Cracked frame - repair or trash it?

[Big Daddy Bear]

Been distracted by other priorties for quite awhile, but pulled the truck into the barn today so it could dry out before stripping the cab & bed off of the donor truck to start prepping the frame.

The frame has cracked at the top of the arch over the rear axel, it is broken clean through.

I want to build off a stock height, factory frame.

It took me awhile to find this doner truck, specifically for a stock frame, because the other one was butchered by a previous owner and unusable.

The butchered frame is a 3600, the damaged frame is a 3100 and the arched sections over the axels of the each frame are different. Could I cut a soild section out of both sides of the 3600 frame and replace it in the 3100?

Is it worth while to patch and reinforce the damaged area or toss it and go on the hunt for another frame??

Got to do a little resizing, then will have some pictures to add.

Thanks....

[mongocanfly]

I don't see why not..I've cut, welded and shortened many a frame..wouldn't be much different than when these boys c-notch a frame for axle clearance when on bags.if your confidant in your welding I say go for it,, if not I'd get a good welder to do it for me..if its not to bad a break I see no reason why you can't weld it and for good measure go ahead and box that section while your there.

[Big Daddy Bear]

Close-up of cracked area on the 3100 frame, differences in amount of curve between 3100 & 3600 frames.

If patching it would be viable, I figured I would cut a section forward of the axels to connect, then trim off the extra behind the axel to bring it down to shortbed lenght...

Thoughts?

[Big Daddy Bear]

Originally Posted by mongocanfly

I don't see why not..I've cut, welded and shortened many a frame..wouldn't be much different than when these boys c-notch a frame for axle clearance when on bags.if your confidant in your welding I say go for it,, if not I'd get a good welder to do it for me..if its not to bad a break I see no reason why you can't weld it and for good measure go ahead and box that section while your there.

Yeah, thought about that. Just wasn't sure about the difference in the amount of curve between the 3100 & 3600 frames possibily causing some type clearence problems or rubbing?

There must be some reason they are that different...no???

[Big Daddy Bear]

And the shock mounting location, inside frame rail on 3600 and outside on 3100.

Have not done any measuring, but are the frames different widths??

[Boom]

I wonder if the reason it broke was because of the spring being placed there and it couldnt handle the added stress, or if the frame broke and they put the spring there to "help" it last longer.

[mongocanfly]

The big curve frame has the axle on top of the springs and the flatter frame has axle under the spring. That is a pretty bad crack. That coil spring and a heavy load may have been a factor to the crack.

[Big Daddy Bear]

I wondered that about the extra coil spring set, seems too close to the break to not think it may have had something to do with it.

I am thinking I will go ahead and pull the bed & cab and see what the rest of it looks like, then go from there.

[67 chevelle]

Its accessible so if it were me Id weld it , then run a box plate on both frame rails , would be stronger than stock , sand blast it first to get rid of the rust

[mr48chev]

Mine broke in the same spot the same way because the axle was banging on the frame as I have about 1-1/2 inch clearance between the axle and the frame.
I'd get the frame lined up all square, V and weld the crack and then plate it on the inside top, side and bottom and box both rails for the length of the curve and be done with it.

If you are planning on lowering it you could put a small C notch in it and then put a bit of a raised support on top along with boxing the inside. That's what I plan to do with the frame I have when it goes under a different cab when the 48 gets done.

I actually drove my 48 into my buddies yard with the broken frame and we lifted the bed up and repaired the frame in his driveway.

[Big Daddy Bear]

Thanks fellas, got the bed off, dosen't look so bad now.

Not going to lower it, want stock height and look.

Next step get the cab off and see if there are any other surprises...

Thanks again, you guys confirmed my initial thoughts.

Appreciate the feedback!!

[67 chevelle]

do a build thread or continue this one , love to see your truck and the progress as you work on it

[Big Daddy Bear]

Originally Posted by 67 chevelle

do a build thread or continue this one , love to see your truck and the progress as you work on it

http://67-72chevytrucks.com/vboard/s...d.php?t=661743

Figured out how to add the link to my build thread last night into my signature line, so hopefully it will be in all my posts from now on...

[_Ogre]

the engineerd in me says the crack is a direct result of the additional flexing from the coil spring
as long as you remove the coil spring and do the patching with plates i don't see it being a problem to patch it

read the thread in my signature to get the year of your truck in your signature line
we still don't know what year your truck is

[Big Daddy Bear]

Originally Posted by _Ogre

the engineerd in me says the crack is a direct result of the additional flexing from the coil spring
as long as you remove the coil spring and do the patching with plates i don't see it being a problem to patch it

read the thread in my signature to get the year of your truck in your signature line
we still don't know what year your truck is

I think so too, and they are going away!! When I get the cab off, I hope to not find any more issues under it, then plating & boxing will be next.

Looks like the signature is fixed now, thanks!!

What was a very rusty 5-window will become an almost rust free 3 window.

[OrrieG]

If it has been loaded down enough to crack in that location I would carefully inspect the rest of the frame for smaller cracks, especially around the spring shackles. Those coils may be there because the original springs are shot.

[Big Daddy Bear]

That is why I am not getting too excited about it until I get the cab off and clean it up.

Am hoping that is all there is, but will see soon enough!

[tmoble]

What the other guys said. clean it around that crack, V it and weld it back. plate the outside and box the inside, good as new. get rid of that coil spring, it's not part of a 50s Chevy truck and probably the cause of the problem.

great avatar BTW.

[Big Daddy Bear]

The avatar just seemed so perfect.....

[_Ogre]

Originally Posted by Big Daddy Bear

The avatar just seemed so perfect.....

it did not go un-noticed
very appropriate for our hobby
we should all be using your avatar