post. I'd very much like to see the inside of the frame rail so I know what I'm getting into.

Also, how many layers are the sides of the frame rail? I'd be inclined to cut into the outside of the rail as that's the most convenient place to access, but if the outer face is multi-layer and inner face of the rail is single layer, then it would be less invasive to cut into the inner face.

Thanks!

Heres the link to my old thread.

https://www.fiero.nl/forum/Forum2/HTML/126699.html

The Side of the frame rail is only maybe 1/8th inch of steel and its only one layer. The Bottom of the Frame rail is actually 3 layers. The Capture nut/plate, the bottom of the frame rail, and another piece that is between the cross member and the bottom of the frame rail. I didn't really look at this piece too hard, but it just looked to be some reinforcement.

I didn't snap a picture of it when I had it opened up, but I cut open the frame rail like this. I didn't fully cut the patch off, I left it connected and bent it down to access. If I had it to do again, I would probably cut it all the way, and just weld a larger patch to cover the hole.


This is a side picture of the actual plate that the capture nuts are cast into. I've actually got it upside down, the the two capture nuts face UP inside the frame rail. On the left, at the top you can see the end of the bolt stick out where it sheared off. This plate is Welded to the bottom of the frame rail. I couldnt find a good way to get the extractors out with out removing it, so broke the welds (which you can see on the top about an inch inside of the capture nuts. those little nubbins are where it was welded.) I did a good bit of damage to the bottom of the frame rail getting these out, but was able to take a small hammer and Flatten it out so when I welded the new plate in, it wasn't a big deal.


What I did do, was take my grinder to it, and grind off the top of the bolt. After it was flush, I took my drill and drilled down into the bolt from the top. Once I hit the Extractor, I took a center Punch and knocked the extractor out from the top. I didn't have any luck saving the piece. I could have step drilled the holes bigger and bigger, but they didn't appear to be centered. At this point, it was less effort to just go ahead and make a new plate.


Picture of the new. Bought 2 nuts and an appropriately sized bar from Home depot (they were only grade 8, i'd get stronger ones if you can) I think the bolts are class 10.9? I'd get a matching nut, but I didn't even think about it until I welded the frame shut. If these were the only things holding the crossmember to the frame I would redo it, but they aren't so I wont. Anyway, Cut the bar to the same size as the original using my hand held cutoff tool, laid the original over the new bar, and used a center punch to mark where I needed to drill the holes.


Another picture of the new. Don't judge my welding.


In order to weld this into place, I put the plate into place, and put the bolts in from the top (that is to say, head of the bolt inside the frame rail going through and down out of the lower frame rail.) I Attached the cross member to the opposite side of the car and then lined up the bolts through the holes on the cross member and placed nuts on the bolt to hold the cross member to the car. Tack Welded the plate in place, removed the cross member, then took the bolts out and finished the weld. Just weld the frame closed, prime and paint. It'll be like new.

Thanks!