Gurus need your help

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well while doing some work on my 99 Chevy z 71 i came to find my frame was cracked in half right behind the back bump stop for the rear axle like the last 2 feet of frame anyway Chevy wont do anything(not surprised) and they suggest i replace the whole frame rail. not happening reason being is there is dimples in the frame that are supposed to make it crumple in a rear end collision  funny thats where it split .so they say if i weld it it may make the frame 2 strong i have seen several other 99s without these dimples so I've came to the fact that i have to take off the bed etc and weld it up with supports i would appreciate any advice from you more seasoned guys in how you think i should re enforce it for welding thanks for any info i can take more pics if needed thanks 350P 30A spool gun cut master 51  syncro 250 other stuff " take a dog off the street and make him prosper and he will not bite you sad the same cannot be said for man" i didnt use punctuation just to piss you off
Reply:That's one of the straightest breaks that i've seen in awhile. I would try to find a truck with heavy front end or other side damage and seen if they would part with a section of the frame for little cash. It looks like there is a factory welded splice about a foot fwd of the break. I would grind out that weld and replace frame rail from the welded splice to the rear. The odd shapes that they make frames nowdays make them more difficult to make effective doublers for frame splicing.
Reply:I would vee it out, weld it UP, plate it.  Don't weld the plates perpendicular to the frame, or don't weld across the flanges.Nice job, do a search, there are a few frame repairs posted here.7018 or mig, plate as thick as the frame.DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:You know I was going to ask the same thing about my truck. I have a 95 Dodge 3500 with an 11' utility body on it.  Now keep in mind that this truck has 541,000 miles on it!  The frame is broken behind the cab where the body mounts to the frame.  I fitted a 3/8 plate behind it about 6" past each side of the crack and radiused the edges so it fits tight in the channel and then I used 8 1/2" grade 8 bolts, 4 on each side of the crack. Now I have to weld it up. I an going to vee it out and sandblast the crack good. then I will weld it with some 1/8 7018.  I will have to grind it smooth and paint it with some dirt as the local DOT Officer does not like me! My question is should I box a section of the frame on both sides of the truck where the crack happened? Not trying to butt in but since this is on the same subject..........
Reply:Just curious but did the truck have a receiver hitch bolted on it?  The reason I ask is I have seen SEVERAL chevy frames break in this location from the leverage created by large loads on the receiver hitch.  I've welded several back for friends and certain clients with great success, but it's still not a job I would do for someone walking up off the street.  I doubt if you will have to "V" it out as most of them that I have worked on I could pretty much weld thru with a 3/32"  7018.  Take the bed off,  get it lined back up, and grind it clean.  Then take a fresh 3/32" 7018 at 75 - 80 amps.  Plate it on the sides if you can get enough flat to do it, and weld the top and bottom only.  Do not weld up the side even at an angle as the the first three I plated and tapered the ends all broke again.  This is how I have fixed them in the past.I'm a Lover, Fighter, Wild horse Rider, and a pretty good welding man......
Reply:I will go along with tresi..Take it from there...But MAN!A frame go like that?Not on a Ford.. ...zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Originally Posted by camara My question is should I box a section of the frame on both sides of the truck where the crack happened? Not trying to butt in but since this is on the same subject..........
Reply:Originally Posted by Hammack_WeldingJust curious but did the truck have a receiver hitch bolted on it?
Reply:I vote for the weld and plate suggestions.It would be a job and a half to get another rail, remove the spring hanger, separate the cross-members, cut the welds, -all that twice- and then reverse procedure to install.Probably better heed the warnings to avoid vertical welds on the frame web.
Reply:I welded up some cracked frames on  FORD F-350 econoline airporter busses,years ago. in the rear ,in front of rear springs. I welded up the vertical break,with 70-18  3/32 , ground it smooth, then put on a doubler plate ,about 12" long , welding just across the top and bottom of the plate . held fine . The cracks started ,i believe , because of a (unused) factory hole in the top of the frame- a weak spot .[SIZE="5"Yardbird"
Reply:Originally Posted by umahunteryes i do have a hitch bolted on and do tow a couple boats built like a rock my arse anyway lemme get ya straight are you saying i should plate it on both sides and weld the top and bottom only what about the split?
Reply:After you weld the crack up then weld on your piece of plate. Dont make any welds on the plate that runs crossways on the frame, only lengthwise with the frame. In other words weld the top and bottom of the plate but not the ends.
Reply:4 holes and a Huck gun - no need to weldFire!, Fire! Oh wait, that's my torch...Lincoln PT-225 TIGLincoln 175 MIG
Reply:Vee it out and weld it up, full penetration from the outside of the frame. Clean it up on the inside and put a pass on the inside. Grind the outside weld smooth leaving the flanges alone. Cut a 60 x 40 degree diamond from 1/4" plate and round the corners, about a 2" radius on that size plate. Make the 40 degree width about 1/2 to 3/4" narrower than the frame and weld it on the outside of the frame. Most of the guys that I've talked to that do this regularly do it this way and use 7018 rod. I've done several up to 2 1/2 ton winch trucks this way and never had a problem. Don't leave any craters on the edge of anything to create a stress riser. Oh yea. bigger truck, thicker plate for the diamond.
Reply:Is there some reason that piece of rolled 'C' channel for the bump stop shouldn't be extended beyond the crack or shouldn't have been more centered to begin with? That whole arrangement looks suspicious to me. It looks like it was placed for the sole purpose of starting a crack there. And the crack is straighter than most of my cuts. It's like some engineering concept gone bad.
Reply:It looks to me as if the truck were overloaded such that the frame was bouncing on the bump stops, with the load to the rear (such as on the hitch) and with enough weight and enough hard landings on that bump stop, finally cracked the frame.   I would invest in heavier springs after the frame is fixed.On my '77 Chevy 3/4-ton 4x4, the frame had been cracked behind the steering box.  The crack was welded up, the frame was plated, about a foot long if I remember right, then the inside of the c-channel was boxed with another 1/4" plate, about a foot long too.  The truck survived many more years of abuse and never cracked again.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Originally Posted by SandyIs there some reason that piece of rolled 'C' channel for the bump stop shouldn't be extended beyond the crack or shouldn't have been more centered to begin with? That whole arrangement looks suspicious to me. It looks like it was placed for the sole purpose of starting a crack there. And the crack is straighter than most of my cuts. It's like some engineering concept gone bad.
Reply:Is that piece under the frame a mount for air bags?  Looks like a stress crack from the attachment weld.Never mind, I read the first post again.Last edited by Y2K; 04-27-2008 at 09:39 PM.Reason: Need to read the post
Reply:Originally Posted by Y2KIs that piece under the frame a mount for air bags?  Looks like a stress crack from the attachment weld.Never mind, I read the first post again.
Reply:I'm with Zap, scrap it and get a Ford or a Dodge.HeheheJust kidding, weld it up, and plate it like has been said already.  It will work.Check out the gas tank location in regards to the weld location, apply a healthy dose of common sense and get after it.Mack
Reply:Originally Posted by zapsterNo..Do as little as possible to get by..Don't give them even more reason to look..Or get a Ford....zap!
Reply:If that old dodge didn't get such good fuel mileage I would retire it!  Poor thing gets the snot beat out of it constantly!  But it starts every morning!!!!!!!!!!