Welding Fifth Wheel Hitch installation

[Dkevdog]

OK- Time for some Gas on the campfire:-{} ... I know this has been discussed before, but since I now have a virgin truck I want to know more about Fifth wheel hitch installs. My 96 had the Drawtite 16K with the brackets being welded to the frame. I never had one bit of trouble with the setup, even though there were a number here who stronlgy disagreed with welding to the frame. I am taking the Hitch out of the old 96 and moving to my 2001, so I need to have the rails and brackets installed. At this point I am ready to have the welding done again, unless I can find a real good reason not to. Should I bolt it, or should I weld it? And why?



Looking for those with real world experiences. .



Kev

 

[Whitmore]

Kev,

Bolt it in, and make sure to use spacers between the bottom of the bed and the top of the frame !

DO NOT weld on the frame, it will remove the temper of the metal and you will have a weak spot there. JMO



cheers, Kevin

 

[RustyJC]

Kev,



Can you get the brackets to bolt the hitch to the frame? If you can, I would. Too much chance of having a heat-affected zone for me.



All my 5ver hitches (Reese and B&W) have been bolted to the frame. Your 2001 has holes in the frame for this purpose. If it were my truck, I would (and did) use them.



JM2CW... .



Rusty

 

[JTMcCracken]

Whitmore, you do not have a heat treated frame, you have a very weldable frame, they are welded every day, the hitch manufacturers have written instructions for welding on the frame. Old wives tales die hard around here. If you have it welded on you should contact Drawtite for the welding spec's and go to a good shop. As for a heat affected zone, if properly done the HAZ will exceed frame strength in every measurable way. JTMcC

 

[Whitmore]

I have sean the result of welded frames before, wives tale or not, I have responded as a fireman to many wrecks including head ons while pulling a trailer and the break or crack point of the frame is always right next to the weld, do what you want but I have sean enough to convince me that welding on a frame is not for me.

Just a month ago I saw a failure on a Reese 30K bolt in fail, it was not the hitch that failed but the installation, the idiot forgot to put the spacers between the frame and the box, that is the only bolt in application that I have ever sean fail... ... ..... all do to a shortcut.



cheers, Kevin

 

[pkennedy]

MR. McCracken is obviously a welder and knowledgable, the metal in your frame is not regular mild steel but is weldable due to the fact that your front 4 box mounts are welded to your frame. The important thing everybody gets confused on is Do Not weld or drill the flange yes it is OK to weld the web just like the factory mounts. Broken frames usually happen at HIGH stress points like when round bail pickers put all the weight on tail frame behind the rear spring mounts or excess weight directly in center of the frame while bottoming out springs continuosly on rough roads. When welded properly with 7018 rod the weld is good for 70,000 PSI and your frame max is about 40000 PSI max on an 11" D/W 350 cab & chassis frame. Frames always buckle in the flanges first so don't let them weld any closer than 1" from top or bottom on the web. If you are really worried get it done at a shop where tractor trailer frames are repaired or trucks are shortened or lengthened and decks etc. are installed and get them to sign work order by the certified welder. This way the shop and the welders liscence is on the line. Warning do not let automotive body shops do this task they are tin can benders and stretchers not certified welders. PK

 

[MidwestMotorman]

Don't let the welder paint your truck and don't let the painter weld the hitch in. Definitely find a certified shop that gives a work order signed by the welder. As a master certified bodyman, I will guarantee that the body shops only carry mild steel wire and rod. I would also keep the work order from the shop installing a bolt-on application as well.

 

[JTMcCracken]

nathanbush makes a very good point. Everyone on this site has a great interest in their truck, so I would expect someone having a hitch welded on would seek out an experienced shop (meaning one that routinely makes frame repairs and modifications) to do the deed. No one here would let the friend of their brother in laws uncle's boss change out the injection pump without checking that dudes credentials, I would expect the same for something as serious as mounting a heavy duty hitch. My company has stretched, shrunk, mounted semi wrecker underlifts and otherwise modified truck frames, both large and small, and I have the liability insurance reciepts to prove it. But to say that this frame can't be welded on is just flat wrong, good luck. JTMcC.

