Frame threads stripped, Sway bar bracket bolt , 69' Goat ..
 

hi, friends,

I thought I'd saved a link to the fix that most guys are using here but apparently not. could I get a refresh please? and what size am I looking for?

thanks,
mike
MA

I have the exact same condition and haven't gotten around to repairing it properly.
Subscribed.

hi greg,

https://www.rivetsonline.com/rivet-n...readed-inserts
just got to figure out size needed

best,
mike

Riv-nuts are what I used/installed. Very pleased and would recommend doing so again. Either plug weld and re-drill or what I recommend above.

Tim john---

Riv-nuts are a great idea. They used them a few times on a job I had but I've never seen them in a store. Where can you buy them?

Oops... I guess you already answered the question.

Harbor freight sells them and the riv nut setting tool.


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Didn't know that. Thanks. I found a video on how to set them using a bolt correct for the threads and a slightly larger nut under the head. Pretty simple technique.

I have an Amazon tool for Rivnuts but on the larger sizes like 5/16" and above I often use the bolt method ... often you can't get the tool in a good position .. and that is very necessary for the large thread sizes.

This is also how I fixed the stripped thread in the same location as the OP.

Stripping these out is common I think because evidently no one actually sells the right size rubber bushing. I still had to cut down the bushing at the base unless I wanted to try using like 100 ft/lbs to bring the bracket into the correct location.

And I guess that regarding size, you just fit it to the hole?

Odds are the hole will have to be drilled out larger. I'm guessing those bolts are probably a coarse thread 5/16 or 3/8 ... the OD of the Rivnut is going to be larger than that, and you'll want to pick the right "grip range" for the thickness of the metal in that location.

Another option would be just tapping the hole out to the next size larger and using a new bolt. But .. there isn't a lot of meat there to tap, although evidently the factory thought there was enough.

I'm expecting to have to enlarge it just a bit even if just to get a good, clean and round hole. I'll have to get down there and take a look. Honestly, I'd forgotten about it until Mike brought it up with this thread but it's not a good situation and needs to be addressed for sure!
I plan to do all four when I get it figured out.

I know some people will frown on it but on my ‘66 Catalina, when I installed the fat sway bar, I ended up taking a hole saw to the side of the frame so that I could put a wrench inside the frame to hold a nut. Drilled out the stripped holes and used good quality nuts and bolts. Nice and secure. A nice round hole on the frame just looks like it belongs there anyway! Plus it’s lighter now . . . .

X2 on tap a slightly bigger thread if you're not worried about original fasteners. Exactly what I did and it's been holding up for several years with lots of street driving. The bushings are huge and crush down.

You can tap the hole for a bigger bolt, but then it will always be mismatched to the rest of them.

back in teh day when I was a teenager I had a sway bar bolt strip out on a 2nd gen T/A, a friends dad was able to weld a nut on the inside of the frame using the factory holes in the sub frame, worked great for many years of hard use.

Today I would use a rivnut as mentioned above, they are cheap & easy to use, dont need the tool, just a bolt & washer, can see the install steps on youtube.

I buy the rivnuts at fastenal, probably a little better quality that harbor freight.

Amazon also has the nuts and the setting tool:

https://www.amazon.com/s?k=rivnuts&c...f=nb_sb_noss_1

Funny, I was going through some coffee cans yesterday looking for some washers and found about a dozen rib nuts that I didn't even know I had. Have no idea where they came from. Way too small for this application though, unfortunately.

McMaster also has a large selection of them.

On critical applications I'd always attempt to put a couple of tack welds on the back side to prevent them ever spinning if the bolt seized.

And ... when you are choosing your Riv-nut ... look for one with a very thin flange on the surface. Some have pretty thick flanges that will prevent the bracket from seating nicely on the frame.

Good point on having a thin flange, many have a thicker flange that would interfere with the bracket but probably not enough to cause an issue since the rubber/poly bushing is compressed before the bracket touched the frame.

Heres a pic of the fastenal rivnuts or "nutserts" as some call them, they have a very thin flange & serrations to grab the hole when inserted & compressed, also coated with a gold colored finish to prevent corrosion. They were about .50ea when i bought them a couple years ago. 3/8-16 thread to match the original bolts.

