King Pin Boxes

[w4tl]

I recently purchased a new 2007 3400RL and so far have been pleased with the unit. Mine has the Lippert 1116 King Pin Box, which is considered to be a "medium length" pin box. The Lippert 1716 would be the "long length." My tow vehiche is a 2006 Ford F-250 Super Duty King Ranch Crew Cab SRW, Short Bed, 6.0 Power Stroke, 4x4 with the Reese 16K slider hitch.

I am considering going to a longer pin box either the Mor/Ryde or the Fifth Airborne RPB's. This would give me a more comfortable ride and also give me about 6 inches more space between the front of the trailer and the truck cab.

Any thoughts or experience with either of the above pin boxes and experience with any effects changing from a meduim length to a long pin box?

Any thoughts suggestions would be greatly appreciated.

Terry & Ruth Jones
Flowery Branch, GA

[Mrs. CountryGuy]

It is the opinion of Mrs. Countryguy and Countryguy, that to change to a long pin box might invoke troubles with frame flex, etc.

Go go a Rally, study the length of the pin boxes, where they are set on the units, and the length of the bedroom overhang. (Talking about Montana brands only, those covered in MOC)

You will note that the earlier models, have longer overhangs, bedrooms set towards the front, which results in at least 2/3 of the weight of that bedroom resting on the overhang. Later models, aka, yours, have shorter overhangs, bedrooms set in that area differently, resulting in half or less than half of the weight of the bedroom slide on the overhang.

We did this at Fall Rally 2006, and noted that between early models, specifically OURS, a early 2004, and later models, specifically SteveR's, think his is a 2006?? that there was considerable difference. Measured from the middle of the king pin to the front compartment door, and, sorry to say, I don't remember exact measurement, however, allowing for old brains that leak, ours was somewhere between 15 and 25 inches longer.

Our take, no engineers, no nothing other than our personal opinion and what common sense we have left (no smart remarks now, FRIENDS OF OURS!! ) THAT, they shortened the area up to reduce the stresses on the bedroom overhang area (those of you with front living rooms, this applies, only substitute LR for BR), and frame flex is also reduced.

If you are asking for an opinion, this is ours: STAY WITH THE PIN BOX LENGTH THAT CAME WITH YOUR UNIT. That is our opinion, and probably differs from many on the forum, that is what the forum is for, sharing of opinions.

[bsmeaton]

Terry,

Contradictory thoughts on this - My gut feel is that messing with the pin box length means messing with trouble regarding frame flex, however -

Many of the early 2007 3400RL units that had a GVWR of ~13,500 came factory with the Lippert 1621 Pin Box, which is nearly 5-1/2" longer in length than your 1116!! In addition, I have heard Lippert advise folks to look at the 1716 pin box as an alternative to the 1116 to gain length (here on MOC).

We installed a fifth airborne hitch replacement for the 1116 pin box on our 3400. With the install, we actually lost another 1-1/2" in length and it is real tight on the back of that Ford. I use my slider hitch now more than I ever did with the old Montana. In retrospect, I wish I would have stuck my neck out a little farther (so to speak) and looked at the longer pin box.

[MikeM]

Terry,

I agree that extending the pin box will put more stress on the frame due to the increased lever arm length. Whether or not that will result in long term damage is open to question, but after seeing previous posts about frame flex/damage in older units, I think I would error on the side of caution. You've got the same hitch as I do and when the slider is extended, it would be very difficult to contact the truck, in even tight turns.

As for the pin box, I've got about 10,000 miles using the 5th Airborne (based on a lot of posts on this forum) and I wouldn't be without it. There are better (read: more expensive) options, but if you're not full-timing, the Airborne or Mor-ryde is probably all you'll need. Keep in mind that the two are functionally different; the Mor-ryde is effective for only longitudinal shock but the Airborne dampens that plus vertical.

BTW - was good to see you at Field Day this year and hope we can do it again next year. Hello to Ruth.

Mike

[kerry]

If you are thinking about changing the king pin, check with Lipard, their # is on the king pin. They will tell you what you can and cannot do to avoid warrantee problems. Kerry

[stiles watson]

I will tell you what I know. The stress on my back demands greater attention than other stresses. We have just completed two days of towing in East Texas and Arkansas. Have been on some rough roads today. At the end of the day, I am sooooo glad we have the 5th Airborne pin box. The fatigue level is greatly reduced by the shock absorption of the 5th AB. My logic tells me that the shock absorption also has to reduce the pin stress.

[pud2]

We we ordered ours we had the short bed t.v. and wanted the long pin box. When unit came in it was the medium pin box. Dealer called the factory and they said they wouldn't put the long on because of the sress on frame.

[w4tl]

Thanks everyone for your input to my query. After reviewing the responses I did a little checking on my own. First I called Keystone (Montana) and they offered no help at all other than to say that they would not warrant anything at all if any modification was made including aftermarket king pins other that what was there when it left the factory.

I called Lippert who by the way makes both the frame and king pin box for the Montana's and would be the waranty point for issues regarding the same. They make a long pin box for this application, but it is only rated at 15K, the original 1116 pin box is rated at 19K by Lippert. What he did tell me was that they recommended the TrailAir pin box.

http://www.trailair.com/

This company is owned by Lippert. It was late in the day when I got this information and have not made contact with TrailAir yet. Their unit looks good and the price is in the range of the Fifth Airborne. Just wondering if anyone has had any experience with TrailAir? I was led to believe that the frame would still be warranted if I used a TrailAir pinbox. This statement was made by the rep I talked to at Lippert.

