Hitch Pin weights question

[jbay]

I was looking for unloaded and loaded hitch pin weights of the 43 ft mobile suites, looking at the Naples floor plans.

Thanks for any help

John

[Cummins12V98]

Good luck with that! There are so many configurations those numbers will widely vary.

Our 39TKSB3 scaled from factory at 18,075# but in reality with Gen and "stuff" it weighs 23K with 5,500# pin.

[jbay]

So you are 23k on a 21k rated 5th wheel?

[Cummins12V98]

So you are 23k on a 21k rated 5th wheel?

That is correct!

[Maverick]

I was looking for unloaded and loaded hitch pin weights of the 43 ft mobile suites, looking at the Naples floor plans.

Thanks for any help

John


What year and what model?
The 2016 GVWR 23,000 on all the Mobile Suite 43 foot models. Elites are higher.
The Est. Dry Weight seems to be 19,500 on the Manhattan ( highest est weight)

You stated you wanted Hitch Pin Weights.

[jbay]

2015 naples

[Maverick]

On a 2016 43' Boston:
Hitch Weight: 3,200 lbs
Dry Weight: 19,700 lbs
Gross Weight: 23,000 lbs

I do not believe they changed that much. This should be close.

On DRV site the 2016 43' Naples
Hitch Weight:
Length 43' 4"
Est. Dry Weight 19,400 Lbs.
GVWR 23,000 Lbs.

20% calculations:
Est. Dry Weight 19,400 Lbs. x 20% = 3880 Lbs. Hitch Weight:
GVWR 23,000 Lbs x 20% = 4600 Lbs. Hitch Weight

Looks like DRV uses 16.5%

[jbay]

I agree i had guessed about 17% for pin weight. I am told the triple axles have lighter pin weights.

[Cummins12V98]

Take 25% of the RV Gross weight and you will have a close pin. Most EVERYTHING you add to the RV will directly go to the pin weight. The reality is MOST DRV's are over gross weight.

[jbay]

If 17% is the noted pin weight as listed by Maverick then wouldn't about that amount transfer to the lounge as I load it as long as I don't put a generator or bricks in the front in :)

[wingnut60]

25% of 23000 = 5750 for dual axles, right?
17% of 23000 = 3910 for triple axles, right?

[jbay]

Thats what I'm thinking, I have found lighter pin weights on the 43 ft and above models so far.

[Maverick]

At one time, a Suites Owner posted a spreadsheet.
The spreadsheet listed Dry Weight & Dry Pin Weights.
Units were 33’8” to 40’10” Mobile & Elite Suites

Here are the average results.
2011 = 22.07%
2012 = 23.27%
2013 = 23.43%
2014 = 23.44%

Look like DRV bases calculations on DRY WEIGHTS and not GVWR.

[Cummins12V98]

25% of 23000 = 5750 for dual axles, right?
17% of 23000 = 3910 for triple axles, right?

I think anyone thinking a fully loaded DRV of ANY length having 17% pin is in LA LA land! Comment NOT directed at anyone just my opinion.

[wingnut60]

Anyone here with an actual triple axle model pin weight?

Cummins--
Didn't you say you were going to have the 3rd axle installed?

Joe

[GlennWest]

Well my Teton is 3 axles. Just shy of 21K. We carry a 6k pin. We are full time though so we tend to load on heavy side.

[wingnut60]

Glenn, sorry, should have said any 'with a DRV triple axle pin weight.'
Very interested in how they actually balance the axle/pin weights on these longer unit.
Joe

[Joezilla]

Glenn, sorry, should have said any 'with a DRV triple axle pin weight.'
Very interested in how they actually balance the axle/pin weights on these longer unit.
Joe

We never got a chance to get our unit weighed before loading it with all our stuff. If I get a chance, I will weigh it on the way back to Texas in April.

Joe

[Cummins12V98]

Anyone here with an actual triple axle model pin weight?

Cummins--
Didn't you say you were going to have the 3rd axle installed?

Joe

After speaking to MorRyde the third axle option is off the table. When I get back there we will decide what option is best.

[wingnut60]

Sorry to hear that.

[Cummins12V98]

Sorry to hear that.

I could have it done but there are other options like up sizing the rubber springs.

With adding the riser it will transfer some more weight to the truck so I will guess i will have around 4,250# on the tires that are rated for 4,800#.

[GordonsontheGo]

After reading Cummins' overweight condition, I feel better about my own. When I bought my 2016 MS 38 RSB3 I thought I would have about 3,000 lbs. of cargo capacity on the 19,000 lb. GVWR. However, when I took delivery, I found that the options I added (such as fiberglass roof, roof-mounted satellite dish, upgraded Elite shower and 4 AGM batteries) reduced my available cargo capacity to 1,925 lbs. On my first weighing I learned that I was 650 lbs over the GVWR. I still have plenty of cushion on the axle ratings. Fortunately I also have cushion on the weights of my RAM so I have begun redistributing some of the weight from my trailer to the truck cabin. In hindsight I should have been considering the weight impact of my options when I was doing the build sheet.

[GlennWest]

The DRV has a strong subframe. As long as axles/tires are within limits you should be good.

[Cummins12V98]

After reading Cummins' overweight condition, I feel better about my own. When I bought my 2016 MS 38 RSB3 I thought I would have about 3,000 lbs. of cargo capacity on the 19,000 lb. GVWR. However, when I took delivery, I found that the options I added (such as fiberglass roof, roof-mounted satellite dish, upgraded Elite shower and 4 AGM batteries) reduced my available cargo capacity to 1,925 lbs. On my first weighing I learned that I was 650 lbs over the GVWR. I still have plenty of cushion on the axle ratings. Fortunately I also have cushion on the weights of my RAM so I have begun redistributing some of the weight from my trailer to the truck cabin. In hindsight I should have been considering the weight impact of my options when I was doing the build sheet.

