Community Forums

Crasher · 08-14-2015, 08:37 AM

If you want to do it right, a trip across a Cat scale is not enough. You need to get individual position weights to know if you are within tire and axle ratings. As example, when my coach was new, I noticed that the right front tire would increase in pressure faster than the front left. The TPMS indicated that. When the front axle was weighed, it was 15,300# and rated at 15,600#. That's just fine for the total axle weight. However, when the front tires were weighed separately, the front left was 7000# and the front right was 8300# which was 500# over the tire capacity rating. I figured out what the problem was and corrected it without moving any cargo. Now, after another mod, the front tires are within 150# of each other at 7300#. 500# below their capacity.

There is more to to it than running across a scale for a check if you want to be assured you are safe.

tbbg II · 08-15-2015, 04:21 AM

[QUOTE=Crasher;2696722] When the front axle was weighed, it was 15,300# and rated at 15,600#. That's just fine for the total axle weight. However, when the front tires were weighed separately, the front left was 7000# and the front right was 8300# which was 500# over the tire capacity rating. I figured out what the problem was and corrected it without moving any cargo. Now, after another mod, the front tires are within 150# of each other at 7300#. 500# below their capacity.
QUOTE]

Oh man, I gotta ask, if you didn't move anything how did you get nearly half a ton of weight off the front axle?

ahicks · 08-15-2015, 06:31 AM

Regarding coaches that are very near capacity when dry, my experience has been they were very nearly always gas. One of the DP's virtues is being built heavy enough to handle what people want to carry with them - and then some. That's also why they seem to handle stopping a little better... my opinion.

Crasher · 08-15-2015, 09:39 AM

[QUOTE=tbbg II;2697885]

Quote:

Originally Posted by Crasher

When the front axle was weighed, it was 15,300# and rated at 15,600#. That's just fine for the total axle weight. However, when the front tires were weighed separately, the front left was 7000# and the front right was 8300# which was 500# over the tire capacity rating. I figured out what the problem was and corrected it without moving any cargo. Now, after another mod, the front tires are within 150# of each other at 7300#. 500# below their capacity.
QUOTE]

Oh man, I gotta ask, if you didn't move anything how did you get nearly half a ton of weight off the front axle?

The uneven front tire weights was due to the LR ride height valve being 1/2" too high. This caused the LR and RF corners to carry more weight. When it was corrected, both fronts were near 7600# for a total of 15,200. I don't know where the other 100# went. After that, I had the 60/40 proportioning valves replaced with adjustable regulator valves. This allowed me to determine how much weight the tag axle would carry. By lowering the tag load from 9000# down to 5000#, the drive axle went from roughly 15,000#(which is too light) up to 19,500# and the steer axle went from 15,200# down to 14,600#. I do not have the exact figures with me, but you get the idea. The end result is a better balanced weight distribution and a better safety cushion for the front tires.

tbbg II · 08-16-2015, 05:01 AM

[QUOTE=Crasher;2698263]

Quote:

Originally Posted by tbbg II

The uneven front tire weights was due to the LR ride height valve being 1/2" too high. This caused the LR and RF corners to carry more weight. When it was corrected, both fronts were near 7600# for a total of 15,200. I don't know where the other 100# went. After that, I had the 60/40 proportioning valves replaced with adjustable regulator valves. This allowed me to determine how much weight the tag axle would carry. By lowering the tag load from 9000# down to 5000#, the drive axle went from roughly 15,000#(which is too light) up to 19,500# and the steer axle went from 15,200# down to 14,600#. I do not have the exact figures with me, but you get the idea. The end result is a better balanced weight distribution and a better safety cushion for the front tires.

Thanks.

mpierce · 08-16-2015, 06:27 AM

Quote:

Originally Posted by bamaboy473

How does one learn dry weight for a coach? Seems that we want to know that; compare to carrying capacity, so we know how much stuff and fluids we can safely carry.

How to get that info?

Go to a scale at most truck stops, and get it weighed. Easy pea see!

mpierce · 08-16-2015, 06:29 AM

Quote:

Originally Posted by bamaboy473

The brochure shows a 14,600 front axle, 20,000 rear, and 10,000 tag.

Gross vehicle is 44,600 and combined is 54,600.

Here's my question: IF the vehicle (dry, unloaded) weighs 44,600, then the 400HP engine isn't enough power to get it up the hill.

How do axle weights figure into what the dry weight actually is?

Since when isn't 400 hp enough to go up a hill? That is a LOT of power.

My peterbilt has a 550 hp C-15 CAT engine, but grosses at 80,000#. I go up the hills just fine! You have a MUCH better power to weight ratio than I do!

mpierce · 08-16-2015, 06:32 AM

Quote:

Originally Posted by bamaboy473

The brochure shows a 14,600 front axle, 20,000 rear, and 10,000 tag.

