caravan sway

jimmie44a · Newbie

caravan sway

DiscoMuzz · Member

Hi!

Also a newbie.

Have a look at this.

http://www.supertramp.com.au/forum/forum_posts.asp?TID=1993&title=ve-commodore-v-pathfinder

Cheers

Murray

VHW · Senior Member

You could also check out this link which mentions towing with the Commodore;

http://www.caravanersforum.com/viewtopic.php?f=2&t=10956&p=153852&hilit=Caravan+Sway#p153852

-- Edited by VHW on Friday 5th of November 2010 12:04:01 AM

Cupie · Guru

Hi ..

A first word .. don't pull your van anywhere before you fix this problem!

Before getting into such things as suspensions or alignments I would start with the basics like -

1. Ball weight ...
Check your van's 'ball weight'.
ie the downward pressure that the van puts on the hitch.
Should be around 10% of your loaded van's weight.

Go to a public weigh bridge & weigh it still hitched with only the van's wheels on the weigh bridge. (alternative unhitch the van but leave the jockey wheel off the weighbridge This is W1

Weigh the van unhitched (jockey wheel on the weigh bridge this time). This is W2

W2-W1 = Ball weight which should be close to or a bit greater than 10% 0f W2

(make sure that you do this with the van fully laden ready for a trip.)

The ball weight can be changed by relocating your load.

2. I wouldn't think of driving out of the yard without a correctly fitted weight distribution hitch.

3. Check that all bolts on the tow bar, ball & van coupling etc are tight. No cracked welds either.

4. Ensure that all tyre pressures are correct & wheels balanced (particularly on the van). Look for uneven tyre wear on the van. Might indicate bad alignment.

Hope this is of some assistance.

-- Edited by Cupie on Friday 5th of November 2010 09:34:41 AM

JRH · Guru

What Cupie says it is spot on, make absolutely sure you get a suitable WEIGHT DISTRIBUTION HITCH it is of the utmost importance.

I know I am shouting here but I feel it is that important for YOUR safety and the safety of other road users.

brickies · Guru

Thanks Cupie you covered the subject well down to the key point which I feel is important correctly fitted Weight Distribution Hitch , when adjusting the WDH make sure that the distance from the road to centre of the front wheel arch is the same with caravan on and off if not use your WDH to do so , must have the right weight on front steering to stop the sway , if your front wheels are not in proper contact with the road this will cause swaying

Pam · Guru

simple solution, just don't drive above 95 k

jimricho · Guru

Pam wrote:

simple solution, just don't drive above 95 k

To quote H L Menkin... For every complex problem there is an answer that is clear, simple, and wrong.

Sorry Pam, but I think this is a case in point.

Jim

-- Edited by jimricho on Friday 5th of November 2010 05:50:07 PM

VHW · Senior Member

Hi Jim & Chris,

I basically agree with the info given by Cupie and the others, except for keeping your speed down to solve the problem (sorry Pam).

You do not give an indication of what State or Area you are in, however if you have a respected caravan repair business in your area I would ask their advice, especially letting them know your tow vehicle. Some vans less than 17' DO NOT need a WDH and indeed some vehicle manufacturers do not recommend them (read your tow vehicle manual or ring your local vehicle servicing department for advice on that).

You also need to check that your current tow bar is secure and correctly fitted, whether your van sits level etc.

We can only give you what we think is good advice, but the advice of proper experts is best sought, something is clearly wrong with your van and it may mean taking it to a respected repairer to have it checked over etc.

Agree with Jimricho;

"To quote H L Menkin... For every complex problem there is an answer that is clear, simple, and wrong."

Best to get it right from those qualified to inspect and give advice on what the problem is.

Good luck,

VHW · Senior Member

DiscoMuzz wrote:

Hi!

Also a newbie.

Have a look at this.

http://www.supertramp.com.au/forum/forum_posts.asp?TID=1993&title=ve-commodore-v-pathfinder

Cheers
Murray

Edit: Link "activated" to make it clickable

ozjohn · Guru

If it sways at 100 then it's only a matter of time or place before it lets go with a violent uncontrollable sway at 90 or any other speed for that matter.
Load the van (including full water tank) and then check the ball weight. Ideally it should be around 10% of the vans loaded weight.
Check that the tyres are not under inflated and then fit an approriate WDH.
Hopefully your problems will be solved.
ozjohn.

