Air Bag Hitch vs. Solid Hitch

[RandyA]

 

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General Background:  Our Cedar Creek fiver had one of those Trail Air pin boxes with an airbag.  The hitch on the truck was a Reese without an airbag.  The combination worked good but the trailer I bought after the Cedar Creek fire only had a MorRyde slider pin box - no airbag.  I initially pulled the new trailer with a solid pin to hitch.  This was about 2,000 miles - mostly on Interstate.  Bridges and broken pavement were extremely hard on both the trailer and the truck.  I know the ride was rough because the covers on the lights in the trailer bedroom came off and all of the stuff in the bathroom cabinets was scattered.

Due to the good graces of fellow forum members, I was able to acquire a TSLB two airbag hitch.   It took a while to mount it on the Volvo and then pull an adequate number of miles to test the difference. 

I can unequivocally say that the difference was a significant improvement.  With approximately 3,800 pounds of pin weight, the airbag hitch has reduced the displacement of items in the fiver significantly.  It has also improved the ride in the Volvo as we are no longer thrown upward out of our seats when hitting the joints on most bridges.  The real test came when crossing a long bridge that supports had settled making the bridge surface like a multiple hump camel.  The up and down oscillations were dampened much more than my previous setup.

Anyway, solid hitches and pin box combinations on an HDT are definitely bad combinations.  I've run the test both ways and know the difference.  Air bags or air cells are a must.

[alan0043]

Hi Randy,

That is good to hear how the new hitch is working out for you. It's nice when a plan comes together.

Al

Edited August 6, 2018 by alan0043

[NDBirdman]

You brought up a good thread, so I'm going to hi-jack it for a moment if you don't mind Randy.

First, the RV is an older Fifth Avenue, 32 footer.  It will be with us one more year, then sold, will get a new(er), depends on the mood at the time, 36 footer.  The truck is a Ram 3500 DRW, short bed/mega cab.  It will most likely remain, love the truck.

Anywayz, pulled it to Indiana last month, passing though one state in particular that shall remain nameless.. (MN), I could not wait to get out of it!!  Even though the highway was pretty new concrete, every expansion joint threw us, so to speak.  It felt like we here in a high speed rocking chair though the whole state... very unpleasant.  Changing truck tire air pressures around made no difference, it would not stop!  RV has, at the time, brand new tires (high quality 16" Rib tires, not cheapies!!) and there is a shock (4) on both axles.  I am running an Anderson Ultimate hitch (goose-neck style).  The pin box is a Lippert, probably the same one the camper came with.

Ok, I'll get to my question.  Would a pin box with air bag smooth this out, or do I need a fifth wheel style hitch (air bagged?)?  Or do I need to put air bags over the truck springs?  I do understand the truck will never ride like a caddy, but it beat my wonderful wife to smithereens (did not do me any-good either....).  I had one guy that is a (5yr) fulltimer look at my truck and tell me the truck is too short, is the reason for the ride.  My truck has a 6ft bed, but with the mega cab, it still looks pretty long to me.  As a last resort, I would trade truck in on a new Ram with shorter club cab but long bed.  Any/all guidance will be greatly appreciated.   I have atleast one more year to get things right before my better half retires and we spend more time in the RV as snow birds.

[RandyA]

I'm sure other folks on this thread will comment.  Always expect disagreement - we are not scientists..... at least not some of us 😀

I've owned a variety of trucks and trailers and no two rode or performed the same.  The length of the truck wheelbase and the distance from the truck wheels to the trailer wheels can have a significant impact on ride comfort when hitting expansion joints on concrete highways.  Both chucking and alternating bouncing of each vehicle can make for an unhappy wife.  Those of us that pull with HDT's must deal with a rather unforgiving suspension designed for considerably higher pin weights than our fivers provide.  We also typically position our hitches aft of the rear axle - not over it like a PU requires.   I'm thankful for the airbags on our HDT cab and seats - features not common to PUs.  The HDT seats are also designed to minimize the jerk of chucking.  The use of an airbag connection at the hitch or pin box is an understood rule for an HDT conversion.  I was just sharing yet another first-hand experience as to the discomfort of not having an airbag hitch or pin box.  Basically confirming what we already know or believe.  I do know that even with a PU a solid hitch connection between the truck and trailer will transfer undesirable shock to both the truck and trailer.  I've been there and done that (never again!).  Adding an airbag pin box with a slide plate to reduce chucking is a common improvement option for fivers and pickup combinations.  Lippert sells one under the TrailAir name that does both.  With a short box that may be your only option.  I'm wondering where your ball is mounted for the gooseneck as most short beds require a slider hitch to center over the axle and keep from hitting the cab in tight turns.  Is your ball behind the axle?