Gross vehicle is 44,600 and combined is 54,600.

Here's my question: IF the vehicle (dry, unloaded) weighs 44,600, then the 400HP engine isn't enough power to get it up the hill.

How do axle weights figure into what the dry weight actually is?

You have it all wrong.

Gross is TOTAL weight of vehicle and everything inside, NOT dry/unloaded weight. 44,600# is the maximum the vehicle can weigh.

Combined weight is when it is towing another vehicle, then the MH itself is limited to the 44.6K, and you are allowed a toad of 10K. For a total of 54.6k, COMBINED toad and MH.

Gordon Dewald · 08-16-2015, 11:51 AM

Quote:

Originally Posted by bamaboy473

How does one learn dry weight for a coach? Seems that we want to know that; compare to carrying capacity, so we know how much stuff and fluids we can safely carry.

How to get that info?

Hi Rick and Sandy;
The dry weight of the coach is pretty much useless. The only time it will be dry is when it is manufactured and then for a very short time. They have to add fuel to it to get it out of the yard. There goes dry weight.

The dry weight will give you a good approximation of what you can add to the coach. You can ask your salesman or the company what the dry weight is and they will give you a number. Likely that number is before any accessories or additions that you add to the build.

CCC is something to use as a guideline as that is what the manufacturer thinks you can add to an average build. It will be close enough to get a very good idea of the amount of stuff you can add. Include a larger fuel tank, extra water tank, etc and the numbers will be close.

The important numbers are GVWR, GAWR (front) and GAWR (rear). If you are going to tow the next important number is GCWR. If you dont exceed any of them you are golden.

Obviously the best thing to do is get the coach with the biggest CCC and GCWR. If you think you will be close I would try to get actual weights so you know exactly what you are getting into. It will be frustrating and perhaps costly to get a coach that you will soon grow out of.

Having a few thousand unused capacity is much better than being over by several thousand.

bamaboy473 · 08-16-2015, 12:18 PM

Quote:

Originally Posted by mpierce

Go to a scale at most truck stops, and get it weighed. Easy pea see!

Quote:

Originally Posted by mpierce

You have it all wrong.

Gross is TOTAL weight of vehicle and everything inside, NOT dry/unloaded weight. 44,600# is the maximum the vehicle can weigh.

Combined weight is when it is towing another vehicle, then the MH itself is limited to the 44.6K, and you are allowed a toad of 10K. For a total of 54.6k, COMBINED toad and MH.

The brochure shows a 14,600 front axle, 20,000 rear, and 10,000 tag.

Gross vehicle is 44,600 and combined is 54,600.

If 14,600 + 20,000 = 34,600 what does that number represent?

Steve Ownby · 08-16-2015, 02:13 PM

Quote:

Originally Posted by bamaboy473

The brochure shows a 14,600 front axle, 20,000 rear, and 10,000 tag.

Gross vehicle is 44,600 and combined is 54,600.

If 14,600 + 20,000 = 34,600 what does that number represent?

Nothing. You must add the tag rating of 10,000 pounds and that 3 axle total is the GVWR.

Steve Ownby
Full time since '07

bsnids · 08-16-2015, 03:01 PM

Quote:

Originally Posted by bamaboy473

The brochure shows a 14,600 front axle, 20,000 rear, and 10,000 tag.

Gross vehicle is 44,600 and combined is 54,600.

Here's my question: IF the vehicle (dry, unloaded) weighs 44,600, then the 400HP engine isn't enough power to get it up the hill.

How do axle weights figure into what the dry weight actually is?

GVWR IS THE MAX WT. WHEN FULLY LOADED THAT YOU SHOULD NOT EXCEED. IN YOUR CASE, 54,600 is the dry wt. of 44,600 plus your family's at. Plus fluids plus all your stuff. Remember water weighs 7.5 lbs. per gal so a full tank adds lots of wt.

bsnids · 08-16-2015, 03:05 PM

Engines designed for 95% of driving which is mostly on flat terrain. Just learn to down shift manually going up hills to keep the RPMs over 1500 to prevent overheating. So what if you have to slow down a lot. The truckers do it all the time.

TurtleKent · 08-16-2015, 03:30 PM

Last year at LD I saw a used hi-$$ rig(can't remember, Prevost or Newell) with a C.C.C. of 1229#. All that marble and mirrors and chrome weigh a lot! I would bet most coaches are carrying a good bit more than 1229#. And that does not consider weight and balance for each axle. Many newer 40' rigs are near their weight limit on the drive axle, while many newer 42-45' tag axle rigs are near their weight limit on the steer axle(or overweight)! Read the forums, and buyer beware.