Sway bar bracket bolts stripped

[critter]

Here's a what would you do question for the group.

I made great progress on the suspension this morning. The high today is only supposed to be 95 instead of the 105 we've been seeing so it felt almost like fall outside to me.



However...

Imagine my surprise as I was attempting to torque down the first sway bar bracket to frame bolt to the 25 lb. ft. the service manual calls for and that bolt stripped right out. When it did the other bolt decided it wasn't happy being in its wallowed out hole either and that 1.25 inch sway bar developed a sudden magnetic attraction to my head. Luckily it didn't hit any vital organs and I'm sure this knot will got down in a week or two.

I went to the other side and, sure enough, that metal is about stripped out as well. With the bar removed I stuck a bolt in each hole and tried to pull to 25 lb. ft. The bolts just spin. So they all need repair.

I see 2 options. I weld the holes in the frame, re-drill and tap or I can weld nuts to the bottom of the frame. The latter would certainly be an easier fix. What would you do?

[ErikLS2]

If you just weld those holes up drilling and tapping them will be very difficult as it is much harder than the metal the frame is made of.

Since you can weld on the frame it seems you have several options. A flush mount rivet nut is a possibility but it should be somehow tacked in place with a welder if you can get to the backside of it. A stronger type of heli-coil called a Timesert or Keen-Sert would work well.

Another possibility is to weld a nut (or 2 if both are stripped) to a flat piece of steel. You'll then place this piece of steel inside the frame and plug weld it to the frame through 1/2" or so holes you drill on either side of the bolt holes. You can then grind those welds flat if needed so you have a flat surface to bolt the sway bar bracket to.

If you can't get the steel strip with the nuts on it in place through the end of the frame, then you can just drill the bolt hole opening in the frame large enough to slip the steel strip up into the frame, hold it in place with something and weld it in place.

The only other thing I can think of is a threaded insert like is used on the end of control arms and can be purchased already made. Problem is getting it welded in place so the surface is smooth. I'm sure you can't get to the backside of it inside the frame rail to weld it.

[67 455 Bird ragtop]

I had a similar thing happen a while back. I used a T nut that is normally used in wood. I just snipped off the barbs that hold it in the wood and welded it to the frame. Cleaned it up so the bracket would mount smoothly. Seems to have worked ok. Just a thought.

[Roadbuster]

Here's a what would you do question for the group.

Imagine my surprise as I was attempting to torque down the first sway bar bracket to frame bolt to the 25 lb. ft. the service manual calls for and that bolt stripped right out. When it did the other bolt decided it wasn't happy being in its wallowed out hole either and that 1.25 inch sway bar developed a sudden magnetic attraction to my head. Luckily it didn't hit any vital organs and I'm sure this knot will got down in a week or two.

I went to the other side and, sure enough, that metal is about stripped out as well. With the bar removed I stuck a bolt in each hole and tried to pull to 25 lb. ft. The bolts just spin. So they all need repair.

I see 2 options. I weld the holes in the frame, re-drill and tap or I can weld nuts to the bottom of the frame. The latter would certainly be an easier fix. What would you do?

If you just weld those holes up drilling and tapping them will be very difficult as it is much harder than the metal the frame is made of.

Since you can weld on the frame it seems you have several options. A flush mount rivet nut is a possibility but it should be somehow tacked in place with a welder if you can get to the backside of it. A stronger type of heli-coil called a Timesert or Keen-Sert would work well.

Another possibility is to weld a nut (or 2 if both are stripped) to a flat piece of steel. You'll then place this piece of steel inside the frame and plug weld it to the frame through 1/2" or so holes you drill on either side of the bolt holes. You can then grind those welds flat if needed so you have a flat surface to bolt the sway bar bracket to.

If you can't get the steel strip with the nuts on it in place through the end of the frame, then you can just drill the bolt hole opening in the frame large enough to slip the steel strip up into the frame, hold it in place with something and weld it in place.

The only other thing I can think of is a threaded insert like is used on the end of control arms and can be purchased already made. Problem is getting it welded in place so the surface is smooth. I'm sure you can't get to the backside of it inside the frame rail to weld it.

You cannot use the bolts to compress the factory style bushings. You have to compress them with a jack and then put in the bolts. Larger sway bars are usually too wide for the stock hole spacing and the bolts end up cross-threaded which makes the problem worse.

I think the problem here is the factory did not design the sway bar mounts for the loads that our modified cars can put on them.

I am working this issue myself. Tried the plate with nuts welded to it to get in inside the frame and that did not work. The frame is a messy place inside and it is a pain to get it to line up. If you have an A-body the steering box is in the way.

