Welding to 5th wheel?

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My opinion has been sought regarding the "pinning" of a fifth wheel plate for use with a frameless dump trailer.  The tractor has a conventional setup for a tanker (or any other frame trailer), but wants to also use a frameless that needs the fifth wheel plate to be fixed, as the trailer setup does the pivoting.I have done some looking, and see a couple ways guys are doing this, but to me they look kind of scary. One option was to support the 5th wheel plate at all 4 "corners" with removeable shims that fit in welded pockets.  I actually saw this setup in person, and also saw the crack in the plate that it caused. Likely since the main pivot pin no longer supports the trailer. I think his shims were too tight, and the soft bushing in the main pivot wasn't accounted for.The other option that I found in photo's, involves pinning the rear of the plate only, to the frame, with a simple setup of 3 hunks of pipe or tubing and a pin, just like you would build a hinge. This requires that you weld to the 5th wheel for sure, and probably the frame, unless a bolt on option could be worked out. I liked this better, as the original pin still bears the bulk of the load, and the pin just keeps it from pivoting.I'm not doing the job, but it is one of those situations where it is going to get done anyhow, and I may be able to help it happen more safely. Can a 5th wheel plate be welded to, at the rear edge, safely?Has anyone done this? Jason? Anybody?
Reply:I have never ran across an instance where a 5th wheel had to be "Pinned" SOLID.  Just doesn't make sense to me.We run frameless dumps up here as well but all the tractors run regular pivoting 5th wheels as they often deck-off the dump trailers and grab log trailers, or lowboys, or tankers etc etc...Never even HEARD of pinning a wheel solid.Sorry, can't be of much help.Later,Jason
Reply:I drive a truck that used to pull a frameless and has the locks at just the rear of the 5th wheel, i can take some pictures tomorrow if you want-NateMiller Trailblazer 302gMiller Spoolmatic 30aLN-25 x 2Idealarc SP200Hypertherm Powermax 600
Reply:Holland makes a kit for this,  the only time the kit will not work is if your truck has long custom lowbed ramps like mine.     The price of the kit is very reasonable and comes with specific welding instructions.     Other 5th wheel manufacturers also have these.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:Thanks for the responses guys. Jason, I had the same reaction as you when this first came up. Now, I don't do much work on big trucks on a regular basis, so I started asking questions.  I can't really explain it without a picture, but fixing the plate made sense once I saw the trailer setup. I just didn't like the home grown method the guy used.NV welding, If it's not much trouble, I would appreciate a look at one that is done right. Thanks in advanceDualie, I spent about half an hour cruising Hollands site, and didn't find the kit, but did find some generic weld procedures that called for ER70xx lo-hy, and "sound" welding procedures.  The plates appear to be cast steel as far as I can tell.  At this point I think adding a pin to the rear of the plate looks feasible.
Reply:I have seen guys run without the plate pinned, and every time they start and stop, the plate SLAMS forward and rearward. Jason, I have never seen one that WOULDN'T require it pinned. Actually, the repair I did in my trailer thread, are the bushings that the trailer pivots on after you "lock out" the fifth wheel plate. I would like to see their setup's, because that has REALLY got me stumped. I'm NOT telling you you're wrong, just saying SOMETHING has to be missing here.Daddy, I can try to make it to my yard tomorrow and take some pics. My puter is running REALLY slow, so if you want, PM me your email, and I will send them to you and you can post them here, if you don't mind. My truck was done by a professional shop. It has the tubes and 1 1/4" (I'm pretty sure) bar thru them on the rear of the plate. There is a kit available by me, if you can't find one. Let me know and I can get you the info. I'm pretty sure they would ship you one out. Or you can make one yourself. I will try to get dimensions, if you want. If you go that route, make sure you ask them what procedure/filler metal they use. I have seen ALOT of home made ones crack because of the plate material, I would imagine. Good luck!"Where's Stick man????????" - 7A749"SHHHHHH!! I sent him over to snag that MIC-4 while tbone wasn't looking!" - duaneb55"I have bought a few of Tbone's things unlike Stick-Man who helps himself" - TozziWelding"Stick-man"
Reply:I will keep an eye on this thread with interest - I enjoy learning something NEW as well.  Maybe it is just the difference in the manufacturers from down there to up here, but I do not recall ever coming across this.  Maybe I just never took the time to look close enough.  We have some companies in town that regularly switch back and forth to quarter frame end dumps and I honestly do not recall seeing any special attachments on their 5th wheels.I fully understand what you are saying Dean, and it makes sense by looking at YOUR trailer.  Good Stuff.Last edited by Black Wolf; 05-23-2012 at 09:23 PM.Later,Jason
Reply:Originally Posted by Black WolfI will keep an eye on this thread with interest - I enjoy learning something NEW as well.  Maybe it is just the difference in the manufacturers from down there to up here, but I do not recall ever coming across this.  Maybe I just never took the time to look close enough.  We have some companies in town that regularly switch back and forth to quarter frame end dumps and I honestly do not recall seeing any special attachments on their 5th wheels.I fully understand what you are saying Dean, and it makes sense by looking at YOUR trailer.  Good Stuff.
Reply:-NateMiller Trailblazer 302gMiller Spoolmatic 30aLN-25 x 2Idealarc SP200Hypertherm Powermax 600
Reply:I had to make a "custom" set for my heavy haul truck to pull the clement scrap star.    I had to go from the rear of the wheel parallel to the frame rails and used 2" pins slightly turned down and fit into xx wall 2" pipe and 3/8" gusset towers off of the slider plate.    I used NR-232 with a 350ish degree pre-heat for good measure and to burn out the grease paint and crud from under there.   I kept it to the non load bearing portion of the plate and followed it up with some rustoleum gloss black spray paint for good measure.heres the official Holland kit http://literature1.safholland.com/qu...W337_en-US.pdfLast edited by Dualie; 05-24-2012 at 01:38 AM.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:Well guys, this is working out ok. I saw what they did today, and watched the truck dump a half dozen times or so. They used heavy wall tube, like half inch wall, by inch and a half I.D. , and  an old axle shaft from a mack for the pin. Fits nicely, and no slop. Welded with shopmate 300 and lincoln ER 70s6 wire with pre-heat on the casting. The tube and pin are overkill for sure,and the welds to the 5th wheel frame are good, but the important part where the tube welds to the casting is the weak spot. I would have made the fitup much better, but at least I have the luxury of being able to watch this setup and fix it if it has trouble. Nothing is going to fall off the truck, but if the weld cracks where he attached the tube to the back of the plate, I will not be shocked. Even with pre-heat he has a cold start on one side with the mig... I am surely not the best, but I swear, you should not be allowed to touch a wire feed till you really know how to weld...I'm glad I brought this up, cause I'll bet you a dollar someone will read this and do a better job of this conversion. There are probably thousands, if not more, hack versions of this out there. These frameless trailers are getting real popular because of the payload. Our guy was pulling 27 ton legally, compared to 24 or so on our lightest triaxle.
Reply:Here are a couple of Stick-man's pics of his setup. Thanks for sending these by the way.And a question for ya... Is that a crack in the 5th wheel in the first pic related to the pin setup? Attached ImagesLast edited by daddy; 05-25-2012 at 08:47 PM.Reason: clarity