Pin Box

[DReisinger]

Purchased an 05 Fifth wheel, it has an extended pin box. I have a long bed 3500 Cummins and don't really need the longer box. Would it be advantageous to replace with a straight down box, other than shorting entire rig by a couple feet.

[rhagfo]

This is the pin box on our current 5er!!



This is the pin box on our old 5er. The 5er was about 10" from the rear bumper, so close I thought it was going to hit the first time I towed it.

[ckwizard777]

It varies rig to rig.
You need to measure from the center of your hitch to the corner of your bed or bumper and then measure from the center of your king pin to the front of your rig to see if you have enough room for a straight pin.
With my long bed Chevy and my Montana I have about 4-inches to spare so yes it can be done but not all rigs are the same.
Now good luck locating a straight pin because I never have been able to find one.

[gparrow]

I don't think you want to do that, in addition to moving the chin foreword you will also be shifting the main floor part foreword. Decreasing that distance by any amount that would be of benefit to the pin box would probably cause your bumper to hit the bottom front of the fiver.

[bpounds]

Extended pinboxes have become pretty much the defacto standard these days. Don't recall the last time I've seen an RV without one. If your pin box is about flush with the front cap, I think you've got the standard pinbox for your rig. Yes, it does increase stress on the frame, but you get a larger basement storage area.

Unless you've got something different than I am imagining, such as a pin that is a foot past the front cap, just leave it as is. If that doesn't sound right, how about posting a pic?

This is ours. Not even considered an extended box these days, even though technically it is. I also have a long bed. I wouldn't even be able to hitch up with anything less. In the distance you can see the neighbors much larger rig, with a similar pinbox.

[johntank]

rhagfo; wrote
The real issue is the distance from the back of the cab to the pin location, if it is less than half the width of the 5er, then really hard to get close to a 90 degree turn.

As this is true on short bed trucks the other distance one needs to look at is the distance of pin to the vertical wall of the 5er and the distance from center of hitch plate and corner of truck bed. It is just my opinion that this distance is more critical than the cab to pin distance.

[rhagfo]

ckwizard777 wrote:
If you have a v-tailgate and dont need to open the gate while hitched then yes straight down is the best way to go as it will remove most of the stress off the pin box frame and most likely eliminate any chance of frame flex or breakage.
I never understood the whole extended pin box thing myself.

Extended pin boxes are for those that want to tow a 5er without a sliding hitch!

Puts the nose further back when turning with a SB, that and radically rounded fronts, means non slider SB towers, just need to turn a bit further to dent the cab and bust a rear window.

The real issue is the distance from the back of the cab to the pin location, if it is less than half the width of the 5er, then really hard to get close to a 90 degree turn.

Now we all get chopped up front closets because of it. we still enjoy a 8' wide flat floor in our 5er.

[ckwizard777]

If you have a v-tailgate and dont need to open the gate while hitched then yes straight down is the best way to go as it will remove most of the stress off the pin box frame and most likely eliminate any chance of frame flex or breakage.
I never understood the whole extended pin box thing myself.

[johntank]

DReisinger wrote:
Purchased an 05 Fifth wheel, it has an extended pin box. I have a long bed 3500 Cummins and don't really need the longer box. Would it be advantageous to replace with a straight down box, other than shorting entire rig by a couple feet.

Have you hooked up to this trailer to know for sure that you don't need the extended pin box?


I also have a long bed Dodge 3500 and 05 5er and need the extended pin, so I can turn without the corner of truck bed hitting trailer.

[Cummins12V98]

Enjoy the longer pin box! Most likely you can lower your tailgate and still walk between it and your RV when hitching. Also it may be a good location to install a hitch for a bike rack.