Somebody here welded rod to the top of a bolt to make a T. This was then put up in the frame though an access hole and the brackets were held on with nuts. This is what I plan to do next.

Another idea is to weld a plate to the bottom of the chassis with tapped holes in it. This would move the sway bar down a tad unless you cut out the frame to accommodate it. For this I was thinking a 1/2 inch plate tapped with holes for 3/8" bolts, then machined around the edge to give a lip. cut hole in frame and insert so that it sits on the lip. Weld it in and the brackets will sit flush.

The last idea is to use a three piece sway bar and run it through the frame. This requires the most work and is just an idea.

Sorry that the post is so long. Hope this helps

[critter]

Well, for now, I've elected to try another route. I'm going to drill it for the next bigger size bolt and re-tap it. If that pulls out after some spirited driving I might be doing the T bolt idea. That seems to make sense, spreading the load.

[MarkM66]

Well, for now, I've elected to try another route. I'm going to drill it for the next bigger size bolt and re-tap it. If that pulls out after some spirited driving I might be doing the T bolt idea. That seems to make sense, spreading the load.

That's what I'd do, should work fine.

[modular93fox]

Man, this it took forever to find this picture. If you used your sway bar clamp bracket as a template, and made something like GMracer did for his trans mount, it could work out real easy for you... here are some pictures of his build thread:



then you could open up the factory holes in the subframe to accomidate the bracket in the first picture:


and then weld it, then drink a beer.. or the other way around..


clint

[critter]

I really had considered something along these lines. Like I said, if it pulls out again I'll be headed that direction. Some things can be improved on. 1974 was a long time ago.

[Roadbuster]

I really had considered something along these lines. Like I said, if it pulls out again I'll be headed that direction. Some things can be improved on. 1974 was a long time ago.

Let me know what you come up with. I stripped out the 1/4-20 and went up to a 5/16 bolt. Pulled one of those out at the RTTC event.

Man, this it took forever to find this picture. If you used your sway bar clamp bracket as a template, and made something like GMracer did for his trans mount, it could work out real easy for you... here are some pictures of his build thread:

clint

Thanks for finding that clint. I like this idea! Looks like that might be my next try.

[David Pozzi]

GM made the sway bar bolt holes by swaging metal into the frame, this gives more thickness so you have more than 1 thread holding. If you drill out to the next size, the metal will be very thin. A nutsert will work, or if you do the plate with nuts it's better to put the nuts down against the frame, not the plate. The frame isn't level inside, there is usually a notch that is used by the factory to prevent the frame halves from overlapping too far, this protrudes into the frame and will not allow the plate to sit flat.

1st gen Camaro Subframe is upside down in photo, nearest hole is not a sway bar hole, next hole is the forward sway bar hole, then you see the "bump" which prevents the frame halves from overlapping when assembled for welding. You can barely see the rear hole.
David

[Samckitt]

I welded a couple of these inside the frame. Drilled a hole next to the original hole to weld through to the tab on the nut. Was kindof a pain in the rear.

[LeighP]

Rivnuts (nutserts) fitted int othe frame then tacked into position to prevent rotation....worked for my 71 project's bar. I'll see how it works when the car is on the street.

[critter]

Well, drilling and tapping did let me pull torque on it. David says it's thin so it might pull out when I get out and start playing. I'll keep an eye on it. Lots of good suggestions here. Thanks, guys.

[kochevy67]

X2 on the nutserts.

[Skip Fix]

I thought the factory used nutserts in the later 70s/early 80s second gen front sway bar mounts.

[critter]

Skip, mine is a 74 and didn't. Maybe in the later cars.

[6'9"Witha69]

I put nuts on the bolts. Seriously, used a shallow socket on a breaker bar with some rubber gaskets fillin the backside of the socket keeping the bolt pushed fwd but allowing the bolt to come through. Chucked up the bolts in a lathe to remove the first 2 threads then pitched the 3rd thread for the best blind threading possible.

[Skip Fix]

What about drilling out and adding nutserts?

[critter]

Nick, you and several others said do that. How did you get inside the frame? From the front? The access holes on the side are not big enough that I can tell.

Skip, I heard from a ton of folks who did what you say, nutserts and welding them on for additional strength.

[6'9"Witha69]

Nick, you and several others said do that. How did you get inside the frame? From the front? The access holes on the side are not big enough that I can tell.

Skip, I heard from a ton of folks who did what you say, nutserts and welding them on for additional strength.

Yes, from the front, hence the need for the long breaker bar.

The nutserts work well, never used them for a sway bar though.