Your frame is NO different than one with a 21K rating. What kingpin box do you have? I assume you have 8K axles.

Load it up! it will be fine as Glen says.

Call DRV and ask them what would it have taken to have your RV 21K instead of 19. I would guess kingpin box, that is easily replaced.

[GordonsontheGo]

Yes, I have 8k axles. After redistributing some of the load, I suspect I'm only 200-300 lbs. over the 19,000 lb. GVWR. Since I'm good on the axle ratings, I think I'll just leave things alone.

[Cummins12V98]

What pin box do you have?

[GordonsontheGo]

We have a MORryde pin box.

[Cummins12V98]

We have a MORryde pin box.

You should look up the model number to see what the rating is. There is nothing else that could keep you from having a 21K rating.

[CALinSC]

We have a MORryde pin box.

Maybe you have an adjustable pin box. Here is a picture I took of a MORyde box at a RV show a couple of weeks ago.

It's important to remember that only a certified vehicle modifier or the vehicle manufacturer have the authority to increase the certified GVWR of your trailer.

http://www.irv2.com/attachments/photopost/data/1657/2016_Cardinal_3850RL_-_2.JPG

[oldbird]

I added the Mor/ryde pin box to mine and have 5 bolts per side. I have another hole I could put a bolt in. I personally don't see how that can increase your GVWR but what do I know. I'll fill those two holes and tell my wife to load her up! LOL

[Cummins12V98]

I added the Mor/ryde pin box to mine and have 5 bolts per side. I have another hole I could put a bolt in. I personally don't see how that can increase your GVWR but what do I know. I'll fill those two holes and tell my wife to load her up! LOL

It's all about clamping force, more bolts = more weight the hitch can pull. DRV's are all built basically the same so it's basically the pin box and axle quantity that makes up the RV weight rating. I could change out to a MorRyde pin box and have a 24K rating per the pic shown.

[oldbird]

I plan on adding those two bolts but I'm not sure if they should be grade 8 bolts or not. The original bolts do not look like grade 8 bolts, I guess in the back of my mind I am wondering if grade 8's are to brittle? If they call for grade 8 I'll change them all out. Heck, maybe the original bolts should not have been reused? I know on certain vehicle applications they say not to reuse some bolts because of a 'stretch' of the bolt under load conditions. IDK

http://www.5thwheelforums.com/attachments/photobucket/img_20464_0_80a0b56df0b5b4e38af1ce6a6afdef61.jpg (http://s1282.photobucket.com/user/oldbird1965/media/Mobile%20Uploads/1453660825_zpsphpxo4tv.jpg.html)

[Cummins12V98]

You should always use grade 8 bolts on an application like this. I changed out my 5/8" bolts to 3/4" frame bolts. The pin box had shifted so the air fill was touching the bottom of the overhang of the RV. The holes were punched 11/16" and that was too much slop so I drilled out as many as I could on each side to 3/4" so the bolts fit tight then tightened them to 200'# TQ.

http://i.imgur.com/1fJ2a3Pl.jpg
http://i.imgur.com/x5PwQHjl.jpg

[terry and jo]

I think the markings on the head of the bolt indicate what grade they are. Back in the '80's, I managed a country grain elevator, and they built a new 150,000 bushel grain bin. After we got the thing full, it collapsed. Come to find out, the manufacturer of the bin sent grade 5 bolts instead of grade 8.

Since it has been that long, my memory is a little "loose," but I think the grade 5 bolts had three marks on the head and the grade 8 bolts had 5 marks on the head. Why I'm "loose" on that memory is that it looks like the bolts in Cummin's picture have six marks.

When looking at bolts in the hardware store, you might check the "marks" to see if I'm even close to right. I just went out to look at our Trail-Air pin box and it has six bolts with just 3 marks on the head.

Terry

[wingnut60]

I believe Grade 8 bolts are marked with the 6 dashes, as seen in Cummins' pics. This is the bolt used on my B&W hitch also.
I like to err on the side of overkill when working with a lot of weight, so use the G8 bolts whenever I think I need them.
However, I also would think both the strength of the bolts and the contact area between the pin box and trailer box would come into play when trying to determine the capacity of the connection between the pin and trailer boxes, plus several other minor items such as the tensile/crush strength of the metal surfaces.
We need an engineer to analyze this for us...
Joe

[oldbird]

I just looked at mine again. They have three dashes and the letters SJ. I think I'll replace all mine.

[wingnut60]

Probably isn't just this simple, but...

Grade 2 bolts------no markings----yield 55k psi tensile 74k psi
Grade 5 bolts------3 radial lines---yield 92k tensile 120k
Grade 8 bolts------6 radial lines---yield 130k tensile 150k

I think you are fine with the ones you have...

Joe

[GlennWest]

I weld at plants for a living. All the structure beams are connected with grade 5 bolts. 3/4" as a matter of fact. Never seen a grade 8 bolt on job. jfyi.

[Maverick]

This is what I have gathered from all the DRV Brochures that I saved.
These are from DRV Brochures. I only averaged the numbers.
It looks like DRV bases all calculations on dry weight. That is how these are averaged.

2 Axle % 2003 Average
21.19% 2004 Average
20.02% 2005 Average
22.17% 2006 Average
21.33% 2007 Average
0.00% 2008 Average
0.00% 2009 Average
0.00% 2010 Average
22.07% 2011 Average
23.37% 2012 Average
23.37% 2013 Average
23.37% 2014 Average
0.00% 2015 Average
0.00% 2016 Average