Jump to content

Hitch pin box


Tom'sRedwood38GK
 Share

Recommended Posts

I would like to pick everyone's brain for ideas about what to watch for when changing up the pin box on my 5er.  What I found out this week after finally getting the time hitch the truck to the 5er was it is to low to tow.  So I have found a fabricating shop that is willing to take on the task of building me a new pin box.  Questions are if I come straight down from the frame I can shorten up my total length almost 2 ft., will this be a problem for the frame on the 5er?  The total length from the center of the pin mount on the frame to the front of the trailer is 52 inches.  The total length from the center of the pin hitch to the corner of the truck is 41 inches.  If my common sense thinking is right that should leave me 11 inches from the corner of the truck to the front of the trailer.  Does this sound like the correct thinking?   The hitch on the truck cannot be raised without some major changes account it is all welded together.   Any help with these questions would be greatly appreciated and in advance thank you for your input. 

Edited by TomNGina
Link to comment
Share on other sites

No question a straight down pin box will have less stress on your frame than the silly long extensions that usually come on rv fifth wheels.  Coming from having race trailers where all the pin boxes are straight down, all these extended rv pinboxes always look like they would ruin the trailer frame.

Sounds like you plenty of clearance from the truck to the trailer to do it.  I am assuming you also have extra room between the front of the trailer and the back of the cab and/or any deck cargo?  It will also put a few hundred pounds of pin weight on the truck due to the shorter wheel base on the trailer, which will also make it just a little easier to maneuver backing.  All to the good.

 

Here is an article on different pin box configurations:

https://www.etrailer.com/faq-measuring-a-fifth-wheel-pin-box.aspx

You should be able to determine which "long" pin box you have and order the corresponding "short" style box to bolt right on without having to fabricate one.

clarification:  that article is to order a fifth airborne pin box, but the dimensions and oem part numbers are useful to find a straight down box.

Edited by Hot Rod
clarification
Link to comment
Share on other sites

The onset of the extended pin boxes is in large due to large number of people trying to pull 5ers with short box trucks.  By todays standards, out 5er has a short pin box.  There is an older 5er down the row from us that has a straight down box.  You cannot begin to tow with a short box truck.

The extended pin box will definitely put a lot more stress on the frame of the trailer.  Stick a goose neck adapter on it and the stress goes up on the area where the pin box attaches to the trailer frame.

 

Ken

Link to comment
Share on other sites

Thank you, everyone, or your thoughts and the reason that I need to custom make one is because the air hitch on the truck is a little low and I need to extend the pin box hitch to repair it right for the long term.  So yes I need at least 15 inches from the bottom to the third bolt hole for it to work around my situation with the air ride hitch.

Link to comment
Share on other sites

Howdy Tom,

I have done this a couple of times, if you have clearance between the trailer and the truck or cargo, GO FOR IT you won't be disappointed.

I tried to find the thread I started on doing this but my ability to FAIL at searching for anything is legendary, I made that thread about three years ago and I could only find threads I started within the last year, perhaps someone else would have better luck finding it, lots of photos showing every step of the process.

A couple of photos to show the difference between the extended pin box and the straight down one that I built.

What I started with.

DSCF0269-L.jpg

What I ended up with, two feet shorter over all and handled much better.

DSCF0321-L.jpg

Dave

Edited by mr. cob
added photos
Link to comment
Share on other sites

So I found a young man that is in the welding business that was willing to take this project on.  I can tell you that he has done an amazing job so far. We have some trimming on the back of the hitch to make it safer on the old noggin' should be done and picked up by Tuesday. Thank goodness I hung onto an old pin box from another 5th wheel I changed out for an air ride. We had the kingpin and plate all he had to do was cut it off the old hitch and build the box.  It is going to have extra holes so it can be adjusted up and down to the perfect height.

 

 

Pin box.jpg

Edited by TomNGina
Link to comment
Share on other sites

John,  I do believe that this is not all the way up into the frame just a quick view for my pleasure.   He placed some support across the back of the box also so I have a place to put my cords when parked. Then he is going to angle cut the lower rear of the box so the sharp point doesn't cause a health hazard to my head when going under the front compartment.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
×
  • Create New...