Cruising Granny · Guru

What Pam said initially, but you have to take steps to avoid any sway.
It's a single axle van, so it's even more important to make sure the weight is distributed evenly over the axles of the van and in the car.
The car's tow bar may be too low, or too high as well. What leveller/stabiliser kit are you using? Has it been fitted correctly for your configuration?
It's all about balance, weight distribution and speed.
Why would you want to tow anything any faster than 95kph?
I tow at 85-90KPH and it's always smooth travelling.
Take it easy man! You're on holidays, not racing to an appointment for that big deal.
Don't take unnecessary risks. It's not just you at risk, but anyone who's passing you in either direction while you van is doing its swing thing.

beachball57 · Senior Member

jimmie44a wrote:

Hi. We are brand new to caravanning and have a question if anyone can
help please.
Sway....
1)We just bought a 15.5 feet Prattline van (1980model) and it sways badly
and feels dangerous at 100 kph.
It tows perfectly at 95 kph and only sways when over this speed. Does anyonehave any idea why?
a)We are towing it with a big 3.8 lt. Commodore.
b) There is no extra weight anywhere inside and it only has the usual bed,fridge etc not even an annex.
c) The tyres are properly inflated.
d)The van's weight is approx.1000 kgs.
We will limit our speed to 95kph. but I suspect something, somewhere isn't quite right(it shouldnt sway at all should it ?) and safety is a top priority. Do we need to or should we fit a "Weight Distribution Hitch"? or is there another simple reason for high speed only sway ?? Anybody help?

Thank you. Jim &Chris.

hi not sure where you are but my wife works for a tow bar fitting company here in adelaide,,, first check the ball weight of the van any good c'van sales yard should have a ball weight scale its a tripod with a scale on it you connect it to the va aand measure the ball weight from there,, second,, for that size van you'd need a heavy duty weight distrobution hitch a 350 kilo plus is the heary duty one and it must be fitted correctly also,, the hitch transfers wight from the back of the car to the front steering,, if it's to light it won't transfer enough weight,,,,also make sure you have the right sort of tow back for that size van again a heavy duty one is in order,, the van may also be packed wrongly perhaps you need to make sure the weight of your "stuff in the van"" is spread out evenly ,, try these things first before looking at susspension and stuff i doubt that it would be that,,, even once you get it sorted just because you can do 100 doesn't mean that it's such a good idea towing a van 95 you'll get better milage anyway and get to where you're going just as quick
cheer tony

ozjohn · Guru

Beachball.
He definately won't need a 350Kg WDH as his Holden is only permitted a ball weight of 210Kg if it's fitted with the heavy duty hitch receiver. (Max tow Weight 2100Kg)
Depending on the loaded weight of the van which must be less than 2100Kg and allowing for a 10% ball weight then a suitable WDH can be fitted. However owing to Holdens limits the maximum strength WDH required will be 250Kg such as a Haymen Reese 550.
Cheers, ozjohn.

VHW · Senior Member

Hi again Jim and Chris,

This link gives some info on WDH, it's a US site and refers to "trailers" caravans in our language. Also the Hayman Reese site give info as well if you want to look that up.

See:
http://www.etrailer.com/faq-weightdistribution.aspx

and Hayman Reese;
http://www.lets-getaway.com/hitches-antisway-weightdistribution.htm

I have a caravan similar in size and weight to yours and DO NOT use a WDH and have been caravanning for many years. A WDH will not overcome your sway problem if it is due to other factors, you are just masking the problem. Check the other things out as stated on this thread first, then consider whether you need one or not for your size/weight van after getting professional advice on your van. Remember too that vendors selling WDH are there to sell their products, so just ensure they are an ethical company who are being upfront.

If you let us know what state you are in it would be a big help as some of us may know someone professional in your State or Area who will give you genuine free advice.

That is why it help for new members to specify a general area they live in on their profile rather than inconvenience members who are trying to help and spending their time doing so.

PS: All due respect to OzJohn whom I consider one of the qualified experts.