 

[pkennedy]

Thanks JT and Nathan for the re-enforcement that a job done properly done is not necessarily the cheapest or most convenient to us. Sorry Nathan did not mean to pick on a specific tradesman like yourself but in small towns like ours we have many small businesses doing multi-tasking to keep the bucks coming in. Unfortunately as you stated this information is forwarded in order to prevent incident and injury to us all in the form of a brotherhood CTD owners. The last thing anyone wants to see is a wreck, especially when it was caused by cheap fixes. Any good trades person should always happy to answer all your questions, down side to this is again D/C sees you the consumer going else where to get things done and profit going out the window. PK

 

[Dkevdog]

Well, thank you for the suggestions, the responses are what I figured to get. I was told, and was under the impression that properly welded hitch installation is just as strong if not stronger than being bolted in.



The shop that performed the work in my 96 is who I will have perform the work in my 2001. The majority of his installations are welded. He is a licensed/certified welder, and has been in business for more than 20 years. When I asked the installer about bolt in, he told me that he only does that if it is necessary, as is the case for the new 2003 trucks (in Dodge's case). The owner was going to get back to me with answers tomorrow.



Kev

 

[Casey Balvert]

Since it appears that we have some folks with metal expertise on this thread. Why do YOU think DC will not allow the new 2003 hydroformed frame to be welded or drilled for a fifth wheel hitch installation? I figured it was because the metal on the new frame was thinner than before but I am not expert on metal. Any informed opinions appreciated.



Cheers, Casey

 

[klenger]

This is a page from the drawtite installation manual. for my hitch. Notice the welding instructions at the bottom of the page. According to Drawtite, it can be done, but I don't see any need to. I installed mine using the bolts and had no problem.

 

[DHawthorne]

Everyone is right and no one is wrong. You really should not weld to it but if done right its OK. Now, here is something to consider.

If you weld it in, first find out what the tensile property is on the

frame, and the elongation, (flexibility/Stretch) Match the rod or wire under that tensile. If you use a filler that exceeds the tensile

of the frame and you have a crack develop, the frame will crack as opposed to the weld. If the weld cracks under stress for one of 20 reasons why welds fail, it might also crack into the frame.

You should always use the tensile of the thinest member to match

the rod or wire tensile and never do a full pen weldment in the frame unless you have a written procedure to follow and a qualified welder to that procedure.



On Jack up Drilling rigs the welds are designed to fail before the

main supporting member is cracked. This practice is common throughout the welding industry on things that count. Your frame

counts!



With a bolt in application you can remove the bolts annually and inspect them for stretch and deformity. With a fillet weld, all you can do is look it and hope you got penetration at the intersection of the two members. If the weld looks like peanut butter it most likely is.



Dave

 

[Oxjockey]

You should always use the tensile of the thinest member to match

the rod or wire tensile and never do a full pen weldment in the frame unless you have a written procedure to follow and a qualified welder to that procedure.

What he said. The frame will continue to flex, but the weld will be rigid, which will stress the frame right outside the welds.



I can weld, but I, personally, would probably mix bolts and welds. Maybe some 1" stitch welds would the outside. The thought of welding there doesn't really appeal to me - out of position overhead, verticle, fuel tank, etc. I'd also stitch to reduce the heat in the affected area.



Bryan

 

[JTMcCracken]

DHawthorn, designing welds to fail first is absolutely wrong, a properly made weld will beat the parent material and will be designed to do so in every case I have ever seen. Beat the parent material in all respects including elongation. This applies to structural steel, boilers & pressure vessels and high pressure piping. To use a weld as a fusible link is incredibly stupid.

Oxjocky, mixing bolts and welds in one joint is very dangerous and only legal on a structural weld if designed and stamped by an engineer, these are basics, you guys should stick with the recomendations of the hitch manufacturers. My apologies if you are a structural engineer and capable of running the numbers in order to design a welded and bolted joint, but I would still wonder why re-engineer a simple hitch installation. The hard work has been done for you and all you have to do is install as per the directions. JTMcC.

