martinf Posted May 11, 2009 Share Posted May 11, 2009 Hey all,I got a '65 B set up as a dump truck. I cracked the frame rail all the way top to bottom (can you say too heavy of a load?!)So, I was planning on grinding out the crack, welding that up, grinding flush and putting a big fish plate reinforcer on and welding it up good with 7018.Then I happened to see in the maintainence manual "Hints about frame repair." They enocurage welding cracks, but strongly say to NOT weld reinforcing plates, but instead bolt them in.Hmmn, why would you weld the crack but then not be able to weld plates? I know about stress cracks and what all, but I thought that the fish plate appraoch eleviated that a lot. And then searching on this site, I see differing opinions about welding or bolting frames. At the rish of stirring this old controvery up again, I'd like to hear some more opinions about this....thanks,~martin Quote 1965 Mack B-74, dump1974 Mack R, logging w/Prentice self-loaderwww.somewhereonthemountain.blogspot.com Link to comment Share on other sites More sharing options...
BobsLandscaping Posted May 11, 2009 Share Posted May 11, 2009 My brother is a welder in the Boilermakers Union. Won a bunch of awards from the AWS, AWS master welder, Welder of The Year, Apprentice of the Year before he became a Journeyman, graduated top of his class at Lincoln Electric Welding School, certified to weld in Nuclear Power by the NRC, has a BS in Welding Technology from LCSC, in short he's one of the best welders in the world. Easily in the top 10 list. He saw this and said that a properly welded joint is stronger than the metal surrounding it and that a proper weld on a truck frame can cause no problems. It's improper welds that cause problems.There you have it, another opinion to debate over. Quote Link to comment Share on other sites More sharing options...
HK Trucking Posted May 11, 2009 Share Posted May 11, 2009 My opinion:The crack is already broken, so welding is the only way to repair it.Once the crack is welded, you bolt on the reinforcements instead of welding them on, because the heat ofwelding around the edges of the reinforcements would alter the metallurgic characteristics of the frame in the weld zone, possibly causing a future crack or break there.. Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment Share on other sites More sharing options...
theakerstwo Posted May 11, 2009 Share Posted May 11, 2009 My opinion:The crack is already broken, so welding is the only way to repair it.Once the crack is welded, you bolt on the reinforcements instead of welding them on, because the heat ofwelding around the edges of the reinforcements would alter the metallurgic characteristics of the frame in the weld zone, possibly causing a future crack or break there.. Your right. Dont weld on a frame unless you have to. Ever try bolting a crack together? No so you weld it together. And i dont grind the wqeld down on b oth side either. Just so the fish plate will set flat on the side to the frame and the olter side of the frame let the weld stay on the frame. Quote glenn akers Link to comment Share on other sites More sharing options...
fjh Posted May 12, 2009 Share Posted May 12, 2009 Your right. Dont weld on a frame unless you have to. Ever try bolting a crack together? No so you weld it together. And i dont grind the wqeld down on b oth side either. Just so the fish plate will set flat on the side to the frame and the olter side of the frame let the weld stay on the frame.Agree Weld the crack bolt the insert!If you are not a welder your best off doing it this way! If not done correctly just welding will break again. Also smooth the flanges as best you can that is where the crack will likly start again! Quote Link to comment Share on other sites More sharing options...
ducky698 Posted May 12, 2009 Share Posted May 12, 2009 Agree Weld the crack bolt the insert!If you are not a welder your best off doing it this way! If not done correctly just welding will break again. Also smooth the flanges as best you can that is where the crack will likly start again!Hi, the frame on my Flintstone has been cut in half and extended by 3 feet, it must have been done atleast 20years ago and has been pulling roadtrains and been put through the roughness of a mine site and its still together. I have to do some more work on the frame and have an engineer next to me, his advice to me is grind out the frame on a 45degree angle where a crack may be and then heat metal a little then weld it and let it cool down as slow as possible.all my cross beams are split and have to be done, then I will add a fish plate as per the mack specifactions.regards Grant Quote Link to comment Share on other sites More sharing options...
ducky698 Posted May 13, 2009 Share Posted May 13, 2009 Wonder if this one was welded?? Quote Link to comment Share on other sites More sharing options...