My problem is if I go with the Fifth Airborne I will loose another 1 1/2 inches of rear clearance due to the design of the Airborne hitch. I simply can't stand to loose absolutely anymore rear clearance due to the positioning of my Reese 16K slider. The king pin now rests approx 2" forward of the rear axle due to the positioning of the hitch brackets due to the suspension and 4x4 TV. (Ford 2006 F250 SD 4X4 King Ranch Crew Cab Off Road Package,etc.). All information is greatly appreciated.

Mike, on a side note it was great seeing you at FD also. I saw you as you were leaving town (985 & Friendship Road). We were leaving Camper City after picking up a tire that we had an issue with. Apparently the conract hauler for our 3400 had a flat during delivery and plugged it on the road. Unknowing to us or Camper City and of course it went flat on our first outing and thats when we didcovered what happened. They gave us a new tire as I did not want a plugged tire.

Keep the comments coming.

Thanks Terry & Ruth Jones
Flowery Branch, GA

[Countryfolks]

We have a TrailAir. We had a problem with it [broken weld] and they replaced the entire unit. No problems with the new one. I did some measuring when we had the first one installed and the pin is located approximately the same distance as the original Lippert supplied pin box. The 5th Airborne and the TrailAir are about the same design, the location of the shock and hinge point are reversed and I think they use different shocks.

Skip

[dsprik]

Any votes for the MOR/ryde pin box???

[exav8tr]

Dave, I ordered the Mor Ryde about two hours ago, will receive in about a week and install it then. I talked to several other with the mor ryde and they swear by it, of course so do all the other hitch owners with their particular brand. I just finished the Life on Wheels conference and the fellow teaching the brakes and suspension class has one and says it is the best bang for the buck AND he doesn't work for Mor Ryde either. He says the Mor Ryde does the same as the air ride hitch pins for less money. We will see about that in the next coming weeks.....

Phil

[Mrs. CountryGuy]

Way I understand:

morryde is superb at reducing porpoise situation.

air pins are not quite as good at that, but they also soften the bouce and wear and tear and stresses on that front overhang area.

we were as interested in protection of frame as we were stopping porpoise. Isolator is the predessor to the Fifth Airborne.

I don't believe the Morryde does the same as the air pins.

Someday would like to ride in a truck with 5er with Morryde on it to give it a try.

Did Trailaire ever come out with the air pin that was supposed to marry the best of Morryde and the Fifth airborne????

[skypilot]

I have TrailAir pinbox (unit came with it) and I have a bucking/chucking problem. MorRyde gets rid of this problem but not the up/down bounce of road bumps, etc... still feel them where the trailair gets rid / mitigates the severity of them. Neither one does both. Best solution I've read about (albeit very expensive) is the MorRyde pinbox with the TrailerSaver hitch (Note TrailerSaver hitch, not pin-box, this is the hitch that has the airbags for the up-down movement). As I recall, Orv has this hitch for this very reason (i.e. saving his trailer from the up/down shocks of todays roads).

[stiles watson]

What makes this so tough is that most of us get one shot at making the decision. There is not much of any way to test before buying. You buy, install, and hope you got it right.

I looked at the Mor/ryde and believe it would have helped over the OEM pin box. When I investigated the design characteristics of the 5th Airborne, I believed it would give better shock absorption for both vertical and horizontal stresses. My wife is the one with greater sensitivity to chucking and bouncing due to arthritis and osteoporosis. She has been very pleased with the results when using the 5th airborne.

Today was a good example of its effectiveness. In the 250+ miles covered, there were stretches of old concrete highways with a steady supply of the seams across the lane. We found the steady noise and and constant bump of each seam to be irritating, but not painful to her as in the past.

Nothing will take the jolt of a bad road completely out of your ride.Our expectation of reducing the severity of road shock has been met.

[Countryfolks]

I'm not sure I see any really significant difference in design principles between the TrailerSaver hitch, the 5th AirBorne pin box and the TrailAir pin box. The TrailerSaver hitch has 2 air bags vs the pin boxes 1 and no shock that I could see [similar to an upside down 5th AirBorne with a latch instead of a pin], otherwise they all hinge at one end and use an air bag[s], essentially, at the other. It seems, on the surface, they all would improve the ride about the same. I kinda think that the only real way to determine which was best for a particular use[r] would be to try each one, one right after the other, on the same road. Air Safe hitches are a different story, they use an air bag on each corner. They also cost more than the TrailerSaver hitch. The MorRide is essentially 2 steel plates bonded to an 1 1/2" or so of of elastomer with a pin on one side. They all meet the requirements of their users to a point.

Skip

[dsprik]

Stiles is exactly right. This can be a stressful decision - hoping you don't kick yourself down the road for making the wrong choice... Still leaning toward the MOr/ryde...

[sailer]

We have the pull-rite with no air bags but a great slider hitch on a 06 f250 king ranch and can make a uturn on the hiway with no problem ,, but no air bags but i don't feal as though we need them ,, maybe if i rode in a unit with 1 i could feal the dif john

[dsprik]

I'm thinking the MOR/ryde pin box combined with my Airlift air bags would work very well together, as the air bags handle the up and down jarring quite well.