Shortening up a Truck Frame

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Hello, My end goal is to take about 18" out of a truck frame. The truck is a old highway tractor that has been converted to a dump truck, and there's a good bit of extra frame that had not been taken out. I've talked to several folks, all experienced in this. Some say it's better to slide the suspension foreward. That would give me about 32 I figured extra holes in my frame which doesn't sound all too appealing. Others have said to cut the frame in a Z style and fish plate it. Some have said to cut the frame straight, weld it up and place a crossmember dead in the middle of the cut. Others say to cut the frame in the Z, double the frame about a foot on each side of the cut and bolt that in after welding the Z up. There's few more ways people have suggested but I think you all get the point. It seems like everyone you ask has a different 'right' way. What I want to know is what is the 'most' right way to do this?1942 Lincoln Lincwelder 180, 2 Cylinder Wisconsin Gas1981 Lincoln Shield Arc 250, 3 Cylinder Perkins DieselLincold Idealarc 250 Roundtop AC DC+ DC- (80's)Miller Millermatic 250x
Reply:Push the axle up and drill the holes, period.  Your looking for the easy way out and when it is said and done I doubt a proper cut/weld job is going to save you much if any time.  If you really think you need to- try to rent/borrow a frame drill, but really 30 couple holes you will have knocked out in no time if you can sharpen a drill bit good.
Reply:Do not cut the frame unless you have no other options. Drilling holes is far simpler than cutting the frame. Only cut the frame if you have someone on hand that KNOWS the correct way to do it.
Reply:Roll everything forward and cut off what is hanging out.Disclaimer; "I am just an a$$hole welder, don't take it personally ."
Reply:What make and age is it? Do you have any idea of alloy or heat treating? What do you not like about moving the axle forward; are you worried the old holes in back will cause loss of strength? If so, bolt plates there to give it added strength.Pictures of the frame would go a long way in showing readers what the physical situation is.
Reply:Drill new holes.  A bridge reamer makes this task a lot easier or a frame drill.  Watch out for those hidden air lines on the back side of the frame.  Dan
Reply:As far as DOT is concerned i dont believe that you are allowed to have any welsf to the frame infront of the rearmost spring hangers. just my .02Miller Big 40GMiller HF-251 D High FreqVictor OA Lincoln 135 MigMK 3A CobramaticBridgeport J HeadCronatron OxylanceRadnor ACAG TorchWeldcraft TIG Torches1 blown knee and two 5 Gallon pails away from being a hero.
Reply:truck frames are heat treated DO NOT CUT with a torch !!!!!! you will have a lot of problems with it cracking i dont even suggest drilling but if your going to cut the frame use a cold saw or saw zall cut it really straight NO Z cuts go get about 12 feet or more of c frame like off a old mack or freightlinner and  a ton of 3/4 grade 8 or better bolts .... bring both halves together and stuff about 6 feet or more of  frame   and bolt together good luckLincoln Power Arc 4000 Thermal Arc Fabricator 252 iThermal arc 186Thermal Arc 26 tigTweeko 200 amp spool gunHobart AirForce 400WP-17V-12R
Reply:I have all ways cut frames of square and welded with no plating. It looks like drilling would take more time but you wouldnt have to test your welding skills out. Why do you need to do it if truck has been around the block like you say could you leve it as is? Its a big job if you havent done it before.