 

[pkennedy]

OK now you guys got me scared of welds on my frame afterall D/C has 4 welded box support brackets on their frame in which my 2500# camper will directly sit upon. Then you tell me these will not stretch at same rate as the rest of the frame even though D/C says I can haul it under warranty. On top of all this when I go up or over a curb my box and truck frame twists 3-4" by my cab and I can see that in my mirror. Then I was checking and greasing my front end only to discover that D/C has welded in the Spring towers and K member to the frame, holy crap I am going to get this under engineered junk heap traded tomorrow for a Kenworth. They only use machine bolts and huck bolts on their trucks, Man what was Dodge thinking. PS I already own the Kenworth Golly goin tohafta buy a Ferd/Chebby I know they would never do anything like this to a paying customer. PK

 

[Oxjockey]

pkennedy, the difference in this being I wouldn't trust MY welding skills (or lack of) or that of some other Joe Lackey in favor of something that's engineered, tested, certified, and robotically welded.



But you're right, noone should ever trust anything that's ever been welded.

 

[pkennedy]

Oxjockey you missed my whole point the factory has welded on the frame and warrantied it, we weld truck frames, vessels, 150 ton trailers and all of these flex and twist or expand. The point everybody seems to have missed here is there is prescribed procedures to do this and there are people with the training and skill to accomplish these procedures. If any body does not feel that a weld or there ability to weld is good enough on THEIR truck you dont have to mount things this way. We weld 5th wheels every day to bed trucks and special high capacity application tractors without failure or incident. The paranoia expressed on this thread about a weld process is unfounded, please people take a look at your truck and trailer and you will see that if you are pulling a 5th wheel (RV's included) that everything is welded. So the next thing you are going to say is no way the upper 5th on my fiver isn't and if you spend a little time looking at it the reason is not because a weld won't hold but to allow for height adjustment. Anybody out there got a tag along or a 5th wheel utility trailer with a bolted tongue assembly I dont believe so. The gentleman that claimed to see broken welds at accidents really did but what he probably doesn't see everyday is the unlimited amount of improperly mounted bolt secured reciever hitches, balls to recievers or the infamous farmer mounted ball on plate mounted to the pickup box. I do volunteer DOT checks up here occasionally and this kind of stuff goes up and down our highways every day and none of this seems to bother you as much as this topic. None of us that do work in these areas will say that under certain conditions that a weld never fails, however when you investigate vehicle accidents the failures amongst frame bolts and rivets are more than abundant all warranteed and engineered by the manufacturers. PK

 

[DHawthorne]

JT; Want I was refering to has to do with the structure not being destroyed when the weld fails. On Jack Up Drilling Rigs, a special grade of steel is used on the main supporting members that support the rig 70ft in the air. They are called cords.



At the lower end of the cords, there are large Top shaped objects which penetrate the mud up 70ft. These cans, as they are called, are attached to the cords with steel plates called, Shear Plates. These plates are welded to the Cord and the Can to get the can centered in the leg structure. The weld that holds the shear plate to the special steel cord is designed to fail and break away from the cord to prevent the main support member from cracking. If the crack were to extend into the leg member "cord"

the entire rig could fall.



The same priciple applies to welding to the frame on ones truck. I would want the weld to fail before it cracked into

my frame causing worse problems than

a failed weld.



If you need more info on this or choose to debate this further, please contact

me via e-mail since it appears this may become technical in nature and not useful to this seris of posts.



Dave

 

[TowPro]

Are you talking about the Spacers that go on top of the bed, between the bed and the hitch rail?



My 98 had to be drilled (as did my 96) and there are no spacer between the bottom of the bed and the top of the frame, if you are refering to the truck's frame.



the frame don't even really touch the bed, except in the locations of the bed mounts if I recall.



The reese uses "L" brackets that are bolted to the truck frame, and they are flush against the bottom of the bed, then a bolt passes from the top through the hitch rail, then a spacer that fills the gap where the truck bed is coragated, then the bed, then the "L" bracket, with a washer and nut below the "L" bracket.



I also added 2 bolts in each hitch rail through the middle, with large plates under the bed for extra protection. Sure there not going to take the weight of the 5er, but they can't hurt. (I always over engineer everything)

Originally posted by Whitmore

Kev,

Bolt it in, and make sure to use spacers between the bottom of the bed and the top of the frame !

DO NOT weld on the frame, it will remove the temper of the metal and you will have a weak spot there. JMO



cheers, Kevin