Truck frame rail extension

I haven't responded much after asking you if you could acquire some rail matching your current frame.
I'm still waffling around at a good solution.
Some truck frames do flex some are actually designed to be very limited in that nature.
Question: I've tried to tell from the pictures but cannot. At the crossmembers are the frame braces continuous and stamped shapes for the most part? Or are the terminated by a cast section that attaches to the frame and to the separate crossmember?

If it's the first those generally do twist some. To what extent depends on location and suspension type.
Of its the latter you have a style frame that is designed to be very rigid and doesn't twist along its length as much. If it did the cast sections won't hold up.

I cannot remember or tell what maker of chassis you have. Freightliner vs. Kenworth vs. Mack. They all approach them differently.

Kenworth and Mack tend to build very rigid.
A Kenworth I remounted a very large body on had cast brackets. The crazy part was they where aluminum. Definitely rigid and it was not designed to flex in a twist much.
This is also true of most all modern chassis. Suspension is much better as are drive train support.
 
Back to the price. Was that just a hitch mount? Or was it a frame with hitch and frame for future boxes, deck, and structure......or a turn key bed?
What other work did said SHOP do?
 
WARRIORWELDING said:
I haven't responded much after asking you if you could acquire some rail matching your current frame.
I'm still waffling around at a good solution.
Some truck frames do flex some are actually designed to be very limited in that nature.
Question: I've tried to tell from the pictures but cannot. At the crossmembers are the frame braces continuous and stamped shapes for the most part? Or are the terminated by a cast section that attaches to the frame and to the separate crossmember?

If it's the first those generally do twist some. To what extent depends on location and suspension type.
Of its the latter you have a style frame that is designed to be very rigid and doesn't twist along its length as much. If it did the cast sections won't hold up.

I cannot remember or tell what maker of chassis you have. Freightliner vs. Kenworth vs. Mack. They all approach them differently.

Kenworth and Mack tend to build very rigid.
A Kenworth I remounted a very large body on had cast brackets. The crazy part was they where aluminum. Definitely rigid and it was not designed to flex in a twist much.
This is also true of most all modern chassis. Suspension is much better as are drive train support.
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I didn't want to bug you as I know you said you're busy. Really hoping to have you do it even if I have to wait for you to work it in.

There are 3 crossmembers behind the cab. 1st one from the sleeper is 3 piece and has aluminum frame mounts and aluminum middle section. I actually had to buy those 2 frame mounts as they were extremely corroded. The two rear crossmembers are 3 piece also but the frame mounts are steel and the center piece is aluminum.

And it is a peterbilt 379
 
WARRIORWELDING said:
Back to the price. Was that just a hitch mount? Or was it a frame with hitch and frame for future boxes, deck, and structure......or a turn key bed?
What other work did said SHOP do?
Click to expand...
That price was for extending the frame, adding a pintle plate and mounting my hitch into the extension.

It was Becks spring shop in kernersville, they do all kinds of stuff from regular maintenance to inframes and frame work in trucks.
 
YotaOnRocks said:
That price was for extending the frame, adding a pintle plate and mounting my hitch into the extension.

It was Becks spring shop in kernersville, they do all kinds of stuff from regular maintenance to inframes and frame work in trucks.
Click to expand...
At probably 100 to 125 an hour.....parts, taxes, and the unknown........your quote was not exactly bonkers.

They are and anyone else is excepting a lot of liabilty. The transformation of the frame and the load points are well out side of the original designs intent. Your gonna pay for a lot of chalk board work with most any truck shop. Some fab shops outside the normal routine charge for all the "think tank work", some estimate it in, and many just spit ball. The shop giving the high estimate may be another walk in the park for them and they know exactly what it takes to make it work and last. In that case the premium is knowledge and a good turn around.
Personally I don't ever spit ball. I have done estimates and done well or poorly.....learning curve. As for charging for all the thinking, I've done a bunch from a distance on this because it intrigues me. A lot of: "what ifs". This is why I asked about aquiring frame rail, and the crossmember configurations. The frustrating part is the lightbulb hasn't went off and I have not had time to come see it.

I need to come out see the stuff in person.
 
WARRIORWELDING said:
At probably 100 to 125 an hour.....parts, taxes, and the unknown........your quote was not exactly bonkers.