Reply:[  I did my 89 International,(former oil truck) Move the gear forward and drill the holes, cut off what you don't want behind the frame. Really I have done this and it is not that bad at all if you get some good cobalt or HS steel bits. Not some cheap junk. I did mine when the frame was bare, no bed installed. We  put the frame on some jack stands and heavy timbers, cut all the rivet heads in the spring hangers,let em cool and pound them out with a BFH and drift. Find a landmark on the frame and take equal measurements to locate your axle. Set the spring hangers the same height in relation to the top of the frame as they are before removal. I took a bit the same size as the holes and drilled each hole through the hangers just to mark the center of each hole. Then move the axle out of the way and go to it with a small bit progressing up to the size you need. If you have a truck or spring shop get some new bolts from them, Grade 8 at the minimum if you don't have a spring shop.   heres the frame, did it in my garage at home. Also no joint in the frame may be a benefit it you get inspected or want to sell it down the line, clean job on the drilling and no one but you will ever know it was altered. If you own, or can rent a Mag drill, piece of cake. I have one now but didn't when I did this.    good luckAnd the almost finished projectLast edited by kolot; 02-06-2012 at 09:29 PM."Si Vis Pacem Para Bellum"Lincoln Idealarc 250 AC/DCMillermatic 251   Syncrowave 300   30A spoolgunLincoln MP210Hypertherm 45(2) LN 25(2) Lincoln Weldanpower 225 CV(4) SA200   1 short hood    SA250    SAM 400
Reply:I wasn't the welder, but helped with fitment, plumbing and electrical on 3 Semi frame jobs lately.  All three were cut with plasma and installed cross-members where the welds were.  Also double framed 4' on either side of the welds (18' frame section added on each side).  Two of which we stretched the frame 9' (30' rollback beds).  The third was shortened 8' (old stretch) to accommodate a 16' dump bed. Been two years on the stretches, hauling as much as 20k lbs.  Its been a year since we shortened for the dump bed.  Not the first crack yet.  I'll get some pictures up tonight.We did have a frame drill and reamer bit to ease with bolt installation.  5/8" flanged L9 bolts I think?Last edited by paintman40; 02-21-2012 at 04:00 PM.
Reply:On a stretch job there is no getting around the welding, but on shortening what is the benefit to cutting the frame and welding? I can't believe you would save time in a properly fit and welded joint vs. drilling new holes and rebolting. But I am assuming air guns for the bolts and good drills and bits? Probably talking maybe what? 32 holes through under or around 1/2 material. Takes a while but on the other hand blocking bothe sides of the frame up, cutting, fitting, beveling , then welding the joint, Fabbing and welding a fish plate or double frame area, heat stress, wether it is OK or not OK the weld in the zone of the frame, just seems like a home run to drill new holes and have a virgin 1 piece frame providing it is a straight channel frame as mine and most are.   Further with the concerns for trailers, and trailer hitches with liability here , I am surprised the guys aren't all over this with Liability issues.   Also for you guys that don't know this, there is a huge difference between sharp quality bits, and old cheap junk you have laying around, if your going to work with steel, get good bits from tag sales or flea markets and go get yourself a drill doctor, they are the best. Drill low RPM, moderate to heavy pressure,oil or coolant, if your aren't producing curls and large chips your wasting your time.Last edited by kolot; 02-21-2012 at 09:08 PM."Si Vis Pacem Para Bellum"Lincoln Idealarc 250 AC/DCMillermatic 251   Syncrowave 300   30A spoolgunLincoln MP210Hypertherm 45(2) LN 25(2) Lincoln Weldanpower 225 CV(4) SA200   1 short hood    SA250    SAM 400
Reply:A rented Hougen mag drill with appropriate rotabroach would be quite the timesaver.
Reply:Originally Posted by DanD78Drill new holes.  A bridge reamer makes this task a lot easier or a frame drill.  Watch out for those hidden air lines on the back side of the frame.  Dan
Reply:A frame drill can be a magdrill. I've also seen them made with 2 trailer jacks. One supporting the weight of the drill, and the other chained around the frame, sucking it in.Miller: 200dx, Bobcat 225, Passport, Powermax 45, Milwaukee: Dry Saw, MagDrill, grinders
Reply:The frame drill I saw was at a shop that did a lot of frame work.  It is drill press on wheels you can roll up to the frame.  It is adjustable up and down. It had chains that you attached to the frame to keep it from pushing away.  I don't think it was home made because it looked like a very nice machine.  They had a long bit extension on it so it would sit outside the wheels and still reach the frame and drill.  Sorry, no pictures.  I have always used bridge reamers but I only do this kind of work every few years.Dan
Reply:We will be shortening a double framed truck in a couple weeks and cutting & welding was never even discussed. We will be drilling it.Millermatic 200Hobart Handler 120Victor O/A & Ramco BandsawLincoln 225 ACSnapOn AD HoodMiller XMT304/22AHypertherm Powermax 1650 G3Lincoln Idealarc DC600 w/Extreme 12 VSMiller Digital Elite "Joker"
Reply:Originally Posted by farmallA rented Hougen mag drill with appropriate rotabroach would be quite the timesaver.
