Raw40 Posted August 6, 2019 Share Posted August 6, 2019 Hi everyone. I have a 2016 Autotrail Imala 615 motorhome based on the Fiat Ducato chassis cab. This is our first motorhome, picked it up last weekend. It has a vibration which can be felt through the steering wheel and chassis/cab it seems to be dependant on speed,20-70MPH and road surface I.E perfect tarmac vibration is less, normal UK road surface, concrete road, vibration is unbearable the only way I can describe it, it’s as if there are solid tyres on the vehicle which creates a high frequency vibration. I am in the process of getting my tyres , Michelin Agilis camping, checked and balanced just in case there is a problem with damage to any of them. Has anybody else experienced similar issues. Link to comment Share on other sites More sharing options...
Sydney1 Posted August 6, 2019 Share Posted August 6, 2019 Probably a missing or lose wheel weight which will be rectified when balanced although does not account for different experience on different surfaces. Good luck with sorting Link to comment Share on other sites More sharing options...
Robinhood Posted August 6, 2019 Share Posted August 6, 2019 If your "new" van has been passed to you with tyre pressures set to the recommended values (in the region of 80psi all round) then any issue with balance, etc. may well be exacerbated by the hard ride this produces. Indeed, if you aren't used to driving a motorhome, it may simply be this "normal" hard ride that you are experiencing. Nowadays, Michelin will not officially recommend lower pressures for their "camping" tyres for the rear, though they often will for the front (based on actual load). Continental, however, still appear to publish tables for their "Camping" tyres that provide lower pressures for given axle weights, and many have chosen to reference these, and reduce pressures accordingly (even for Michelin tyres). Given Michelin's current practice, it patently is a personal decision as to whether you choose to reduce the pressures. I will say that I do (and have over a number of 'vans, back to the day when Michelin first introduced "Camping" tyres, and would, at that time, quote axle-load related pressures) resulting in a significantly more compliant ride. I do, however, make sure I know the maximum axle loads at which I travel, know that neither axle is overloaded, and also that weight distribution gives a significant margin on each - even then I allow an uplift before taking pressures from the Continental tables. Link to comment Share on other sites More sharing options...
BruceM Posted August 6, 2019 Share Posted August 6, 2019 I’d agree with other posters, most probably the wheels at the front need balancing. If it’s not that I’d suspect a wheel bearing especially if gets worse the faster you drive. On such a young van a failing wheel bearing would seem unusual although if it’s high mileage I guess that it’s possible. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted August 6, 2019 Share Posted August 6, 2019 Vibration at the steering wheel due solely to wheel imbalance is unlikely to be exhibited at a speed as low as 20mph and the characteristics of imbalance ‘shake’ at the steering wheel’s rim are normally as shown on this YouTube video If the front tyres of Raw40’s 2016 Auto-Trail have been recently replaced, or the rear wheels were recently swapped to the front axle, then the possibility of imbalance becomes more likely. Otherwise there may be a physical fault with one (or both) of the front tyres. Personally, If the front tyres are inflated to a high pressure (the usual recommendation would be 72.5 psi for a 2016 Ducato with 15”-diameter wheels, 80psi if the wheels are 16”-diameter) I’d lower the pressure to 60psi as an experiment to see what, if any, effect that might have on the vibration. But as the Imala’s wheels/tyres are to be checked and rebalanced, that’s the sensible thing to do first. My 2015 Ducato-based Rapido motorhome has 15”-diameter wheels shod with Michelin Agilis Camping 215/70 R15CP tyres. The recommended front-tyre pressure is the usual 5.0bar/72.5psi, but I use 4.5bar/65psi (and 5.0bar/72.5psi for the rear tyres rather than the recommended 5.5bar/80psi). Using the recommended pressures I found the Rapido’s ride very harsh on the UK’s poorly maintained roads and, although the motorhome’s ride is still pretty firm, it no longer shakes one’s fillings loose. However, whatever the tyre pressures have been, there has been no wheel imbalance symptoms. Link to comment Share on other sites More sharing options...
flicka Posted August 6, 2019 Share Posted August 6, 2019 If the motorhome has been stood for a period of time, it could also be that the weight on the front wheels has caused a flat spot on each of the tyres. This would be noticeable at almost any speed. Link to comment Share on other sites More sharing options...
Kennyd Posted August 7, 2019 Share Posted August 7, 2019 I used to get similar on my vans when a tyre goes out of shape , at low speeds you can almost feel the van Rocking slightly , To check if tyre is warped jack it up and spin the wheel & it’s usually visible Link to comment Share on other sites More sharing options...