BAD DOG Posted May 15, 2009 Share Posted May 15, 2009 I would V the crack out withe the grinder. Heat the cracked area up a bit with the torch and let it cool abit and weld it real good wit some 7018 rod. It 'll proably never break in that spot again. Probably should fish plate it inside by rights, use bolts don't weld it in. My friend and I stretched a frame afew years back, we even ground the welds off smooth on both sides of the frame and hid our splice , we never had a problem with it. Quote Link to comment Share on other sites More sharing options...
martinf Posted May 15, 2009 Author Share Posted May 15, 2009 Hey everybody,Thanks for all the great advice. I'll take it! and weld the crack and bolt a fish plate with grade 10 flange bolts.It's my own dang fault this happened in the first place. As some of you amy remember, this truck was the one I popped a serious wheelie in last year when I was trying to haul a 10 ton 20 ft long barge section up a gravel mtn road. WHen I popped the wheelie I also cracked the frame.Live and learn.~martin Quote 1965 Mack B-74, dump1974 Mack R, logging w/Prentice self-loaderwww.somewhereonthemountain.blogspot.com Link to comment Share on other sites More sharing options...
OneWelder Posted May 18, 2009 Share Posted May 18, 2009 do not make the fish plate stronger than the frame - this could result in a stress point cracking the frame again - ie 1/4 thick frame use 1/4 plate Quote Link to comment Share on other sites More sharing options...
Mark from OZ Posted May 18, 2009 Share Posted May 18, 2009 Wonder if this one was welded?? Nope. but soon will be......... Quote Link to comment Share on other sites More sharing options...
Speed Posted May 22, 2009 Share Posted May 22, 2009 Something else to consider is when you drill the holes,smooth the edges of the holes, counter-sink each oneslightly. This will keep stress cracks from starting from the holes,because it removes any irregularities for cracks to start from. (Don't ask me how I know this is true. ) Speed Quote "Remember-ANY Gun Control is Unconstitutional!"<!--sizeo:3--><span style="font-size:12pt;line-height:100%"><!--/sizeo--><i><b>MACK-E Model Registry # 36</b></i><!--sizec--></span><!--/sizec--><a href="http://www.nvabatetravel.com/"target="_blank">http://www.nvabatetravel.com/</a> Link to comment Share on other sites More sharing options...
other dog Posted May 22, 2009 Share Posted May 22, 2009 Something else to consider is when you drill the holes,smooth the edges of the holes, counter-sink each oneslightly. This will keep stress cracks from starting from the holes,because it removes any irregularities for cracks to start from. (Don't ask me how I know this is true. ) Speed Hi Speed, welcome back! Quote Producer of poorly photo-chopped pictures since 1999. Link to comment Share on other sites More sharing options...
other dog Posted May 22, 2009 Share Posted May 22, 2009 Hey everybody,Thanks for all the great advice. I'll take it! and weld the crack and bolt a fish plate with grade 10 flange bolts.It's my own dang fault this happened in the first place. As some of you amy remember, this truck was the one I popped a serious wheelie in last year when I was trying to haul a 10 ton 20 ft long barge section up a gravel mtn road. WHen I popped the wheelie I also cracked the frame.Live and learn.~martinoh yeah, I remember those pictures now! Quote Producer of poorly photo-chopped pictures since 1999. Link to comment Share on other sites More sharing options...
mackdaddy1911a1 Posted May 23, 2009 Share Posted May 23, 2009 I remember the pictures of the B-wheelie. That was a wild ride. Best of luck with the frame repair let us know how it goes.Matt Quote THE GREATEST NAME IN TRUCKS MACK TRUCKS Link to comment Share on other sites More sharing options...