-- Edited by VHW on Sunday 7th of November 2010 06:04:27 PM

justcruisin01 · Guru

I would also be checking the vans axle & wheel alignment, even a straight solid axle can be misalighned, as in a bent axle. This will cause all sorts of problems including tyre wear & swaying.
This needs to be fixed before you wipe your self &/or some one else out.

jimricho · Guru

I don't have a WDH either... my rig has an ATM of 1350kg, a lot less than many larger vans but probably similar to or not much less than yours. It does have independent suspension and shockies however, and the tug (Pajero) is fitted with off-road suspension (OME) and "Airbagman" helpers. It also uses a Treg hitch which is not compatible with a WDH.

The whole set up tows well without any stability problems.

Smokeydk · Guru

Like Jim my hitch wont work with a WDH........but last Oct long weekend....I too couldnt go over 95k without the van swaying badly even to the point the back end of the pajero broke away on bituimin road.....hell scarey........got home.....went over everything...found the rear was heavy........I have 2 jerry can holders on back...that trip I only had one can on...checked tyre pressure.....pumped them to 36psi...I think I had one tyre pressure to low and with one jerry can.......the rear was off balance....causing the sway........I've just got home from trip to melbourne.....and never had a sway problem the whole trip.....weight was 1,200kg...ballweight 110kg.....average speed was 94kph.......

PeterD · Guru

Jim & Chris - How have you established that the weight of your van is around 1,000 kg? Is that the tare weight or the loaded weight?

That weight seems a little too low to me for a 15' van. I suggest you take your van to a weighbridge. Drive across the bridge until your tug is off the far end but you can lower the jockey wheel onto the bridge. Get the operator to give you the weight of the wheels. Then unhitch the van and get the total weight. The ball weight will be the difference between the two, it should be about 10% of the total weight.

If the ball weight is not around 10% this may be the cause of your instability problem. The other thing that can upset the balance is packing heavy things at the ends of the van.

Rolly · Guru

PeterD wrote:

Jim & Chris - How have you established that the weight of your van is around 1,000 kg? Is that the tare weight or the loaded weight?

There is no substitute for facts, in this case correct weights, and likewise none for keeping as much weight as possible over the axle/s and as low to the floor as is practicable.
The closer to the pivoting point - in this case the wheels - the less dynamic action; vertical and horizontal.
Putting weights at some distance from the axles is like adding weights to a long bar; the inertia and momentum are increased with the square of the distance.

Of course, little is noticable until there is some sudden vertical movement (causing bent draw-bars, A-frames and even caravan chassis) and/or hoizontal sway that can suddenly let all hell loose and end in disaster.

-- Edited by Rolly on Monday 8th of November 2010 04:40:08 PM

jimricho · Guru

Bit of a re-write of the Laws of Physics there Rolly.....

The moments about the pivot point (fulcrum) are a product of mass and the moment arm i.e. the distance from the fulcrum... not the square of the distance.... any pilots doing their weight and balance calculations when loading aircraft are aware of this.

All forces can be resolved to operate at the centre of gravity. Placing loads further from the pivot point will have a greater effect on the location of the centre of gravity but not in a square law ratio.

You comments however are generally valid and it is vitally important for Jim and Chris to resolve the problem

Jim

beachball57 · Senior Member

ozjohn wrote:

Beachball.
He definately won't need a 350Kg WDH as his Holden is only permitted a ball weight of 210Kg if it's fitted with the heavy duty hitch receiver. (Max tow Weight 2100Kg)
Depending on the loaded weight of the van which must be less than 2100Kg and allowing for a 10% ball weight then a suitable WDH can be fitted. However owing to Holdens limits the maximum strength WDH required will be 250Kg such as a Haymen Reese 550.
Cheers, ozjohn.

yeh that was a "typo"on my part sorry, ment to say 250 not 350

Rolly · Guru

jimricho wrote:

Bit of a re-write of the Laws of Physics there Rolly.....

Jim

Oo-oo-o-p-p-s-s

Old Timers' Disease strikes again!

You are, of course, absolutely right, Jim.

-- Edited by Rolly on Friday 12th of November 2010 04:56:24 PM

jimricho · Guru

Rolly wrote:

jimricho wrote:

Bit of a re-write of the Laws of Physics there Rolly.....

Jim

Oo-oo-o-p-p-s-s

Old Timers' Disease strikes again!

You are, of course, absolutely right, Jim.

-- Edited by Rolly on Friday 12th of November 2010 04:56:24 PM

Don't tell me that! It'll go to my head! wink