CAT Scale Weights: Is My Truck and Montana Overweight?

[Mikendebbie]

Am I over-weight using these weights from CAT scale of the truck+Montana and the truck alone?
Comparative numbers are shown from a CAT scale weighing we did in July 2019, but I did not weigh the truck alone at that time.
The other "truck alone" weight was done in 2021.

Also - while I sitting on "level" concrete pavement yesterday - I measured the rig beltline to pavement to check whether or not the rig is running level...see screen shot. Ignore the "crowned pavement" in this photo...look at the dimensions. Measurements were about the same on both sides of the rig.

 

[LeftOverParts]

What was your fuel level in the truck?

Besides your new springs and hanger cross supports, was the trailer loaded about the same between the two times - food, gear, toys, black/gray/fresh, etc?

Asking bc it might be hard to make sense trying to compare the older weights with the most recent since you don’t have apples-to-apples. (It does seem strange though). Maybe just trust the most recent. I calc the pin to be 3600 lbs so the trailer is 3600 lbs + 12700 lbs = 16,300 lbs. What’s your trailer GWVR?

 

[Mikendebbie]

Yes - not apples to apples.
I received correspondence from Roadmaster asking for this information. I sent them the attached pdf. I will call one of the Roadmaster guys later this afternoon or tomorrow to discuss. Yesterday as I drove to the CAT scale about 15 miles away, I paid more attention to the (wife's description) RODEO BUCKING. I think the movement is more of a surge - front to back...lots of it. We do not remember feeling it that much before Roadmaster Comfort Ride was installed.

Gas tank was full.
My wife and dogs were not able to come along to the nearest CAT scales, but they were present in the 2019 weights.
The Montana was basically empty yesterday...black and gray tanks empty, no clothes or food in the pantry or fridge. To compensate for the "emptiness" - I added concrete blocks on boxes...+70 lbs in front of the fridge (to represent food in the fridge and the pantry) and 70 lbs at door to the front bath (to represent missing clothes).

Also we bought a portable AC last year to help with summer heat at the TX coast. It weighs 70 lbs and I strap it to the island during travel. In 2019 we did not have the splendide washer and dryer...add 60 lbs. I now carry a Craftsman pancake air compressor in the basement...add 30 lbs. A Blackstone portable propane grill - add 26 lbs. We probably got rid of some weight when we trashed our peeling theater chairs in favor of two swivel rockers + two ottomans. I chopped up the pitiful OEM table chairs for kindling (the match-stick pine broke, I repaired several times - finally cut them up) and we use two "stools" that look more like an ottoman than a chair. That swap was a weight loss - but no idea how to quantify it.

I will try to paste the images from the pdf - that will make it easier to read.

 

[LeftOverParts]

So GWVR is 16,845 lbs and you’re at 16,300 lbs. So 545 lbs left.

I’m no expert but I’d guess you’d want 4000 lb springs. (Assuming you max the trailer with 545* lbs more weight and allowing 15% extra spring capacity would be 12,700+425*/4/0.85 ~ 3860 lbs). Would be interesting what they installed and what Roadmaster says. Maybe different springs and/or shocks??? Wondering if slippers have a different curvature.

If the system doesn’t need to be changed, you might check that the truck shocks are still good.

*425 assumes 22% of 545 lbs goes on the pin (3600/16300=0.22).

 

[Mikendebbie]

Thanks! I like your math and that makes complete sense. When I bought the system I sent the weight numbers from 2019. so I think they would have come to the same conclusion. When I look at the invoice, the springs are identified as apart number only with no "LBS" designation or note. I sent an email to Roadmaster. I will find out tomorrow I suppose.

 

[Mikendebbie]

Answer from Roadmaster about my springs…

“5 Leaf springs are a 7k spring set. So, keep in mind we rate our springs in pairs so what you have are 3,500 lb each rated springs”

Another comment from Roadmaster…

“Typically when someone tells me they have excessive chucking and everything is right on their suspension they have a front living room or front bathroom unit. With this layout its common not to have enough tongue weight. It appears your 5th wheel has what they call a Rino pinbox (pin box is pushed further forward on the 5th wheel). Anyways, have you tried putting more weight towards the front of your 5th wheel?”