martinf Posted May 29, 2009 Author Share Posted May 29, 2009 I remember the pictures of the B-wheelie. That was a wild ride. Best of luck with the frame repair let us know how it goes.MattSInce you asked...Here's how it's goingI've got the crack welded up with 7018 after grnding out and pre-heating. Went okay, though I'll admit that vertical welding is not my specialty.I got all the bolts off so there's plenty of real estate for a reinforcing plate. In fact, there's already quite a few holes in there frame that I can use by drilling matching holes in the reinforcing plate and using longer (and higher grade) bolts in the original holes. A couple of questions:On the inside of the frame rail towards the front of the crack (the crack is exactly above the overspring pad), there was already a big reinforcing plate boltied thru (see the front four holes in the pic). This is factory done, correct?I'm thinking to put in a reinforcing plate as tall as the frame and 20" long (say 10" each side of the crack). I can't go any farther back than the trunion pedastal bracket, but I can use all the exsisting thru holes to help bolth this thing in.My other question concerns the top of the frame. Should I bend the reinforcing plate up and ontop of the frame rail?I could cut out a section of that 1/4" x 3" steel that lying on top of the frame. And, if I were to do that, how would I attach it on the top? If I flange bolted it, the bolt heads would protrude and mess with the dump bed. I suppose I could countersink the bolts or how about welding a lap seam up there on the inner edge of the frame rail C channel?Or for that matter--and I promise this is the last question--how about just welding that exsisting 1/4" x 3 steel flat thats lying on top of the frame rail? WHat is that piece of just tacked on steel for? To keep the dump bed from rubbing the frame? (I guess that was one more question).Hey, I really appreciate you guys taking the time to answer my newbie questions. This site is really great and you all have been really good to me.thanks,~martin Quote 1965 Mack B-74, dump1974 Mack R, logging w/Prentice self-loaderwww.somewhereonthemountain.blogspot.com Link to comment Share on other sites More sharing options...
HK Trucking Posted May 29, 2009 Share Posted May 29, 2009 Don't drill & bolt thru the top or bottom frame flange, bolt thru the side of the frame only.Usually that metal strip on top of the frame is to compensate for the thickness of the hoist frame at the front, so the dump box will sit flat instead of resting on the hoist frame at the front, and having a gap the rest of the way. Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment Share on other sites More sharing options...
martinf Posted June 5, 2009 Author Share Posted June 5, 2009 Well, I got the frame repair done.Welded the crack (7018, after grinding out and pre-heating) then ground flat and botled on a reinforcing plate 1/4" by 9 1/2" wide by 24" long (angled sides).For thru bolts, I used some exsisting open bolt holes. I didn't like the fact that they were in straight lines, but the holes were already there which seemed to trump the "no straight line" rule. Also, the holes went thru exsisting frame support members, like cross frame etc. and that seemed especially a good idea. I had to drill a few more, too. I used 1/2" flanged frame bolts. Turned out pretty darn good and I don't think I'll have to worry about this frame. In this pic, there's still another bolt to do up towards the top on the left side.Thanks for all the assistance. I learned a bunch about frame repair from you guys.~martinAlso got new trunnion cap bolts on. The caps were so loose, you could turn most the bolts by hand! Quote 1965 Mack B-74, dump1974 Mack R, logging w/Prentice self-loaderwww.somewhereonthemountain.blogspot.com Link to comment Share on other sites More sharing options...
Rob Posted June 5, 2009 Share Posted June 5, 2009 Well, I got the frame repair done.Welded the crack (7018, after grinding out and pre-heating) then ground flat and botled on a reinforcing plate 1/4" by 9 1/2" wide by 24" long (angled sides).For thru bolts, I used some exsisting open bolt holes. I didn't like the fact that they were in straight lines, but the holes were already there which seemed to trump the "no straight line" rule. Also, the holes went thru exsisting frame support members, like cross frame etc. and that seemed especially a good idea. I had to drill a few more, too. I used 1/2" flanged frame bolts. Turned out pretty darn good and I don't think I'll have to worry about this frame. In this pic, there's still another bolt to do up towards the top on the left side.Thanks for all the assistance. I learned a bunch about frame repair from you guys.~martinAlso got new trunnion cap bolts on. The caps were so loose, you could turn most the bolts by hand!Glad to see you did the job right. I'd feel safe operating the truck with that repair.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
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