I bought these for my 81 T/A that only had threads tapped in the frame in case they strip out.

I have a Fastenal store nearby. I'll stop in and see about those.

Thread-serts and riv-nuts are good, but you have to make sure the hole is the correct size. In some cases, that means you have to buy a fractional drill bit.

Take care drilling the hole too, and don't go back & forth thru the hole, or it will loosen up.

Once you go over about 1/4" size, or if using steel inserts, no way can you use the plyers type of setting tool, has to be the larger setting tool.

I know a lot of people use a plate with nuts welded to them, and fished them into the frame from the front or from the spring pocket.



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Carefully weld the edges of the stripped hole, then re tap.
Alum riv-nuts have their place, a front swaybar mtg hole is not one of them.

bigger than 1/4" or steel rivnuts can be installed without the special tool... they dont use pliers, they use a bolt/nut/washer set up with wrenches that will set a 3/8 steel rivnut without a problem.

The rivnuts i showed from fastenal are not aluminum, they are steel.

Pics of both types of setting tools attached.

You can monkey it with washers/bolt combo, but if you've ever had to remove one that did not set right, you will always use the tool from that point on.


The inserts only compress so far, and if the hole isn't the correct size, they will either be loose, or won't compress enough to conform to the hole.



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That was my original plan of action and still an option. Going to look into the rivnut first.

Im aware of the tools for this, was just stating that they can be installed properly, no monkeying, without the tool and that wrenches not pliers are used for the DIY approach from what Ive seen or watched others do. They even sell a "tool" that mimics the bolt/nut/washer DIY set up. https://www.amazon.com/Rivnut-Insert...a-726518485150

Heres a few vids showing how to do it without the tool for those interested, the riv nut compresses to the thickness of the metal its used on, the drilled hole has to be the right size of the rivnut used but being a tad too large or small wont make it not install right if fully compressed. for the 3/8 rivnuts discussed here, a standard 9/16" drill bit is what most call for.

https://www.youtube.com/watch?v=heLMQYwE1_o

https://www.youtube.com/watch?v=WYvvdwSMNVE

https://www.youtube.com/watch?v=u4huFzeQIgw

I wasn't saying use plyers for a diy approach, I was talking about the tool that has plyer-type handles, like in the pic I posted.

When using steel rivet nuts, when you do the bolt/wrench/nut thing, it can tweak to one side, and can cause it to fail prematurely from not tightening evenly/square against the bulkhead. Ask an airframe mechanic, they will tell you.

Do it however you feel like doing it, but can say for certain using the correct tool makes for the best possible installation.


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The original design was terrible, tapping threads in a relatively thin frame rail was a half baked way to do the sway bar attachment. As many of you have found the first time you try to replace the bushings or upgrade to a bigger sway bar the threads in the frame fail. Of course going to a larger stiffer sway bar increases the the stress and the ability of the one or maybe one and a half threads at best that are tapped in the frame to hold.

When I upgraded both of my ‘64 A-body Pontiacs to the 1-1/4” T/A front sway bar I had the front bumper removed which allowed fairly easy access to the inside of the frame. I was able to place some 17mm hex M10 metric nuts inside the frame and used the factory metric sway bar bolts. Nice and tight installation, those large hex nuts provide plenty of area inside to prevent any kind of pull through and are likely stronger than a Riv-Nut.

The frame rails are pretty straight in front so probably much easier to get those nuts inside on ‘64 - ‘67 A-body cars than on later ones.

Im sure installing these or anything can go wrong, but Ive never seen a rivnut go sideways using the bolt/nut/washer set up, the vids posted & a bunch of others show the rivnuts being compressed nice & square as the bolt is tightened by hand or with a drill.

Just showing a DIY way to do it that doesnt require a ~$40-50 dollar tool for a one time or rare occasion use... if youre an aircraft mechanic or install a bunch of these then a special tool is best.

That's my objection to buying the tool. I may never need it again for the rest of my life.

I use thread-serts/rivet nuts alot. I use them for all my grounds, into the frame and/or panels, ensures the best possible contact. I rarely use sheet metal screws anymore, all are thread-serts/rivet nuts.


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