Larger Trailer Weight Distribution Hitches - who uses 'em on their boat trailer - why

[ozscott]

I have never used a weight distribution hitch nor anti-sway bars on my 21 foot Vagabond with dual axles being towed by my 02 Discovery (stock coil suspension not air bag) however I am about to enter caravan ownership and even most sized vans tend to have them. I know of several van owners that wouldnt leave home without them.

I cannot recall seeing many boats trailers with them...is that because they take too long to install for relatively short outings or other reasons.

Just wondering what people think of this and also who uses them, what type of trailer and tow vehicle and why?

Cheers

[wazsratbag]

Hi
I used to have a seafarer victory 5.9 as well as a large 22' caravan. I never used weight distribution hitches with the victory as it was balanced well and the tow ball weight was not enough to worry my Nissan Patrol, it remained fairly level. Towing the caravan on the other hand is a totally different matter. When I hitch the van to the patrol the tow ball weight (about 250kg) is enough to cause a noticable effect on the patrol. I do not even move the van out of the yard without using the WDH to level the Patrol.
The two "trailers" towed very differently, the boat trailer had the axles more towards the rear and was much more stable, whereas the van has the axles more towards the middle and can be affected by other forces more easily.
Before any one else comments, no I never did try towing both the van and boat together behind the Patrol. I always had dreams thou of getting a large tilt tray tow truck, putting the boat on the trailer on the tray, hitching the van behind and off we go. Oh well, I can still dream!!!

[wazsratbag]

Hi
I used to have a seafarer victory 5.9 as well as a large 22' caravan. I never used weight distribution hitches with the victory as it was balanced well and the tow ball weight was not enough to worry my Nissan Patrol, it remained fairly level. Towing the caravan on the other hand is a totally different matter. When I hitch the van to the patrol the tow ball weight (about 250kg) is enough to cause a noticable effect on the patrol. I do not even move the van out of the yard without using the WDH to level the Patrol.
The two "trailers" towed very differently, the boat trailer had the axles more towards the rear and was much more stable, whereas the van has the axles more towards the middle and can be affected by other forces more easily.
Before any one else comments, no I never did try towing both the van and boat together behind the Patrol. I always had dreams thou of getting a large tilt tray tow truck, putting the boat on the trailer on the tray, hitching the van behind and off we go. Oh well, I can still dream!!!

[Angla]

I used to have a 5.2 metre rumrunner half cab and pulled it with a 2.0 litre mitsubishi swb van. It would sway nearer to 100km/hr without level riders it was a dog but with the level riders it was a dream to pull at any speed.

Once you have seen the difference you will not go back.

I don't currently use them on the cruisecraft as it sits great and tows great without assistance

Cheers
Chris

[ozscott]

Fellas - your experience with you boat towing is the same as mine. Never have a drama behind the Discovery (even with its relatively short wheelbase). I wonder why vans tend to throw too much weight on the hitch?

Cheers

[Noelm]

it is all to do with the weight on the tow ball and the weight of the trailer, a caravan usually has the wheels almost in the middle of the van, and a van weighs bugger all really, just a big light weight "box" so, because you have this almost balanced "box" on the back, a pendulum effect can take place and the van starts to get a bit of a "wobble" that slowly ends up in a full on sway, then onto a full on tip over, but a boat is quite low and the weight is mostly down low, plus the wheels are usually set well back, trust me, move your boat trailer wheels to the centre of the trailer, and you will soon see a sway just like your caravan! conversly, move your van wheels to the very back (if you could move them that is) and your van will tow like a dream. The "anti roll" bars or "load levelers" are in fact just like the anti roll/sway bar on your car, and the load level system works by spring tension that is trying to lift the trailer up at the coupling by the tension you apply with the long spring things that hook over the gizmo on the drawbar.

[charleville]

A great explanation, Noelm. Many thanks!

I have had a couple of interesting experiences with towing matters.

1. The first is that I built a box trailer about four years ago and put quite a long drawbar on it which means that the trailer wheels are well back relative to what you would normally see on box trailers. Yes, it tows beautifully as you suggest but I suppose that it should as it is only lightweight.

Even more useful to me though is that with a longer wheel base back to its wheels, it backs much easier than the normal short wheelbase commercially available box trailers do. ie, on a short wheelbase trailer, a short turn of the steering wheel will screw the trailer around pretty easily. Not so on a longer wheel base trailer. The reasons are obvious - leverage principles - but I had not considered that when I was building the thing.


2 Secondly, about 30 years ago, when working as an engineer doing a field inspection north of Bundaberg, I was standing on a high bridge over a river, which was a damn long way down and with no pedestrian walkway nor side rails to the bridge. This was the main highway north and a very good quality fast road.

Over the hill from the north came a station wagon towing a caravan and traveling a tad too quickly. Just as he neared the bridge, he blew a back tyre on the driver's side and the whole rig did a 360º spin right in front of me and my colleague right on the bridge. Right in front of us on that bridge! I suppose that he slammed on the brakes which caused that spin.

All this happened within five or ten metres of us and there was nowhere to run to. If we had jumped over the side of the bridge, we would have been seriously injured or killed by the fall. It really was a long way down to the river below us. Not that there was any time to think of doing that anyway. My colleague's nerves fell apart at that point and he took quite some time to compose himself afterwards. "We could have been the only casualties out of that!" was what he kept repeating whilst shaking profusely for a long time. Poor bugger!

