Hope that if your tow truck was fitted with an incompatible tow ball that the insurance assessor doesnt count that against your claim. Be interested to know the outcome.
I have to say I a not convinced by the suggestion that a non ALKO compatible tow ball is the problem but it is a possible cause. We used a none compatible one for several years before the dealer pointed it out when the caravan was in for a service, and had had no problem. I know it is in the advice given but I have never heard of this problem with a none compatible one and cannot see that it would cause the caravan to become detached, rather it might damage the towing vehicle.
The accident is unusual as it occurred after a relatively long time and despite having negotiated a route that should have caused a detachment far earlier rather, than on a motorway which is generally far less likely to cause a problem. I suppose they could have hit a pothole but that is about all.
I have tried to check this from web sales and think it is not compatible, there is a second one costing over £100 which is described as stabiliser compatible which I suspect should have been fitted.
The accident is unusual as it occurred after a relatively long time and despite having negotiated a route that should have caused a detachment far earlier rather, than on a motorway which is generally far less likely to cause a problem. I suppose they could have hit a pothole but that is about all.
I have tried to check this from web sales and think it is not compatible, there is a second one costing over £100 which is described as stabiliser compatible which I suspect should have been fitted.
Like Raywood, I'm not convinced the problem is only down to the wrong towball.
It is certainly true that the Alko caravan hitch should be used with an Alko style ball, but the reason for the "Special " ball is to allow the hitch the required full range of articulation. The Alko hitch uses the standard EU 50mm diameter ball, the main difference is the diameter and length of the stem that supports the ball. There should be no problem if a hitch is not taken to the limits of articulation and under normal driving conditions that could well be the case, but of course that might beyond the ability of a driver to avoid.
It is of course a concern that DW1311 has experienced a dislocation, and something of a mystery that it waited until it was on a fast road, which is unlikely to have twists and bends that might have over articulated the hitch and loosened it.
Its far more likely either the hitch was not properly engaged before the journey started or at some point during the journey the hitch was over articulated which has loosened it.
Because large articulations would be done at low speed, the hitch may have remained in contact with the ball, but as speed increased on faster roads the wind pressure on the front of the caravan may have been enough to reduce the hitches downward pressure enough to allow it to dislocate.
I note the OP's partner has HGV experience, and whilst I would expect such a person would be perhaps more aware of the need for care when hitching, but ball hitches are rarely used in commercial HGV trailers, so it might have been a new experience, and thus may not have fully understood the process.
I also note the incident involved a pick up truck. This raises the possibility the tow ball height may not have been within the 350 to 420mm height range, and the vibrations through the vehicles chassis may have had some adverse affect on the security of the hitch.
This is of course all speculation.
It is certainly true that the Alko caravan hitch should be used with an Alko style ball, but the reason for the "Special " ball is to allow the hitch the required full range of articulation. The Alko hitch uses the standard EU 50mm diameter ball, the main difference is the diameter and length of the stem that supports the ball. There should be no problem if a hitch is not taken to the limits of articulation and under normal driving conditions that could well be the case, but of course that might beyond the ability of a driver to avoid.
It is of course a concern that DW1311 has experienced a dislocation, and something of a mystery that it waited until it was on a fast road, which is unlikely to have twists and bends that might have over articulated the hitch and loosened it.
Its far more likely either the hitch was not properly engaged before the journey started or at some point during the journey the hitch was over articulated which has loosened it.
Because large articulations would be done at low speed, the hitch may have remained in contact with the ball, but as speed increased on faster roads the wind pressure on the front of the caravan may have been enough to reduce the hitches downward pressure enough to allow it to dislocate.
I note the OP's partner has HGV experience, and whilst I would expect such a person would be perhaps more aware of the need for care when hitching, but ball hitches are rarely used in commercial HGV trailers, so it might have been a new experience, and thus may not have fully understood the process.
I also note the incident involved a pick up truck. This raises the possibility the tow ball height may not have been within the 350 to 420mm height range, and the vibrations through the vehicles chassis may have had some adverse affect on the security of the hitch.
This is of course all speculation.
Damian
Moderator
I dont speculate, I go on facts and the fact is that I have had to change several Al-Ko hitches due to the wrong towball being used.
It may not happen immediately but with each journey the hitch hits the ball supportand causes damage eventually leading to the kind of failure as posted about, and it is only when examined in detail that it can be seen that the issue has been getting worse with each time the hitch has been used with the standard towball.
It may not happen immediately but with each journey the hitch hits the ball supportand causes damage eventually leading to the kind of failure as posted about, and it is only when examined in detail that it can be seen that the issue has been getting worse with each time the hitch has been used with the standard towball.
I don't quite see why towball height should be a possible cause of detachment, unless it was obviously and excessively outside tolerances.
Having said that, last year I experienced caravan detachment myself, albeit with a Winterhoff hitch. The cause was traced back to the hitch not being fully seated on the towball when the lever was pushed down. I did notice that the force required to operate the lever was abnormally high, but at the time I thought no further about it. What actually happened was that by forcing the lever down actually lifted the hitch off the towball again. The detachment happened while negotiating a bend only a few hundred yards after leaving the campsite and at relatively low speed. The brake cable did its job and so no damage was done and I could continue my journey after rehitching properly.