1. Questions to the forum…do you agree with “chucking goes with front living/front bath models”?
2. “Rino pin box pushed forward”??? OEM Lippert Road Armor 21k ??? Does that qualify as a “pushed forward pin box”? FORWARD of what? Edit: see pic below…this is a FORWARD pin box???
3. More weight to the rear…maybe i could change my ways and travel with a full load of fresh water. There is nowhere in my rig to put much weight toward the back. Nothing but small upper cabinets for paper goods, blankets, light bulbs. Im not going to put anything that weighs enough to make a difference in those cabinets. Looking for ideas to move weight to the rear. Edit: i always thought it was good that in my layout, heavy items were located over or close to the axles…pantry, fridge, washer-dryer.

 

[MandK]

Another comment from Roadmaster…

“It appears your 5th wheel has what they call a Rino pinbox (pin box is pushed further forward on the 5th wheel).

Research this. My Montana was a 1116 Lippert . I’ve not seen a Montana with a Rhino box. Not saying for sure, I just have always seen 1116.
I currently have a Rhino box on my sob and it doesn’t look like yours in the picture above.
Use this to identify what you have.

https://lci-support-doc.s3.amazonaws.com/quickreferences/qr-axles/ccd-0010092.pdf

 

[LeftOverParts]

If I’m understanding correctly, it seems the Roadmaster rep has made contradictory statements.

With this layout its common not to have enough tongue weight.

a Rino pinbox (pin box is pushed further forward on the 5th wheel).

Re adding tongue weight, there’s a seesaw effect from the trailer but I think adding pin weight mainly changes how the suspension at the truck reacts. (At the truck meaning just the truck or if you go with a flexible (sprung) pin, then the truck/flexible pin combo). Re the Rhino box moving the pin forward, assuming the rep means the pin-to-trailer wheel dimension is longer for your trailer, if he is saying it needs to be shorter for less chucking, that’s like moving the wheels forward which would imply the pin would get lighter?

Anyway, seems adding weight to one or both ends would be a good test but consider only changing one thing at a time. Maybe: Top off fresh to avoid sloshing and see what happens on say, the same 15 mile road. Then drain it. Then for a heavier pin test you could add weight to the back of the truck (have the kid at Home Depot load 300? lbs of sand bags behind the hitch) and do the same drive. You could instead fill the front waste tanks - easier, but maybe not a good idea. (Might need DW, dogs + the x lbs in the bed).

Saw your post on flexible pins. Maybe do the tests first to better understand what seems to make the ride better.

You might also check several AI responses with a query like, “what causes excessive chucking in a truck and 5th wheel combo”.

 

[RMcNeal]

Maybe it's the angle of the photo or an optical illusion, but your pin box does appear considerably more forward than mine. On my rig, the entire pin box is well beneath the overhang. It appears yours is right at the front edge?
Adding fresh water will likely reduce your pin weight as the fresh tank is in the rear and the extra weight behind the wheels will counterbalance to the back.

 

[Mikendebbie]

That photo was taken in 2018 at the Whataburger in Athens TX and has been screen shotted and copied by me so many times i never know where the original pic is…anyway, dont trust the ground in the image looking curved (i just used a screen shot to put the dimensions on it). Below are pics i took in the truck parking area when i was taking measurements. The concrete pavement at the truck stop was “flat” but it was sloped for drainage…i measured from top of belt line to top of pavement.

Based on my measurements - am i riding level enough?

I plan to fill the fresh water for our next trip and see if it helps.

 

[RMcNeal]

Gotcha. I can't imagine that the pin box would be that much further forward than mine. On your truck it looks normal in the above photos.

 

[Mikendebbie]

This photo shows the position of my hitch basically centered over the axle.
(Edit: this is without the pivot-head king pin jaws installed)

 

[Mark77]

Late to the party here but I have never seen a problem with added pin box weight (within reason) causing any problems, however not enough weight (usually on "bumper hitch" trailers can be catastrophic.

I am not sure I have ever experienced "chucking" with any of the 6 fifth wheel rigs Is have owned, but I have always been right at or heavy, current rig is about 800# over weight for my truck on the pin box as I tow a 36' trailer with a 2500. Towed thousands of miles like this and never had an issue with anything. Maybe settling the truck out like I do is why this "chucking" does not happen to me?

In summary, I would shift as much weight forward as you can reasonably and see if it makes any difference.