Fifth wheel pin box extension

My old Terry had a square front and the pin was under the nose. I looked into extending the pin box but instead bought a SuperGlide. I have to make a pretty severe U turn (not 90* but close) in my culdesac to back into my driveway. The SuperGlide did its job and I cleared my cab by several inches. The front cap on my Arctic Fox has a bit of a curve to it but is still fairly square as compared to some of the units out there. However, the pin box is forward of the nose and clears the cab by a mile even in the tightest turns.

My FW came with an extended pin box and it works fine, but with a slider hitch it ran the pin box mounts into my tailgate. Works great with an Andersen flipped back with the adapter flipped forward, but you do need to make sure your clearance is good. I may have said a choice word or two when I dented up the tailgate of my brand new truck, but at least I got that first ding out of the way.

I bought a Pop Up pin extender, installed it and took the fiver for a ride. Imagine my surprise when I couldn't get out of the driveway. The added length made the pin box hit the side of my truck. Backed up, jacked up, removed extender and it sits on a shelve in the garage. $350 or so shot in the butt. Came from listening to all the people out ther that say you need to extend it or buy a slider or this or that. I have a 6-6.5 ft ? ft standard bed on a 2011 chev and can get so close to 90 I don't need anything. Pull with a Trailer Saver air hitch.

prk7 wrote:
Are there any drawbacks of adding a ten inch pin box extension to a montana 3791?

If you have a "standard" pin box, where the pin is literally under the front of the FW, Montana likely offered an extended pin box as an option. That being said, Montanas that are a few years old did have some frame issues, and almost all seemed to have factory-installed extended pin boxes.

ON EDIT: One of the reasons that I want to stay as close to 30' as I can, is to avoid having to make sharp turns like this. (That, and to avoid having to buy another truck to handle a bigger FW.) FWIW, the '02 D'max in my sig will NOT hit my very square-front Komfort at full lock, R or L; ALL will hit in reverse. A slider just gives you more room before you DO hit. :-)

Lyle

A longer pin box will not give you 90 deg. It will only give you a couple of more degrees. If you want to go 90 deg. you will have to get a slider hitch. Measure from the kingpin to the corner of your coach, then measure from the rear window of your truck to the center of the fifth wheel, then measure from where you feel a longer pin box would take you and you'll see what I mean, you don't gain much. 1/2 the width of your trailer has to be longer than the distance from your rear window to the fifth wheel to get 90 degrees, that's what a slider hitch gives you..

I'm of the opinion that 90 degrees between truck and fiver is unnecessary. Physics explains that at 90 you cannot move the fiver forward or back, just rotate it about it's center point putting great stress on the suspension, tires, etc. Instead a little extra jockeying back and forth should accomplish any parking need. The truck steering wheel can only turn a max of about 36 degrees so while making a 90 degree turn at full lock, max angle between truck and fiver will be about 45-50 degrees. Finally TT setups cannot jack-knife as sharp as a typical short bed and extended pin box setup. I've never had a problem in 25+ yrs.

To OP, the sidewinder puts less stress on the fiver frame than a longer extension. And the back of the pin box won't hit the tailgate or sides of the truck box.

I really believe that those of us who can, DO!

My current 5er with a slider won't go 90 before the square corner 5er hits my cab. But I have had 5ers before that would go 90 when needed.

One member said he has to do a 90 back in to get his 5er behind the garage. After unhooking he then jacked his trailer axles to relieve the stress.

Just because someone doesn't need to go 90 doesn't mean others don't.

Allworth wrote:
Turning 90 seems to be over-rated. How often do you do it? If you can do it, that will put terrible stress on the rear axle and tires as they slide sideways.

Why????

I really believe that those of us who can, DO!
Call me crazy but I turn 90 degrees quite often. I get in into non RV friendly fuel stations (less expensive fuel) and squeeze into spots I shouldn't be in. Turn 90 a lot in those situations. The last campground we visited, we were in a site that needed the 90 degree turning ability. This site put us right at the creek with beauty all around. "Worth it". To park the 5er here at home I also go a tad over 90. So yes, those of us who can, do!
I do remember when I had a manual slider with my old rig, I purposely avoided places I had turn 90 also.

prk7 wrote:
Are there any drawbacks of adding a ten inch pin box extension to a montana 3791?

Agree with MFL for best answer to your question.

Just something for you to chew on.........My 1st RV was a new 1984 Aljo which was years before the industry gave us a sliding hitch. The unit came with a 30" extended pin box for short bed trucks and or a zero extension pin box for long bed trucks.
Well my truck had a long bed and the Aljo came with the 30" box which left the front of the 5er about 8"-10" from the back of the bed. The trailer pulled like a lead sled it was back to far from the trucks cab to be aero.
The RV dealer was looking for a 30" box for a customer with a short bed truck so I swapped.
You wouldn't believe how much easier the trailer pulled in heads winds and side winds.

My son has a forty one core as well, he says I'll need ninety to get into some camp grounds, so far i haven't needed ninety.