When you get into the weight class like the fiver we switched to you generally move beyond the safety rating for airbag pin boxes which are typically designed for trailers in the 10K to 16K range and pin weights of 3,000# or less.  I have no experience with airbag hitches for gooseneck connections but have noted Hensley does make an adapter for their air ride hitches.  Perhaps Henry has one for the ET Junior as well.

I seriously doubt that adding airbags to your 3500 rear spring suspension will help.  In fact, they are more likely to make your situation worse.

I am sure you will get additional opinions and findings.  I hope you find a solution.

Edited August 6, 2018 by RandyA

[NDBirdman]

1 hour ago, RandyA said:

I'm wondering where your ball is mounted for the gooseneck as most short beds require a slider hitch to center over the axle and keep from hitting the cab in tight turns.  Is your ball behind the axle?

The truck ball in the bed is over the rear axle.  The hitch actually moves the trailer ball/pin connection behind the axle about 6 inches.  From what I understand, the hitch is designed to place the weight over the rear axle by way of design?  I can turn fairly short, but if I tried a 90, or maybe even 75 degree turn, I would blow out the rear window.  If I keep this truck and not get a longbed, I will probably get an automatic slider, dependent upon what RV we get down the road.  I will make sure to get an airbag pinbox on the next camper!  Or perhaps one for this camper next spring as winter is coming here quick and we are about done for the year.... I went and said it.... it comes quick up here....

[hone eagle]

I have been using a HDT for 7 years ,here is my opinion based on what I just replaced this spring .

The morryde pin box "spring" gave up, the bolt holes elongated and allowed the pin to move a couple of fractions of a inch, the back of the trailer swayed a foot.I replaced the spring but if it doesn't last It will be replaced by a solid pin box.

Also I remember Henry's statement "the air bag in a pin box is too small " the pin box dimensions restrict the air bag size and then require too much pressure to carry the weight,"they may as well be solid".

A air ride hitch on the other hand has 2 or 3 bags and they are bigger - much more 'squish'- better and best.

[RandyA]

I agree.  Isn't the MorRyde pin box spring a rubber shear spring rather than an airbag?  But just as a reference our old trailer was a Cedar Creek 14,700# max 34SATS.   Our pin weight was below 3,000#.  I did add the biggest available air bag for the pin box and double shocks on the pin box.  Dexter cushioned center points and working shocks on the trailer axles.  Reese 16K solid head hitch on the HDT without PU mounting legs or rails.  The airbag pin box worked OK with that weight class trailer.  Pulled OK with both my Volvo and GMC 3500 dually.  3500 series PU or HDT with a bigger trailer could be bad news with the pin box I had.  So, I went from old set-up to a 19,000# plus 40-footer.  Never got to try airbag pin box.  This trailer has MorRyde center point shear springs between axles.  17.5 wheels and tires at 121 psi.  Pin box is a MorRyde with a slider plate - no cushion.  Went up to 3,800# on the pin with no water.  Tanks are in front of the axle so if I add 100 gallons of potable water that is another 800#.  120 gallons of black and grey also up front - don't want to think about those full too.  Twin 40# LPG bottles and 5.5 Onan up front.  Also additional batteries - again up front.  I HAD to have the air ride hitch for safety and comfort.  Trailer pulls better than old one - always nice and straight.  The ride is also better.  I don't believe a heavy trailer will give good results with airbag pin box even if pin box "may" be rated for up to 22K.  BIG difference for us.

I revere Henry as the Moses of hitches and pin boxes. I know he does extensive research and development - great engineering mind!  I don't question what Henry says on hardware.  I have no doubt his assessment of air ride pin boxes is accurate.

Edited August 6, 2018 by RandyA
added material

[lockmup68]

comfort ride makes an aircell hitch for pickups. I think henry also has an ET model for pickups. I saw an add from hensley showing an air ride hitch for pickups. The air ride/cell hitch would make a big difference just as it does for HDTs. 

http://www.comfortridehitch.com/

http://ethitch.com/et-products/ (someone needs to tell Henry half his website is down/not responding)

http://www.trailersaver.com/our-products/