Reply:http://www.zipcut.com/One variant of frame drill.      broach is way quicker though.  For a PERSONAL truck that im going be putting some miles on i like to broach undersize then hit the holes with a bridge reamer to finish.Vantage 500's LN-25's, VI-400's, cobramatics, Miller migs, synch 350 LX, Powcon inverters, XMT's, 250 Ton Acurrpress 12' brake, 1/4" 10' Atlantic shear,Koikie plasma table W/ esab plasmas. marvel & hyd-mech saws, pirrana & metal muncher punches.
Reply:Originally Posted by Old DougWhy do you need to do it if truck has been around the block like you say could you leve it as is? Its a big job if you havent done it before.
Reply:It was kinda interesting though on deciding how to go about shortening the rig up, between on here and talking to folks around here weather they be reputable welding shops or reputable mechanics, or the less than reputable shops or mechanics, on how many different ways people have on doing this job. Does anybody on here who may specialize on truck frames know if the FMCSA has any specific rules relating to this?1942 Lincoln Lincwelder 180, 2 Cylinder Wisconsin Gas1981 Lincoln Shield Arc 250, 3 Cylinder Perkins DieselLincold Idealarc 250 Roundtop AC DC+ DC- (80's)Miller Millermatic 250x
Reply:there are rules and regs but theres about as many ways to do a frame strech as there are ways to truck.Vantage 500's LN-25's, VI-400's, cobramatics, Miller migs, synch 350 LX, Powcon inverters, XMT's, 250 Ton Acurrpress 12' brake, 1/4" 10' Atlantic shear,Koikie plasma table W/ esab plasmas. marvel & hyd-mech saws, pirrana & metal muncher punches.
Reply:I know you are going to drill but cuting frame could be done in one day. I wonder how long it will take to move axles and dump bed can it be done in a week or will it take longer ?
Reply:It can be done in a day.Vantage 500's LN-25's, VI-400's, cobramatics, Miller migs, synch 350 LX, Powcon inverters, XMT's, 250 Ton Acurrpress 12' brake, 1/4" 10' Atlantic shear,Koikie plasma table W/ esab plasmas. marvel & hyd-mech saws, pirrana & metal muncher punches.
Reply:One guy can shorten a frame in one Day. Their is no way that one guy can move every thing up in a day.Maybe not everything, but I bet I could get the rear moved in less than a day. Wires, air lines, drive shaft would probably take longer.I've done complete rear swaps with new springs and hangers in less than a day. The only additional time would be laying out and drilling the new holes. If you work off the original holes, there's really not much to it. Doing it by myself, I'd probably take the 5 to 10 minutes to fab up a quick jig to transfer the hole measurements. Something as simple as a length of flat stock or a board with a bolt to stick in the old hole and a hole to mark out the new one with a transfer punch. If everything is shifting forward say 18", every measurement stays the same.It's even faster with the bed off. We swapped out rears, springs and hangers on 2 trucks in less than one day with the beds off both trucks. Figured since we had the bed off anyways, we'd do everything at once while it was easily accessible and save the hassle later..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Sorry for the long delay, but I ended up getting a Hougen mag drill and slid the suspension foreward. I messed up and didn't get a picture of the truck with the box on it to show how damned goofy it looked, but these pictures should give you an idea, Anybody who'se out there who is thinking about tackling a project like this, Please feel free to get in touch with me I will be glad to give you some advice that I learned on this project. After doing one of these I feel like the next one will go a lot quicker. The front of the bed sat right at the front of the hoist frame you can see in the picture, the 2nd picture is right after we set the bed back on it, talk about a sigh of relif when it set down right into place!  The truck's been working fairly steady since the 1st of April with no problems (any more than any other truck) and is sure a lot nicer to jockey around a jobsite now that the old girl's 22" shorter! Attached Images1942 Lincoln Lincwelder 180, 2 Cylinder Wisconsin Gas1981 Lincoln Shield Arc 250, 3 Cylinder Perkins DieselLincold Idealarc 250 Roundtop AC DC+ DC- (80's)Miller Millermatic 250x