Just read this post on CF I had no idea that the WDH increased the TBO , gonna check mine to calculate the TBW
I know that the subject of Tow Ball Overhang (TBO) has been discussed widely before, but I feel that most people do not know what TBO is or they don't care, EXPECIALLY WHEN THEY USE A WEIGHT DISTRIBUTION HITCH (WDH). Ignorance regarding TBO and WDH use, along with loading your caravan and speeding may be a contributing factor as to why there are so many caravan rollovers lately.
What is TBO. It is simply the distance between the centre of the rear axle and the centre of the tow ball.
I have a 2017 Isuzu Dmax Dual Cab and tow a caravan with an ATM of 3000kg and use a WDH and a McHitch.
My owners manual states that the TBO is 1377mm and at that length the vehicle may tow up to a 3500kg caravan with a maximum 350kg tow ball weight. With the WDH installed, the TBO increases to 1577mm, thus increasing the load applied to the rear axle. Common sense!
I questioned an RTA approved Automotive Engineer regarding this and he stated exactly what I already presumed above and he said to apply the following simple formula:
Stated Vehicle TBO, divided by the actual TBO x the tow ball weight = recalculated ball weight
1377mm divided by 1577mm x 350kg = 305.6kg
As you can see, by using a WDH, the ball weight of my Dmax has reduced from 350kg to 305.6kg. If I had a larger van and loaded it up to apply a ball weight of 350kg then it would be extremely overloaded. The performance of the rig would be compromised and an accident could more easily occur!
I am not raising this subject to discuss whether to use a WDH or not, but to make caravaners aware and understand "TOW BALL OVERHANG" and possible by using that knowledge, reduce the risk of an accident.
I would appreciate it if everyone would distribute this to friends in an effort of road and personal safety!
outlaw40 said
10:24 AM Jan 21, 2018
Been following this and other stability related posts on c/f for some time. Calculated that my rig that i have been happily towing around for quite some time is infact a death trap. Think i will huddle in a corner never to leave home again!
Dickodownunder said
10:27 AM Jan 21, 2018
Good info Mezza and easy to calculate.
Different hitches provide varying overhang dimensions...in you case above if you used a ball and removed the McHtich but retained the HR WDH (assuming it is a HR brand) then your allowance would be 326.30 kg
It just goes to show that each vehicle may be different depending on the hitch and other hardware.
C00P said
08:08 PM Jan 21, 2018
Hi Mazza
This is new to me. Can you post a link to the original article, I'd like to read up on it.
Cheers
C00P:
Dickodownunder said
10:00 PM Jan 21, 2018
C00P wrote:
Hi Mazza
This is new to me. Can you post a link to the original article, I'd like to read up on it. Cheers
C00P:
From this site rules.
As previously stated, the Grey Nomads forum exists primarily to allow people interested in the grey nomad lifestyle to help, encourage and guide one another in their big adventures. Posts are not to be used for the sole purpose (however well disguised) of promoting other websites or forums, or advertising products or services. Posts deemed to have breached this guideline will be removed.
Might pay you just just to google the info
PeterD said
12:22 AM Jan 22, 2018
C00P wrote:
Hi Mazza
This is new to me. Can you post a link to the original article, I'd like to read up on it. Cheers
C00P:
mezza56 copied and pasted the complete message. There is no need to cross post the other forum for the reasons that Dickodownunder mentioned.
The Expats said
04:00 PM Feb 1, 2018
Hi all, bought the 275 kg Mr hitch wdh , the only problem was when i fitted to the Triton the shank was 100 mm further out than the standard ball carrier. After a Google search about drilling another hole closer to the receiver and got the 600 million different experts answers like"it will weaken the shaft" and "you need to get a engineers approval" i bit the bullet and asked Mr Hitch. Answered straight away with "yes why not" . Now to get it drilled!!!! , no tbo problems now.
What is TBO. It is simply the distance between the centre of the rear axle and the centre of the tow ball.
I have a 2017 Isuzu Dmax Dual Cab and tow a caravan with an ATM of 3000kg and use a WDH and a McHitch.
My owners manual states that the TBO is 1377mm and at that length the vehicle may tow up to a 3500kg caravan with a maximum 350kg tow ball weight. With the WDH installed, the TBO increases to 1577mm, thus increasing the load applied to the rear axle. Common sense!
I questioned an RTA approved Automotive Engineer regarding this and he stated exactly what I already presumed above and he said to apply the following simple formula:
Stated Vehicle TBO, divided by the actual TBO x the tow ball weight = recalculated ball weight
1377mm divided by 1577mm x 350kg = 305.6kg
As you can see, by using a WDH, the ball weight of my Dmax has reduced from 350kg to 305.6kg. If I had a larger van and loaded it up to apply a ball weight of 350kg then it would be extremely overloaded. The performance of the rig would be compromised and an accident could more easily occur!
I am not raising this subject to discuss whether to use a WDH or not, but to make caravaners aware and understand "TOW BALL OVERHANG" and possible by using that knowledge, reduce the risk of an accident.
I would appreciate it if everyone would distribute this to friends in an effort of road and personal safety!
Different hitches provide varying overhang dimensions...in you case above if you used a ball and removed the McHtich but retained the HR WDH (assuming it is a HR brand) then your allowance would be 326.30 kg
It just goes to show that each vehicle may be different depending on the hitch and other hardware.
This is new to me. Can you post a link to the original article, I'd like to read up on it.
Cheers
C00P:
From this site rules.
As previously stated, the Grey Nomads forum exists primarily to allow people interested in the grey nomad lifestyle to help, encourage and guide one another in their big adventures. Posts are not to be used for the sole purpose (however well disguised) of promoting other websites or forums, or advertising products or services. Posts deemed to have breached this guideline will be removed.
Might pay you just just to google the info
mezza56 copied and pasted the complete message. There is no need to cross post the other forum for the reasons that Dickodownunder mentioned.