Steering Problems (1 Viewer)

Kensmith314

Free Member
Mar 18, 2015
40
52
Shropshire
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35,479
MH
Knaus Sky Ti
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Almost a year
Hello everyone,
I am very new to motorhoming - 9 weeks and counting.
My name is Ken and my wife is carol.
So far we have toured the UK for 9 weeks and have just returned from Cornwall - a truly lovely place.
I have one problem and would really appreciate any advice.
My motorhome is a Knaus Sky Ti on a Fiat Ducato 130 chassis.
It is two years old and 'as new' in every respect.
I bought from a lovely couple who advertised it on this forum.
My problem is in driving it on motorways.
The steering is extremely light and I have to really concentrate on keeping it in a straight line.
On the M5 this morning, on some stretches of concreted motorway it was drifting all over the place and I had to reduce speed to 45 mph just to have any control.
I can never go above 60 mph because it seems so unstable.
Any help or advice, please, would be very welcome.
 

pappajohn

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Aug 26, 2007
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Some motorways, usually those with poor or overdue maintenance, are badly rutted by HGV's.
Their wheel track is obviously wider than that of a light commercial chassis so you tend to hop from one rut to the other which gives the impression of instability.
Try driving closer to the shoulder or lane dividing lines to get away from the ruts and see if that helps.

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gozomike

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My first check would be the tyre pressures. Also is there any free movement turning the steering wheel gently where the road wheels do not turn sideways.
 

DBK

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Jan 9, 2013
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Could be tracking, ie toe in/out but as suggested take it to a garage. Although only two years old it might have hit a pothole or curb and bent something.

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Kensmith314

Free Member
Mar 18, 2015
40
52
Shropshire
Funster No
35,479
MH
Knaus Sky Ti
Exp
Almost a year
Thanks for the amazingly quick replies.
The try pressures are 58 psi at the front and 73 psi at the rear.
There doesn't seem to be any play in the steering wheel.
But, when I got in my car this afternoon after driving 330 miles in the motorhome the difference was pronounced.
In the car I can just relax and the steering takes care of itself, almost.
The steering wheel in the car wants to be in the central position as you drive.
In the Knaus, it is so light in the steering I have to concentrate all the time.
Straight to a garage, as already advised?
A final question?
Should I be able to drive it at 70 mph in comfort?
Thanks.
 

DBK

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Jan 9, 2013
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Thanks for the amazingly quick replies.
The try pressures are 58 psi at the front and 73 psi at the rear.
There doesn't seem to be any play in the steering wheel.
But, when I got in my car this afternoon after driving 330 miles in the motorhome the difference was pronounced.
In the car I can just relax and the steering takes care of itself, almost.
The steering wheel in the car wants to be in the central position as you drive.
In the Knaus, it is so light in the steering I have to concentrate all the time.
Straight to a garage, as already advised?
A final question?
Should I be able to drive it at 70 mph in comfort?
Thanks.
Yes to the last question.

A cheaper answer to the penultimate question would be to take it to a good tyre place and check wheel alignment but if something is more seriously bent they may not pick it up. You need to ask if they can check the castor angle - which is the thing which makes the steering self-centered, which is what is missing.

Tyre pressures are a subject in themselves. The only sure way is to take the MH to a weighbridge and find out the axle weights. Then consult the tyre manufacturer for the recommended pressure for that load. The handbook can be misleading.
 
Last edited:

motorhomer

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May 17, 2008
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since 2005 (but 30 years caravanning)
Is 58 psi as recommended for this van? Sounds low to me. Mine runs at 65 front and 73 rear, and previous vans have been more. That said, yes you should be able to cruise comfortably at 70. The steering IS light, however.

But I would get it checked.

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R

Robert Clark

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You may need to go to a commercial tyre depot. ATS Euromaster have a number of branches that do large and heavy vehicles
 

jollyrodger

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And the other thing in line with all the above are ALL the wheel nuts tight ,and wheels running true ?
 
Jul 29, 2013
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Have you checked you weight and loading?it sounds like you are heavy on rear making steering light.
Worth going to a weighbridge before garage only cost a few quid .

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Kensmith314

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Mar 18, 2015
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52
Shropshire
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35,479
MH
Knaus Sky Ti
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Almost a year
Thank you all very much for your replies.
Because it is such a safety issue I will take it to my usual garage as soon as I can book it in.
Because it is the one and only motorhome I have ever driven I couldn't be totally sure that this is just how they are.
However, the number that have passed me in the last 9 weeks made me realise that there probably is something wrong with the Knaus.
Thanks, everyone.
Ken
 
Feb 16, 2013
19,513
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uttoxeter
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ambulance conversion
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50 years
One thing, was it windy?, hell of a different thing to drive than a car in wind especially if overtaking lorrys or being overtaken.
Just seen your last post saying you were being overtaken. Could well be the problem if you have no experience of driving high sided vehicles.
 
Jul 29, 2013
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Please let us know how you get on and what you discover.
Hope it's not too costly

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Kensmith314

Free Member
Mar 18, 2015
40
52
Shropshire
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35,479
MH
Knaus Sky Ti
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Almost a year
Hello Chaser,
No, no wind at all.
The problems are all to do with lightness of steering and no self-centreing.
I tend to drive a car with one hand (I know I shouldn't) but daren't drive this with one hand.
And wouldn't ever risk going over 60 mph.
I've done over 2000 miles now and it isn't getting any better.
 
