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Old 12-26-2013, 08:24 PM   #29
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Originally Posted by mbass777 View Post
truck and rv togheter front truck weight 3980lb rear truck weight 10780lb and rv tire weight 8860lb gross 23620lb them dropped the rv and reweighed the truck stering axle 4020lb drive axle 3040lb
mbass777, I overlooked this earlier post of yours, you have the needed numbers.
This tell me that:
Your truck weighs 7,060 pounds
Your fifth weighs 16,560 pounds
Your pin weight is 7,740 pounds
This sucker is front heavy, not well balanced, almost 50-50.
From the weight it looks like your truck is a one ton, they weigh between 7-8,000 pounds, but the weight you have on its rears almost 11,000 pounds (5 1/2 tons) would give me a pause. As I wrote above I had a "brick movement moment" with over 8,000.
Can you pull an "unbalanced" rig like that, sure you can, but it better be an MDT or HDT.
Pin weight of 7,740 pounds is a lot of pin weight, you will tear apart all of the air hitches on the market with exception of one. Send me a PM or get hold of me and I will tell you which one.

I don't know why they built your rig like that, because here's another example.

45 feet long, 29,000 pounds, with 3 axles "way back there" and yet it was balanced so that pin weight was just over 6,000 pounds.

hjs
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Old 12-27-2013, 12:03 PM   #30
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What I have done is hook up and pull the 5'er to the scales, get weighed and pay, find a corner to park and unhitch the 5'er in the parking lot and reweigh the truck.
The scale weight convinced me to start looking for a HDT!
Am I missing something Jim?

For your pin weight wouldn't you still need your rv hitched up but its wheels off the scale or in the case of the cat scale exclude the weight on the rv wheels minus just the truck weight?

Just trying to understand this !
Thanks!
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Old 12-27-2013, 12:15 PM   #31
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That's what he said. But trailer doesn't have to be off the scale, just off the same platform the truck is on. CAT scales have 4 platforms with individual weights IIRC.
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Originally Posted by GLN View Post
Am I missing something Jim?

For your pin weight wouldn't you still need your rv hitched up but its wheels off the scale or in the case of the cat scale exclude the weight on the rv wheels minus just the truck weight?

Just trying to understand this !
Thanks!
Did my reply help?
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Old 12-27-2013, 02:02 PM   #32
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Here's a CAT scales primer. How to Weigh on a CAT Scale - YouTube
9 minutes well spent, will answer all the questions.

hjs
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Old 12-27-2013, 06:30 PM   #33
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The video primer pretty much covers it.
You take your empty truck rear axle weight and subtract it from your hitched rear axle weight. You have to unhook the camper to get this. If your landing legs are far enough aft on a seperate platform that you could unhook I guess you could unhook on the scale. Keep in mind though that alot of truckers use these and don't need to be kept waiting.
On my personal rig, I'm carrying 5200 pin, plus 3800 accessory pounds on my rear axle. More than I'm comfortable with. We scaled close to 28k.
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Old 12-27-2013, 10:39 PM   #34
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The video primer pretty much covers it.
You take your empty truck rear axle weight and subtract it from your hitched rear axle weight. You have to unhook the camper to get this. If your landing legs are far enough aft on a seperate platform that you could unhook I guess you could unhook on the scale. Keep in mind though that alot of truckers use these and don't need to be kept waiting.
On my personal rig, I'm carrying 5200 pin, plus 3800 accessory pounds on my rear axle. More than I'm comfortable with. We scaled close to 28k.
Not completely true. Some pin weight may also be on front axle. You need to weight the truck, both axles with and with out the trailer. Then subtract the empt weight from the loaded weight, both axles and you would have the actual pin weight. Rear axle means nothing. Most pins set a few inches in front of the axle. Even a inch will make a difference. Try it and you will see. Landing gear weight does not equal pin weight either. It will be heavier, as its closer to the center of mass.
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Old 12-28-2013, 09:21 AM   #35
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Ok I quit, You know more about my rig than I do. Your right I'm wrong, Move on.....
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Old 12-28-2013, 04:16 PM   #36
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Not completely true. Some pin weight may also be on front axle. You need to weight the truck, both axles with and with out the trailer. Then subtract the empt weight from the loaded weight, both axles and you would have the actual pin weight. Rear axle means nothing. Most pins set a few inches in front of the axle. Even a inch will make a difference. Try it and you will see. Landing gear weight does not equal pin weight either. It will be heavier, as its closer to the center of mass.
rollondow, now, now, we must not get frustrated, the above statement is accurate, so let's figure it out. Having installed few fifth wheel hitches on few pickups, the "rule" for pin placement is not few but actually 1.5 to 2.0 inches max, forward of the rear axle. A typical one ton will have a wheelbase of 137 inches for a regular cab and 141 inches for a crew cab. From my high school and college physics I remember that this is a simple fulcrum calculation meaning that this forward hitch placement will transfer approximately 1 to 1.25 % of the pin weigh onto the front axle. Or roughly 30 pounds of the 3,000 pound pin weight, to 50 pounds of the 5,000 pound pin weight.
So to keep things "accurate" you need to offset that weight in the rear in your fifth. Gallon of water is 8.33 lbs, so by adding 4-5 gallons of water to your fresh water tank you could achieve equilibrium and negate the weight transfer issue. But remember that is only "accurate" at 60 degrees F, water density changes with temperature therefore you need to go to the tables and "recalculate" if you do your weighing at other temperatures.
Another option would be to do your "weight offsetting" by not draining your black water completely. But remember that the temperature vs. density characteristic still apllies (this being a form of modified water) and although dissolved #1 does not alter it's density, the dissolved solids of # 2 do, by about 1% (it's heavier). And even that 1% will vary depending on your sewerage engineering knowledge and practical skills. This introduces too many variables, therefore I would suggest that you utilize pure water at outside temperature of 60 degrees to do your CAT weighing "and being accurate".