Having said that, last year I experienced caravan detachment myself, albeit with a Winterhoff hitch. The cause was traced back to the hitch not being fully seated on the towball when the lever was pushed down. I did notice that the force required to operate the lever was abnormally high, but at the time I thought no further about it. What actually happened was that by forcing the lever down actually lifted the hitch off the towball again. The detachment happened while negotiating a bend only a few hundred yards after leaving the campsite and at relatively low speed. The brake cable did its job and so no damage was done and I could continue my journey after rehitching properly.
Damian
Moderator
It makes no difference if there are or not.
It does not need severe anything, the van moves quite alarmingly when being towed and even in good conditions it still moves about a lot and if the wheels are not balanced it jumps around like a demented rabbit !!
The Al-KO hitch is best performing with a level hitch to car attitiude, raise the towball height and the clearance between the back of the hitch and the towball is reduced.
Lower the towball and the clearance at the front of the hitch is reduced, which is why Al-Ko spent shed loads of money to research and produce the extended neck towball.
The same issues do not seem to affect Winterhoff hitches which will sit very comfortably on a standard towball.
Hi he drives HGVs but tows a variety of different size trailers not relating to HGVs behind the same pick up and has never had an issue, he’s got over 30 years experience towing.
Damian
Moderator
Nobody is doubting your husbands credentials regarding towing but I expect that all the other trailers he has dragged behind the vehicle had the basic greased coupling or the eye.
A caravan is a different beast and does everything to throw you off balance and make you rethink your experiences.
With the introduction of stabiliser hitch heads they brought their own slant on towing and in particular, but not very well advertised, the need for a special towball for the Al-Ko hitch heads.
Unfortunately sales staff have very limited ability to inform buyers of what is actually required, whether deliberate or not, which is why a lot of things that should be mentioned are not at handover.
Having spoken to many HGV drivers, they all say that they would rather be driving a 40 tonne artic than a caravan !!!!
Parksy
Moderator
This is a Dixon-Bate pin and towball hitch.
There have been previous instances of caravans becoming detached from non- AlKo compatible towballs.
The green indicator has indicated that the hitch has locked but the caravan is only attached by the AlKo stabiliser rather than being properly hitched.
Past forum reports have shown that caravans have detached quite soon after the unit is moving so the O.P. was unlucky in this case.
The winding down of the jockey wheel to lift the rear of the towing vehicle is the best way to check that the hitch is correctly engaged as someone said earlier.
I hope that this unfortunate experience hasn't put you off DW 1311, nobody was hurt and hopefully the insurers will make things right for you.
Sorry I was informing one of the other members that my partner usually tows other trailers as they thought it was HGV trailers and as you say yes it is the usual greased coupling or the eye. Yes my partner has mentioned it’s much easier to reverse an HGV as opposed to a caravan although he’s managed easily enough lol.
It’s a pity it’s not well advertised about the special tow bar requirement especially with so many people buying caravans during the pandemic and I know there’s another member who’s commented on the thread that they tow with a pick up too. The insurance company did comment they’ve had so many recent claims due to detachments
Plan is to put a compatible tow bar on my car (that was the original plan but couldn’t get a tow bar fitted for weeks due to the volume of people requiring them) but now we know what we require and see what happens with the insurance - poor caravan has taken a bit of a bashing so I don’t think the outcome looks good. We will definitely do the jockey wheel test in future and no doubt will be a bit apprehensive on our first few trips. Really appreciate everyone taking the time to reply with your opinions and advice, it’s been extremely helpful. Thank you
It would require a really significant change in attitude for the clearance between the towball and the hitch to be reduced by enough to result in a foul condition. Industry standards call for 10 degrees of movement to be ensured up and down and that is a lot more than one would encounter in practice.
Thank you for that information. The mystery deepens, though Damian's revelation that he has changed several Alko Hithches due to abnormal wear associated with "standard" 50mm balls adds to the possible permutations.
DW, we have just the standard tow ball on our truck, not the ball and pin type, and is used for the caravan and a plant trailer, both so far with no problems - did 8 outtings last year. Will have a good look at it at the weekend when on flat ground to check height etc. The dealer at the time we brought ours asked us a similar question as another customer said the towball was 19" from the ground and too high for their caravan, although ours has always looked right. You are making me wonder now?
Ours is 'too high' when off but the dual rate suspension means the caravan drops the back of the Navara to a nigh on perfect level. Van looks dead level when attached.
Ours is higher than the measurement too now we’ve checked but would need to hitch caravan on to check level then and we always put the awning etc in the back of the pick up which would drop it. Caravan always looked level when hitched. Definitely worth researching as I would hate anybody to go through what we did on Friday night, it was terrifying.
I am confused by Parksy's suggestion that the green indicator may only mean that the stabiliser has engaged. The green indicator comes up before the stabiliser can be engaged, as you clamp this down after the hitch engages or am I missing something.
The green indicator is about 2mm only on mine, I think is used to be a bit more. Dealers said It was normal
John
John
I agree I had noticed the green indicator was smaller on this caravan than the last. I had been wondering if it was just me, but clearly not.
i have also noticed that the green indicator on mine was slighty smaller but had it checked by a dealer .
Pity they ever put the "green tell tale" on the hitch, it only leads to some believing it indicates a secured hitch, whilst at best it indicates the hitch is seated down onto the ball, not the ball is retained.
Jacking up the car's rear using the van's jockey system, is a far better indication the hitch can't be pulled off.
Jacking up the car's rear using the van's jockey system, is a far better indication the hitch can't be pulled off.
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