It could have been a disaster not only for us because the station wagon had a family inside. Given another set of circumstances with, say, oncoming traffic and that high bridge and it sure would have been a mess.

Anyway, I wonder if ride levelers might have saved that spin.



When I bought my brand new LPG Falcon three years ago, I optioned the heavy duty towbar and one of the deal sweeteners was the inclusion of the Hayman-Reese levelers which are still sitting in their shrink plastic wrapping in my garage. They sure seemed to be unbelievably pricey for what they are - like about $750 at the time. I don't seem to need such things when I am towing my Quinnie. thankfully.



.

[Noelm]

the length of the "wheelbase" has a huge impact on how easy a trailer reverses, my mate has a tiny box trailer that is a nightmare to reverse, it reqires minute movements of the steering or it will jack knife in an instant, my own boat has a very long trailer, with the wheels way back (lots of towball weight) and you can reverse it with your eyes closed (well almost) big steering input is needed to make it turn off course, and you could tow it at any speed if you were game, (just a "throw away" statement, I do not condone high speed towing) I also used to have an old 18' Sharkcat that was very light on the ball (you had to stand on the trailer to get it to lower onto the ball) and that was downright suicidal at anything over 75KPH, (if you did get that fast before you crashed) I moved the wheels back and fixed it in an hour or so!

[FNQCairns]

Levelrs are a layover from the 60s and 70s when a bloke bought a HQ or any of the softly sprung family cars sold almost exclusively in that period.

They worked but so would have stiffer springs in the first place, the scenario kept repeating thought the 90s too with the grey nomad falcons.

Levellers have their place but stiffer rear springs work in an identical sense to keep PSI down force upon the front springs, each to their own if towing heavy enough and most importantly not very often and would like to keep the factory comfortable ride for the majority of the time used.

[Jarrah Jack]

I used to tow a 23 ft trailersailer which generally have the trailer wheels closer to the center of the trailer cause of that heavy keel. It towed well behind an old v8 valiant but when I hitched it to a cj7 jeep it became very dangerous and wanted to sway all over the place. I put on some hitches which helped a lot but not totally.

Towed many things with different vehicles since and have never felt the need to resurrect the hitches.

[ozscott]

FNQ - I would have thought the exact same thing as you (and I must admit I am struggling with the engineering and physics principles of load level bars) but many of the sites and explanations about load bars say that stiffer springs in the rear of the tow vehicle do not throw load forward onto the front axle of the tow vehicle even if they keep the load 'level' - ie even if the stiff springs keep the car level...I would have thought the opposite but I need an engineer to explain it to me!

Cheers

[Noelm]

the physics of load level bars (or wharever you want to call them is simple) imagine you get a long bar and connect it to your towball, now with the lever extending rearward, lift the end of it, you infact lift the rear of the car (without increasing spring rate), now if you "hook" the end that you lifted over something so it can't spring back, you have just levelled the load out, now if you fit one on each side (as they do) you now have a "loaded" spring on each sid eof your towball, if the trailer wants to "twist" in the opposite direction to the car, it will need to apply a heap more tension the bar/spring (same as your sway bar on your car) so it helps to keep everything going in the same line, as well as lift some load off the towball, while leaving the wheels in the same place, so it all tows "nice" get the picture??

[Bros]

WDH will absolutely nothing for caravan sway. Sway of van comes first from the design and secondly from the loading. The most stable van or trailer is one with the wheels level with the back of the trailer.
Now that is not possible due to ball weight so the axle needs to be moved forward and the further forward you bring it the more stability is affected. That is in the design.
Secondly if you load the van at the rear not over the axle you can set up a pendulum effect which when it starts will either stop rapidly or will continue on amplifying at each oscillation until the rig leave the road.
WDH hitch role is to eliminate the rotation around the back axle when the ball load tries to lift the front axle. WDH applies a reverse weight to counter this reduction in weight to the front axle.
The rule of thumb for ball weight is 8% to 12% of the van loaded weight.
Strangely enough vans in Europe have a ball weight of 5% and WDH are non existent but they are extremely fussy in loading their vans directly over the axle.
Speed is also a factor in an uncontrollable sway. Caravans are close on the limit of stability

[Noelm]

Bros, isn't that is what I said?, loading the rear of the van, in effct is the same as having the wheels too far forward, on a caravan, moving the wheels would rarely be an option, they are fixed, so load has to be done with some care, but a boat trailer can have the wheels/axles moved almost the entire length of the frame, but load movement is limited, as in the motor is always on the back, only a small amount of "stuff" can be shifted about, so, caravans and boats are completely different, but sort of still the same (if you get what I mean)

[Noelm]

hey, I might add, I do not use nor have ever used a set of levelling bars, but I have connected up heaps of them for "pensioners" that are traveling and cannot do so themselves, after unhooking the van to use the car for a bit, and indeed as FNQ says, they were a very common thing in the years ago, I gues these days there is heaps more suitable tow vehicles around, like Landcruisers and Patrols and stuff, back in the early days, Mum and Dad loaded the poor old Kingswood to the hilt with luggage and kids, hooked up the old aging Millard and off they went, Dad peering at the temp light on every hill waiting for the inevitable over heat, the kids fighting in the back, and good old Mum with a thermos and a bit of a snack to soothe Dads frazled nerves after a few hours on the road.