I am looking at putting a pintle hitch on my old dump truck. Question is should I bolt or weld to the frame? I have been told not to weld it, but then I see a lot of them welded. What are the pros and cons? I am planning on building box out of plate which will slide into the frame rails. Trying to do things economically as this is an old truck, but I want a good safe setup. Thanks, Marc
I usualy just bolt the new pintle hitch to the rear plate with grade 8 bolts.You will want to put in some bolts through the truck frame into the hitch frame,weld some to.Make sure the pintle is big enough for the load.I use 3/4 inch steel for the rear plate with gussets on the inside.sometimes I weld it directly to the rear of the truck frame.Add bracing & safety hooks on it.
bolt it then weld it....the more the better
Thanks for the replies. Doing both makes the most sense. Now I just need to find a good place to buy some plate at a reasonable price!
The trouble with welding it is it makes replacing a damaged or worn hook very difficult. Mine are bolted only.
My plan is to bolt and weld my plate to the frame. And then like you said Steve, bolt the hook onto the plate.
OK, didn't realize we were talking about the plate. Both my plates are just welded to the frame.
When you do your plate cut it out so you can slide it inside your frame rails. what i did was to make a cardboard template to match the frame rail and then transfer to plate, that way it is a nice tite fit so when you weld it it will be very solid. No need to bolt the plate. Just bolt the hook to the plate, don't weld that.
That's how mine are done dumptrucker, then there are gussets from the portion that extends below the frame back up to the frame.
There is a DOT Reg. on how the plate is installed - thickness , gussets are required If you can not find it I will look up for you the first of week
If you have that information that would be great. All I found was this: The mounting of the trailer hitch (pintle hook or equivalent mechanism) on the towing vehicle must include reinforcement or bracing of the frame sufficient to produce strength and rigidity of the frame to prevent its undue distortion. That is from Part 393: Parts and accessories necessary for safe operation
On my 25 ton hitch I have it bolted with grade 8 bolts a 3/4 thick plated welded to the frame with 1/2 gussets. I had a 20 ton tag trailer, have been stopped by DOT and not had any problems, and they have inspected my hitch and plate a couples time. I don't recall them every measure anything, just inspecting.
The Dot had a section on welding frames , mounting pintle hooks, etc. - they seem to have removed it when they updated website. I should have looked before opening my mouth. I Will add a disclaimer here. as it is to easy to forget something. As I remember it for heavy pintle hooks they required: 1/2 thick gussets forward edge 12" in ft. of plate. these were to be welded on approx. center of bottom frame flange with bottom of gusset angled in close to bottom bolt of pintle hook. Do not weld to edge of frame - it could start a crack - Also use D Rings instead of cutting keyholes for safety chains( this maybe ins. Co. requirement) I usually us 3/4 pl. and cut bottom corners for gussets also use I use 7018 to 12018 welding rod depending on the frame in truck. figure height and punch or predrill holes for pintle before welding in place My experience has been that dot does not bother people on this as long as looks like a good installation part of which means no bubble gum welding
I meant to add this
Thanks one welder.
I should add use preheat- do not try to cool off rapidly and do not weld in extreme cold unless u can it keep warm
I understood that welding on/to a truck chassis was a complete no no. BUT that might be a UK or European thing. I am not a welder or certified spanner juggler and you guys seem quite happy with what you are doing so dont mind me.
It is not good in the US either , BUT I think that if you are only welding to the the complete rear of the frame it shouldnt hurt as long as it is behind the mounts for the suspension and axles , all of our trucks have welded plates and bolted hitches I have seen guys weld hitches on , they spend more time cutting and grinding to replace a hitch , they could have just made a new plate all together
High tensile frames have a sticker that says do not weld, however there are approved exceptions and one is welding to the end of the rails for trailer hitches. I know of at least one frame failure from welding a bracket to the edge of the frame flange just behind the cab of a truck. Bracket was for air dryer. Crack started right at edge of weld and progressed around the frame channel until frame collapsed.
AtlasRob I understood that welding on/to a truck chassis was a complete no no. BUT that might be a UK or European thing. I am not a welder or certified spanner juggler and you guys seem quite happy with what you are doing so dont mind me. Help the guy out and explain the alternative or the European way- perhaps it is a better method than what we have been using.
Not all dump trucks have pintle hooks but most construction cons ruction co. have at least one that does. I might also add that I have never seen a frame less dump body installed without welding angle hinge assy. across rear of frame
There are not to many places on a truck frame that I have not welded at some point in time.Sometimes in the winter I will do a Frame stretch on a truck for a customer.I cut it in half about 3 to 5 feet behined the cab on a road tractor.Weld in the new frame,add crossmembers,double frame.They do this so they can install a dump bed on it.You have to like drilling holes and welding if your going to do it.
I wish I had the experience and knowledge but sadly I dont. It is one of those little bits of ( maybe mis- information) information that seems to jangle a bell in my head. The only thing I can assume is that it causes stress as highlighted in a previous post. The alternative I would have to assume is to bolt only. BUT....... as also commented it is maybe ok if rear of the axles. :drinkup
That is not much help give a few details- I am always interested in a better way. How much do they allow you to pull with a pintle hook ? Do they use body bound bolts ? how many per side ? Does the OEM provide a mount ? Are you able to alter your trucks ? Over the years we have had trouble with trks that have "Cherry Pickers " such as logging trks - cracking the frame where they were bolted on to the frame- some still under warranty- would you leave cracks scrap, what?
I've been reading a little from the DOT sites. Hard to understand but BETWEEN AXLES any mod to frame flanges is expressly forbidden. Drilling main frame members OK, really no mention of welding I could find but I'm sure welding hardened frame is big no no. At the ends of the frame, front or back, welding and modifications are allowed if OK with truck manufacturer.
I am sorry but I am not qualified to take this further. All I am saying is what I have picked up over the years. I do not and have not done this sort of alterations / additions to trucks. :drinkup
Modular Tailboard Query I know this is an old forum but figured it worth a go. Would the idea of modular professionally manufactured tailboards appeal? Consider the following - Easy to order, Kit form so easy to fit, ability to trace product origin, simple repeat order for fleet harmony, strength assurance, insurance company ticks off, bolt to chassis (no welding to chassis), bolt only (no welding of hook), concise rating plate, precise details of vehicle towing capability in the form of a paper report.
If your thinking about geting into makeing and selling them i think some people would buy them and some would build their own. But in order to find out it may cost a million dollars to find out. I have 2 friends that are inventers that have come up with several good ideals but it has taken years to get it to the point were their ideas are on the market and being sold.You sound like you want to spend several 100.000 on testing and insurance.