They are and anyone else is excepting a lot of liabilty. The transformation of the frame and the load points are well out side of the original designs intent. Your gonna pay for a lot of chalk board work with most any truck shop. Some fab shops outside the normal routine charge for all the "think tank work", some estimate it in, and many just spit ball. The shop giving the high estimate may be another walk in the park for them and they know exactly what it takes to make it work and last. In that case the premium is knowledge and a good turn around.
Personally I don't ever spit ball. I have done estimates and done well or poorly.....learning curve. As for charging for all the thinking, I've done a bunch from a distance on this because it intrigues me. A lot of: "what ifs". This is why I asked about aquiring frame rail, and the crossmember configurations. The frustrating part is the lightbulb hasn't went off and I have not had time to come see it.

I need to come out see the stuff in person.
Click to expand...
I'll gladly make my schedule work to accommodate you coming to look at it, or I can mount up the suspension leveling valve and drive it to you if it makes it easier.
 
Thought I would add a video from a company that does a majority of the installs of these hitches for the rv community incase it helps any.
 
braxton357 said:
Ha, I like that there's an "important: do not weld to frame!" Sticker right there next to it. Also looks like they just used regular hot rolled for the extension. I guess if it works and there aren't any failures...
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No failures that I've read of to date. Several of the trucks have been in some pretty serious wrecks over the years and the hitches have stayed together and in the frame.
 
And for anyone interested in reading I'll add a link to a post from Henry Schmidt (Pheonix2013 is his username) about his experience in installing these hitches. He designed the hitch and built them up until about 2 years ago when it became too much and he sold to pop up hitch.
 
That post is an extension he did on a truck that was being built for the same general use as mine.

I'm in no way discrediting the knowledge/experience of y'all or saying that I'm right or Henry is right, I just wanted to share some more info for those interested from a source that has many years of experience doing exactly what I'm trying.
 
My 2017 Ram 5500 cab and chassis actually has a section on welding to the frame and where to avoid. I think it really comes down to CYA and intended use. The cab and chassis trucks are intended to be upfitted, and they know people will be welding on them, so might as well help them do it right. @WARRIORWELDING brought up some really good points about frame flex. At the end of the day, they all flex, its just a matter of where and how much. The backend of my truck can probably allow one side to articulate 6" and never move the spring or shock. But put a couple tons in the bed, or a piece of equipment and trailer behind it, and it's as planted as you could wish for.
 
Got some pics from @WARRIORWELDING today. I can't wait to see it in person, the work Andrew has performed is top notch.
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paradisePWoffrd said:
There are alot of bolts there for someone with "Welding" in their name. :flipoff2: Drew's work looks awesome as usual.
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To a point I agree. I also cannot stand things that are not modular or to a point serviceable. I reckon he gets tired of this rig it all can be moved to another unit. (Sorta my pre planning for him)

I refuse to weld flat beds directly to a frame most times for the same reason.

The rails are full bevel welded. They are made of a higher ksi steel to match the rails. Didn't have room to really tie a double rail in. Packaging everything behind the inframe shocks dictated how things went.

Lateral stiffness was the goal of the external rails and frame support. It has over 40 inches of frame extension aft of the original frame termination.
 
IMG_20220404_102142214_HDR.jpg

One of the fittings. The hitch is designed just narrow enough to require 1/4 shims on either side inside the rails.
IMG_20220404_102131450_HDR.jpg
Fitting the angle braces. Here you can see where the rear has a flange that bolts to the pintle plate. All of these are full bevel pen welded as well.
 
IMG_20220405_092941388_HDR.jpg
Putting the 1/2 by 2 inch band around the plate for the pintle. I choose to heat and wrap over splices and welds.
IMG_20220406_174514616_HDR.jpg
The perimeter is fully welded the back spaced a bit. The center is being laid out here. The reason is the gooseneck supplied by the hitch is literally a piece of channel laid flat and welded to the plate frame of the hitch. All well and good but I wasn't totally comfortable with that amount of support less then a inch and a half from the rear. I tied it to the pintle plate. No worries now.
 
IMG_20220414_170731952.jpg

Making the d-ring points. They are one inch thick and pass through the plate.

IMG_20220413_161957934.jpg
Matt wanted a specific height. But I allowed for raising and lowering the pintle just a bit.
 
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Here is the welding @paradisePWoffrd
IMG_20220414_152853144.jpg
I choose to box and brace over a really thick plate. You can see the d-rings coming through. The plates placed to tie in the frame points as well. The triangle kickers got three 3/4 bolts into the lower flange as well.

All in all a combination of Smaw and Gmaw was used on the whole depending on the nature of the joint and load it will see.

All the angled plates where tied in with multi pass 7018 stringers.
 
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