Does anybody have an opinion about bolting in my formerly riveted frame cross members? In my cc project, I have to bring over a cross member from the donor truck, and I have to move another. I was planning to bolt them in with nuts and lock washers, but then I started worrying that they might come loose with the frame flexing and twisting. I know the tranny member is bolted in. Anybody's two cents would be appreciated.

 

I wouldnt worry about it . Just bolt them and use lock washers and crank as the tight as you can. and i supose if you thought you had to you could spot weld the nut so it could loosen, but i would say that would be a bit over kill

 

I would use some grade 8 bolts, just as strong as rivets or better. Then tighten to recomended torque for that size bolt. I would not use lock washers they tend to break or not hold the torque for long. A locking type nut or loctite would be better. Just make sure the hole isn't elongated if it is go to a larger dia bolt. Good Luck

 

we used to remove the rear radious rod strut hangers that were riveted in on the old 78 ford one tons all the time and we bolted them back with grade 6 with nylon lock nuts and a burb gun. grade 6 will allow more stretch than a grade 8. from what i have always been told the rivets were used to allow flex grade 6 or 8 i think you will be more than safe.

 

Big trucks have the crossmembers bolted in. I always figured if it's good enough for the big trucks its good for the little ones too.

 

Genuine old-timey rivets are tighter and can't loosen, as they are installed red-hot and draw up as they cool.

That being said, grade-8 bolts will hold plenty good enough for a truck-frame.

Use fine-thread for more precise tightening and the next size smaller flat-washers on both sides, i.e. 7/16 flat-washer on 1/2 bolt, etc.

I don't recommend split-lock washers in critical applications.

 

You might look into using Huck bolts, that's what big trucks have.

 

Trooperthorn...

My Crew has been running in a constant state of abuse for years in both trail riding/towing use with a cross-member bolted in with grade 8 bolts/flat washers.

The top bolts as you know are a SOB to remove with the body on the frame so take that into account when you reinstall...(it will be self explanatory if you look at it)

Ya figure out how your doing your fuel tank yet?

NoRM

 

My bodyshop friend says use grade 8 and drill out the rivet hole to the next size up along with a larger diameter bolt.

 

I'd suggest using an all metal interference thread nut rather than a nyloc. You only get one use out of them but they retain torque better.

 

Thanks all for the info. Especially about the lock washers. I can't even count how many times I have pulled a bolt and found a broken washer. I found today that my crew frame is an inch deeper than the 92 frame. It ads a new wrinkle to transferring crossmembers. I think I have it figured out.