I tow a 22' enclosed trailer behind the DP in my signature. It has a 10,000 lb hitch with a 1000 lb tongue weight capacity.
I have been hauling a UTV weighing 1100 lbs in the front and a 3200 lb Suzuki Grand Vitara in the rear. I recently weighed the tongue with a scale(Sherline) and it weighed 1400 lbs...yikes!
The only loading option I have is putting the UTV in front and then load the Vitara backwards so that the engine is behind the axles. This reduced the tongue weight to 1200 lbs.
Is 200 lbs over the tongue rating a big No No, or do the manufacturers allow for a little overage? If not, how do I use a WDH on a DP?
It has ride height valves(always sits level)no matter how much weight is on the hitch, so how can I know if I am adjusting weight from rear to front of the DP?
There are people a lot more knowledgeable than me on here so I welcome any options or suggestions.
I have been hauling a UTV weighing 1100 lbs in the front and a 3200 lb Suzuki Grand Vitara in the rear. I recently weighed the tongue with a scale(Sherline) and it weighed 1400 lbs...yikes!
The only loading option I have is putting the UTV in front and then load the Vitara backwards so that the engine is behind the axles. This reduced the tongue weight to 1200 lbs.
Is 200 lbs over the tongue rating a big No No, or do the manufacturers allow for a little overage? If not, how do I use a WDH on a DP?
It has ride height valves(always sits level)no matter how much weight is on the hitch, so how can I know if I am adjusting weight from rear to front of the DP?
There are people a lot more knowledgeable than me on here so I welcome any options or suggestions.
wildmanbaker wrote:bjbear wrote:
Although it is true that a DP with air suspension will compensate for extra weight on the hitch receiver by raising the rear of the coach, that is not the primary purpose of a WDH.
The WDH does 2 important jobs.
1) Reduces the load on the rear axle and distributes it between the front axle and the trailer axle(s). Even though the coach may adjust the air to raise the rear of the coach, it does not affect the extra loading on the rear axle. If your tongue weight pushes you over the GAWR or your tire rating, then you should use the WDH.
2) The second purpose (and in my opinion the most important) of the WDH is to reduce the torque loading on the receiver. When the tongue weight exerts a downward force on the ball, it induces a twisting force (torque) on the receiver. The resulting torque has 2 components. First, is the static loading. This is the tongue weight when the rig is not moving. The second is the dynamic loading which is the resulting force on the ball when the vehicle is moving. For example, when the coach goes over a bump, the hitch moves down and then rebounds. This downward movement can exert many times the static loading as the suspension stops the downward movement and rebounds. The WDH counteracts this dynamic loading greatly reducing the torque on the receiver. This is especially critical if using a hitch extension of any kind.
So the bottom line, is that if your tongue weight exceeds the rating on your receiver OR you are using a hitch extension, you should use a WDH. This is true even if you coach air suspension can keep your coach level.
The following diagram illustrates the effect of a WDH.
Tell you what, find a scale in your area and give this a try on you MH. Get back to us on what you find out, OK. There are a lot of things that work on paper, but not in real life.
I agree with wildman. Your drawing showing the PICKUP TRUCK changing rear height is totally different than a similar experiment with a DIESEL MOTORHOME where the rear height remains constant. (i.e. doing the same thing as the WDH. I would like to see a set of data from a similar test ON THE SCALES except with your DP. Data is wonderful. Accurate data is even better.
wildmanbaker wrote:bjbear wrote:
Although it is true that a DP with air suspension will compensate for extra weight on the hitch receiver by raising the rear of the coach, that is not the primary purpose of a WDH.
The WDH does 2 important jobs......................
Tell you what, find a scale in your area and give this a try on you MH. Get back to us on what you find out, OK. There are a lot of things that work on paper, but not in real life.
OK ... since you asked. Having spent my career in engineering, I am pretty careful to make sure I know what I am talking about before I put anything out......
Fortunately, I have a set of scales not far from where I live so when I wanted to engineer a hitch extension for my truck for use with a camper, I was able to verify my paper calculations with real life observations. Below is the results of some of work. Note that like my previous drawing, when you tighten the chains on the equalizer, more weight is added to the steer axle and the trailer axles and the equivalent weight is removed from the drive axle of the truck.
Although this data was from my truck, it applies equally to my MH.
Think of it this way.
On a motorhome, when you add weight to the hitch........
- The rear of the MH goes down
- The air level valves sense this change and add air to raise the rear of the MH back to the design level
- The air bags are pushing upward on the frame. The increase in force is equal to the weight from the hitch
- At the same time, the air bags are pushing down on the drive axle with an equivalent force, increasing the loading on your tires and axles.
The end result therefore is that when you measure the resultant weight on the drive axle, it will have increased. Doesn't matter if the rear of the MH is sagging or has been forced back to normal position. The weight has still been added to the axle and tires.