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Old 12-28-2013, 06:32 PM   #37
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HJS

KSCRUDE, I have owned (3) 1 ton trucks, a 98 Dodge dually Ext cab long bed, a 2002 Chevy dually crew cab long bed, and a 2011 Chevy with same, ALL of the trucks had a 20k Reese 5th wheel hitch installed to Reese specs and they were all centered over the rear axle. When weighing the rigs the front axle was never more than a few lbs different hitched up or not. Basically all the weight went on the rear axle.

HJS has the info you need hitch wise for that Semi to tow the Teton with, just give him a call or email and you will be good to go.
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Old 12-28-2013, 07:45 PM   #38
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HJS
HJS has the info you need hitch wise for that Semi to tow the Teton with, just give him a call or email and you will be good to go.
Vette Racer, we have spoken at length, "we have a plan".
Incidentally, on HDTs no hitch goes in front of the rear axle, they can be as far as 5 feet back behind the axle. And yes, this lightens the front axle by quite a bit, which at 11,000 lbs is a good thing. HDT are front heavy and close to the max of the front tires.

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Old 12-28-2013, 10:29 PM   #39
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Vette Racer, we have spoken at length, "we have a plan".
Incidentally, on HDTs no hitch goes in front of the rear axle, they can be as far as 5 feet back behind the axle. And yes, this lightens the front axle by quite a bit, which at 11,000 lbs is a good thing. HDT are front heavy and close to the max of the front tires.

hjs
Good deal Henry, yes, I know about the HDT deal, I was talking about the post concerning the LDT trucks and the hitch position. Glad you have it under control, with that much pin weight you ARE the person to go to.

Happy New Year!
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Old 12-29-2013, 10:28 AM   #40
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Good deal Henry, yes, I know about the HDT deal, I was talking about the post concerning the LDT trucks and the hitch position. Glad you have it under control, with that much pin weight you ARE the person to go to.

Happy New Year!
Ah, I see Tom. From my phone discussion with the owner of that Teton it is obvious that his fifth is "different" and really not suitable to be pulled with a pickup or a conventional air hitch, but as I said "we have a plan".
As far as setting up truck for pulling I have "some experience". I owned (and pulled) with four pickups, two MDTs and now an HDT and have been involved with scores of HDTs which now run with an ET hitch.
As a result (and also being too old) I don't get excited too often anymore.
But as you can see from my "technical post" above, I do get amused when too much "philosophy" or "theory" is beginning to take root and trumps common sense.
On a serious note, setting up pickups for pulling has become more critical as the pin weights keep climbing. My first fifth, bought in early 80's was 32 feet, weighed 8,000 lbs and had a pin weight of around 2,000 lbs. The hitch point was 2 inches forward of the axle, but frankly with that pin weight it didn't really matter where it was, even a couple of inches behind.
With today's pin weights climbing into the 4-5,000 pound region things are more dicey, with the pin point being positioned either neutral (right over the axle), or no more than 1-2 inches forward. Under no circumstances is it positioned behind the axle, it would create a very unstable truck with an off loaded front axle giving it that "floaty" feeling when steering (under-steer).
I don't condemn pickups. Modern pickups are fantastic vehicles with tremendous capabilities and they can safely pull 10's of 1,000's RVs of all sorts and sizes. Things get dicey when folks start pushing the envelope with very large rigs behind pickups. That's when you get into "theories", "philosophy" and eventually pig pigheadedness, "I know I can do it!"
Yes, you can jump out of an airplane with a parachute, just make sure you know when and how to pull that ripcord.

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Old 12-29-2013, 11:41 AM   #41
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Ok, While none of the OP's weights and measurements concern me, and I haven't posted my scale tickets, or posted any of my truck specs, hitch, or any other crucial numbers relevant to my situation, I gave my opinion of how the OP could easily weigh his rig at a scale with minimal fuss. Where my hitch sits, if my front end is loaded or not, has no bearing on the OP's original question of "Who makes a hitch that can handle an 8K pin weight."
I only answered because at 4500-5200lbs of pin weight I too am interested in a better hitch.
Hjsdds has been gracious enough with his time and experience to educate us in what is a very small circle of "Experts" in the heavy hauling rv world.

Now on my truck, moving my hitch 1.5 inches forward of the rear axle loads my front axle by approximately 250lbs. Which puts me at or just slightly over my front axle capabilities. BUT, doing so reduces my turning "cut" to less than 70* because of the shape of my 5'er's front cap, and fact that I have a short bed. Moving 4500 pounds to a position behind the rear axle would indeed make a dangerous driving situation.
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Old 12-29-2013, 12:40 PM   #42
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...............I only answered because at 4500-5200lbs of pin weight I too am interested in a better hitch................
An air hitch specifically designed for heavy trailers and heavy pin weights is available in two versions, one to go into an HDT and on to go on an MDT. Unfortunately because of it's configuration and weight neither can be installed in a typical pickup. Because of the forum rules I have to thread lightly on the subject.

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