Paul- Posted August 7, 2019 Share Posted August 7, 2019 Another one which can cause a problem is if its if its had a pre-sealant in the tyre too much has been added. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted August 7, 2019 Share Posted August 7, 2019 flicka - 2019-08-06 9:19 PM If the motorhome has been stood for a period of time, it could also be that the weight on the front wheels has caused a flat spot on each of the tyres. This would be noticeable at almost any speed. The ‘flat spotting’ phenomenon is described here: https://www.continental-tyres.co.uk/car/all-about-tyres/tyre-damages/flat-spotting Link to comment Share on other sites More sharing options...
Raw40 Posted August 7, 2019 Author Share Posted August 7, 2019 Thank you all for the in depth replies, I'm having the checks done tomorrow and will report back on the outcome. I have checked the pressures myself and as stated they are set at 5 and 5.5 bar did wonder if the high pressures where playing a part in the issue I'm experiencing. Link to comment Share on other sites More sharing options...
BruceM Posted August 7, 2019 Share Posted August 7, 2019 Raw40 - 2019-08-07 9:12 AM Thank you all for the in depth replies, I'm having the checks done tomorrow and will report back on the outcome. I have checked the pressures myself and as stated they are set at 5 and 5.5 bar did wonder if the high pressures where playing a part in the issue I'm experiencing. For what it’s worth I run my van tyre pressures at 4.5 bar (cold – about 4.9 bar when warmed up) – ie Dethleffs’s recommended pressure for my tyre type and size. I don't experience any steering shake or vibration; it feels just as smooth as driving a car. The van body, on the other hand, does noisily shake on rough road surfaces, the worst being that southern section of the M25 where it’s concreted and has the worn expansion gaps. Mind you, that’s noisy even in the car. Link to comment Share on other sites More sharing options...
Sydney1 Posted August 7, 2019 Share Posted August 7, 2019 BruceM - 2019-08-07 10:23 AM ...... the worst being that southern section of the M25 where it’s concreted and has the worn expansion gaps. Mind you, that’s noisy even in the car. I hate that particular bit but have to use it almost every time we go out in the van. It really is poor Link to comment Share on other sites More sharing options...
goldi Posted August 7, 2019 Share Posted August 7, 2019 Good afternoon, Make sure your nuts are tight. Link to comment Share on other sites More sharing options...
Raw40 Posted August 9, 2019 Author Share Posted August 9, 2019 Had the work carried out yesterday, tracking and balancing has cured the vibration through the steering wheel and the slight pull to the nearside. There were no issues with the tyres they are all in good condition I have also reduced the tyre pressures to 65psi front and 70psi on the rear which has made a noticeable difference to the road noise and feedback from different surfaces. There is still a very slight vibration noticeable through the chassis /body the easiest way to describe it is in the past when I’ve been travelling on a section of road where there are roadworks being carried out and a tracked vehicle, caterpillar, has been driven on the surface you can feel the mark left on the road, hope that makes sense. Link to comment Share on other sites More sharing options...
BruceM Posted August 9, 2019 Share Posted August 9, 2019 This might assist https://www.dowleys.co.uk/blog/why-might-your-vehicles-steering-be-pulling-one-side/ Link to comment Share on other sites More sharing options...
Derek Uzzell Posted August 10, 2019 Share Posted August 10, 2019 Raw40 - 2019-08-09 2:08 PM ...I have also reduced the tyre pressures to 65psi front and 70psi on the rear which has made a noticeable difference to the road noise and feedback from different surfaces... It would be worth you confirming via a weighbridge what your Imala’s axle-loadings are when it is in fully loaded ‘holiday’ trim. I've attached below a couple of images from Continental’s technical handbook. These relate to a 215/70 R15CP 109 tyre (which I’m guessing is the specification of your Michelin “Agilis Camping” tyres) and show inflation pressures from 3.0bar to 5.5bar and the related axle-loadings in kg. You’ll note that there are two lines of axle-loadings - the top one for the front axle (FA S = Front Axle Single-wheel configuration) and the lower one for the rear axle ((RA S = Rear Axle Single-wheel configuration) By having the motorhome weighed you MIGHT find that you can safely reduce the 65psi(front) or 70psi(rear) pressures somewhat to further improve the ride quality. It’s OK to judiciously reduce tyre pressures as a temporary experiment, but risky if the selected pressures are to be used long-term and ‘fully loaded’ axle-loadings are an unknown quantity. Link to comment Share on other sites More sharing options...
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