There is a reason that the manufacturers of hitches and receivers give different ratings for use with and without an WDH. If your actual tongue weight is over the rating for your receiver and hitch, then use a WDH.
bjbear wrote:
Although it is true that a DP with air suspension will compensate for extra weight on the hitch receiver by raising the rear of the coach, that is not the primary purpose of a WDH.
The WDH does 2 important jobs.
1) Reduces the load on the rear axle and distributes it between the front axle and the trailer axle(s). Even though the coach may adjust the air to raise the rear of the coach, it does not affect the extra loading on the rear axle. If your tongue weight pushes you over the GAWR or your tire rating, then you should use the WDH.
2) The second purpose (and in my opinion the most important) of the WDH is to reduce the torque loading on the receiver. When the tongue weight exerts a downward force on the ball, it induces a twisting force (torque) on the receiver. The resulting torque has 2 components. First, is the static loading. This is the tongue weight when the rig is not moving. The second is the dynamic loading which is the resulting force on the ball when the vehicle is moving. For example, when the coach goes over a bump, the hitch moves down and then rebounds. This downward movement can exert many times the static loading as the suspension stops the downward movement and rebounds. The WDH counteracts this dynamic loading greatly reducing the torque on the receiver. This is especially critical if using a hitch extension of any kind.
So the bottom line, is that if your tongue weight exceeds the rating on your receiver OR you are using a hitch extension, you should use a WDH. This is true even if you coach air suspension can keep your coach level.
The following diagram illustrates the effect of a WDH.
Tell you what, find a scale in your area and give this a try on you MH. Get back to us on what you find out, OK. There are a lot of things that work on paper, but not in real life.
Although it is true that a DP with air suspension will compensate for extra weight on the hitch receiver by raising the rear of the coach, that is not the primary purpose of a WDH.
The WDH does 2 important jobs.
1) Reduces the load on the rear axle and distributes it between the front axle and the trailer axle(s). Even though the coach may adjust the air to raise the rear of the coach, it does not affect the extra loading on the rear axle. If your tongue weight pushes you over the GAWR or your tire rating, then you should use the WDH.
2) The second purpose (and in my opinion the most important) of the WDH is to reduce the torque loading on the receiver. When the tongue weight exerts a downward force on the ball, it induces a twisting force (torque) on the receiver. The resulting torque has 2 components. First, is the static loading. This is the tongue weight when the rig is not moving. The second is the dynamic loading which is the resulting force on the ball when the vehicle is moving. For example, when the coach goes over a bump, the hitch moves down and then rebounds. This downward movement can exert many times the static loading as the suspension stops the downward movement and rebounds. The WDH counteracts this dynamic loading greatly reducing the torque on the receiver. This is especially critical if using a hitch extension of any kind.
So the bottom line, is that if your tongue weight exceeds the rating on your receiver OR you are using a hitch extension, you should use a WDH. This is true even if you coach air suspension can keep your coach level.
The following diagram illustrates the effect of a WDH.
The WDH does 2 important jobs.
1) Reduces the load on the rear axle and distributes it between the front axle and the trailer axle(s). Even though the coach may adjust the air to raise the rear of the coach, it does not affect the extra loading on the rear axle. If your tongue weight pushes you over the GAWR or your tire rating, then you should use the WDH.
2) The second purpose (and in my opinion the most important) of the WDH is to reduce the torque loading on the receiver. When the tongue weight exerts a downward force on the ball, it induces a twisting force (torque) on the receiver. The resulting torque has 2 components. First, is the static loading. This is the tongue weight when the rig is not moving. The second is the dynamic loading which is the resulting force on the ball when the vehicle is moving. For example, when the coach goes over a bump, the hitch moves down and then rebounds. This downward movement can exert many times the static loading as the suspension stops the downward movement and rebounds. The WDH counteracts this dynamic loading greatly reducing the torque on the receiver. This is especially critical if using a hitch extension of any kind.
So the bottom line, is that if your tongue weight exceeds the rating on your receiver OR you are using a hitch extension, you should use a WDH. This is true even if you coach air suspension can keep your coach level.
The following diagram illustrates the effect of a WDH.
tropical36 wrote:ACDNate wrote:
I'm not sure I understand why, those of you who said so, you don't think a wdh will help.
I've used a wdh with a trailer behind my truck and it significantly lightened the load on the rear end of the truck and put some weight back to the front axle.
Why would it not have the same affect here?
I've often asked the same question, but have never heard from anybody using one and giving the actual weight transfer.
It's gotta do something towards that goal, so the question is how much.
I asked that question at the beginning of my thread. From recall, a few people said that it probably wouldn't have much, if any effect on a DP, and possibly could make handling worse.
I have looked at lots of DP's pulling trailers and so far, have not seen any with a WDH. There must be a reason for that.