Sep 23, 2013
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Yours does sound an extreme case & it's worth getting it checked. But be aware that the Ducato steering is always horribly light & with a tendency to wander. It is the worst thing about an otherwise lovely drive. Also rather vague around the straight ahead position if you are used to a good car setup.
 

TheBig1

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could be a few things as already stated. get a garage to check it thoroughly. I had similar years back with a new 4x4, the steering was super sensitive and wouldn't re-centre. that was diagnosed as faulty power steering rack

as for the draught of other big vehicles on the motorway destabilising the steering, consider fitting airbags on the rear suspension. they help massively

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Kensmith314

Free Member
Mar 18, 2015
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52
Shropshire
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35,479
MH
Knaus Sky Ti
Exp
Almost a year
Thanks for your reply, TheCaller.
What you describe does sound like what I am experiencing.
Surely I should be able to go over 65mph, though, shouldn't I?
 
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Kensmith314

Free Member
Mar 18, 2015
40
52
Shropshire
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35,479
MH
Knaus Sky Ti
Exp
Almost a year
Thanks, TheBig1.
My first resort will be my local garage.
They are very trustworthy but I'm not sure they do commercial type vehicles.
If they don't, I'm sure I can find a garage that can help.
I will fix the issue one way another and post the outcome on this thread.
 

Allanm

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Jun 30, 2013
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You should be able to drive it comfortably up to and over the speed limit. Got mine up to almost 90 ( as shown on the satnav) and it was steady as a rock. Whether you would want to drive it that fast regularly is another thing. Fuel consumption will plummet.......

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RS_rob

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Dec 14, 2013
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sounds like tracking or weight positioning, I drive big trucks & as everyday is a different truck I am faced with this issue every day.
Get the tracking checked & consider the positioning of all your items inside.
 

Jaws

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Sep 26, 2008
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I would say it has quite possibly been set up with zero toe in..
That would make the thing wander and the steering become overly sensitive.. in fact making it feel very light indeed
A certain amount of toe in is required to assist with the castor effect .. No toe in means it will go where it feels like rather than in a straight line !

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treetops1

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Feb 25, 2013
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I think you have too much weight on the rear end ,Get it weighed as soon as .You may find you have to distribute some of the gear you are carrying .Cheers.H
 
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Kensmith314

Free Member
Mar 18, 2015
40
52
Shropshire
Funster No
35,479
MH
Knaus Sky Ti
Exp
Almost a year
Hello Jaws and treetops1.
Thank you for these replies.
I rang a local light commercial garage this morning and have booked it in for Wednesday.
When I explained the problem he said they can check wheel alignment and caster angle and everything else.
They will also have someone go out in the van to check whether it is just me and my incompetence.
 
Sep 23, 2013
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Thanks for your reply, TheCaller.
What you describe does sound like what I am experiencing.
Surely I should be able to go over 65mph, though, shouldn't I?
I would have thought so.

Yours is a coachbuilt & mine is a PVC, so you have a larger area for the wind to act on & more rear overhang, so more potential for weight transfer if you have much stuff loaded behind the rear axle.

Mine doesn't get noticeably worse with speed & I'm certainly happy to do more than 65mph on a motorway if I need to get somewhere. 'Happy' is probably the wrong word, but more because of the effect on fuel consumption rather than any steering problem!

If the steering checks out ok for play & alignment, the next step would be tyre pressures & load distribution. Load as for a holiday & check the total vehicle weights & the individual axle weights at your local weighbridge. Remember that for the individual weights, you need a weighbridge with a level run off area so the van stays level with only one axle on the bridge.

It might be worth checking both loaded & unloaded. If the front axle weight goes down when loaded, you have a load distribution problem that needs to be addressed. :D

Once you have the weights, you can look up the correct type pressures for your tyre make & size. I have a copy of the Continental data sheets, but most manufacturers will respond to an email (although I think someone said that Michelin refer you to the vehicle manufacturer).

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Kensmith314

Free Member
Mar 18, 2015
40
52
Shropshire
Funster No
35,479
MH
Knaus Sky Ti
Exp
Almost a year
Thanks, TheCaller.
I did take it to a weighbridge recently and it was well under the total limit.
It wasn't a weighbridge that could do individual axes, though.
However, in the rear garage all I haveare 2 folding bikes and a 16 kg kettlebell plus two lightweight chairs and a table. About 50 kg in all.
I don't have any bikes on the back of the Knaus which would be even worse, I think.
I have seen people with scooters on the back which are much heavier.
 
Jul 29, 2013
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Doesn't sound like much weight in garage but it could be elsewhere affecting back axle weight,I can't stress enough how important it is to get axle weights right as it affects balance of van
 

DBK

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Thanks, TheCaller.
I did take it to a weighbridge recently and it was well under the total limit.
It wasn't a weighbridge that could do individual axes, though.
However, in the rear garage all I haveare 2 folding bikes and a 16 kg kettlebell plus two lightweight chairs and a table. About 50 kg in all.
I don't have any bikes on the back of the Knaus which would be even worse, I think.
I have seen people with scooters on the back which are much heavier.
You don't need a special weighbridge to get axle weights. Just drive over it far enough so the front wheels are on it. Get the weight of this for the front axle then drive over it completely to get the total weight. Subtract the front weight from the total and you have the rear axle weight.

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