Air assisted rear suspension

Discussion in 'Tech/Mech General' started by Geoff 2110, Jun 10, 2014.

  1. Geoff 2110

    Geoff 2110 Funster

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    Hi new to this site and would like some advice. We have a 2002 Swift Sundance 630g on a Fiat Ducato 2.8jtd. We would like to fit rear air suspension, is it worth doing, if so which is the best one to fit
     
  2. Peter & Elaine

    Peter & Elaine Funster

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    In my humble opinion yes
    Why well a few reasons I prefer it
    Better handling into corners
    The ride height can be lifted by increasing pressure giving more ground clearance at rear this will give better load transfer from rear to front so keeping axel loadings more balanced and in soft ground blowing it up to max pressure put more weight on front axel giving far more traction
    When running fully loaded its a far better ride no rear axel hitting bump stops
    When loaded to max Headlights will not be shinning up so it looks like you are on full beam
    This one is purely my opinion if air suspension is set to correct pressure when loaded it puts less stress on side walls of rear tyres
    As for setting pressures to start with it's all trail and error till you find the right set up for you

    We now run at
    30 psi light load (weekending)
    40 to 50 psi med load a(a week away)
    50 to 60 max load (2 /3 weeks away)
    80 psi when running over loaded (3 months in morocco Elaine's shoes and wine enough food for a army full water tanks and my booze )

    It totally changed our van and I consider it money well spent £450 or there a outs

    Plus when running grossly overloaded like most of us do at some time it levels van out so local plod and VOSA can tell at a glance

    But don't listen to me I talk bull and no one listens anyway

    Do it
     
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  3. TheBig1

    TheBig1 Funster Life Member

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    I recommend the kit from marcle leisure for under £500. will take any mechanic an hour to fit. makes a huge difference to the drivability of a motorhome
     
  4. Trikeman

    Trikeman Read Only Funster

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    Second Big1s recommendation - fitted myself and it's superb, just wish I did it long ago.
    Go for it for all the above reasons.

    Trikeman. :Wink:
     
  5. dave newell lvs

    dave newell lvs Trader-Vehicle Services

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    Sorry to disagree but there are a couple of glaring errors in your statements:

    " The ride height can be lifted by increasing pressure giving more ground clearance at rear this will give better load transfer from rear to front so keeping axel loadings more balanced and in soft ground blowing it up to max pressure put more weight on front axel giving far more traction"

    Increasing the rear ride height will not affect load transfer and will not improve front traction at all!

    "This one is purely my opinion if air suspension is set to correct pressure when loaded it puts less stress on side walls of rear tyres"

    The load on the tyre sidewalls is purely the mass of the vehicle resting on those tyres, altering ride height or changing suspension systems does not alter the mass of the vehicle so the load on the tyres sidewalls is exactly the same. Air suspension can reduce impact loadings slightly though, such as when driving over potholes by allowing more compliance in axle movement.

    D.
     
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  6. DavidG58

    DavidG58 Funster

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    We have what I presume to be the simplest possible system, it was already fitted when we got out current MH, so I can't give any feedback on before / after

    I needs a compressor attaching to individual valves one for each side in the cab, we carry a 12V air pump which does the job, I have tried running at various different pressures and can't tell the difference between them

    If I was fitting from new for myself I would prefer an automatic system, (built in compressor at least) but don't know how much more that would add to the price

    On rough ground we suffer quite violent left to right rocking when moving, not sure if this is a function of the air suspension

    I have a theory that once someone has spent a big lump of money on something they are typically always full of praise for it, so as not to feel bad about wasting money.

    But I would (probably will) upgrade mine to a more automatic version which I hope will self level when pitched, within reason

    Opinion only of course, do not invest or not on my word
     
  7. DuxDeluxe

    DuxDeluxe Funster Life Member

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    I'm just awaiting delivery of a Dunlop air assist kit so that I can uprate the vehicle to 3850 kg. When speaking with SV tech they suggested I save my money and use just the basic system as once set nearly all people don't adjust it very much.
     
  8. Bellini

    Bellini Funster

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    I've just ordered the full moo from Conrad Anderson for Udo's rear end.

    The one thing I've asked for (not confirmed as yet) is an air tank coupled to an external air line for MH tyres, bike tyres, etc.

    I don't know if having in-cab controls are a good thing or not, but my decision was based on, say, driving along a motorway and feeling the need to stop and manually inflate the 'bags for added stability.

    Time will tell if having air assist proves worthwhile or not. It had better be!!!
     
  9. Mr Colpot

    Mr Colpot Funster

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    We are having the Dunlop kit from Marcle fitted to our M/Home today so we can uprate the rear axle by 100kgs. I know it doesn't sound a lot but it will make the Motorhome useable as the rear axle had only 10kg spare when in running mode and we will uprate from 3000kg to 3300kg once done.
     
  10. Jez and Lin

    Jez and Lin Funster Life Member

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    Are there any recommended pressures for air suspension. I put about 20 psi in mine but that's not based on anything scientific other than the Van tends to crash down over potholes, level crossings etc at anything higher. I have read that air suspension is an advantage on older MH's where the suspension springs and shockers are getting a bit tired therefore acting as an assist to them.
     
  11. DuxDeluxe

    DuxDeluxe Funster Life Member

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    Trial and error was the advice that I got...... Will try about 20 -30 psi first when I get around to fitting it
     
  12. SUGGY

    SUGGY Funster Life Member

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    Rosie and I have just fitted the Marcle Units ( Dunlop ) ,:thumb:

    Really good informative service " EXCELLENT " , from them .:BigGrin:

    ( Can we get Funster Discount set up Jim ? :BigGrin: )

    For our , 7 meter, 3500kg Transit based Fendt £ 514, including the gauge unit with the Left / Right filler taps .( fitted quotes by various companies were around £700 )

    It took around 4 hours , (jacking , packing , decipering the drawings :Doh:, etc )of crawling around under the MH ,and a week to get over it :Rofl1:

    We ran the air pipes in hose pipe from the rear axle into the cab and across the chassis of the van between the 2 units ,

    The gauge unit is mounted on the door pillar behind the driving seat so it can be filled from inside the MH , ( Rosie has been trained to do this :Cool:)

    We also fitted a 12 volt socket behind the seat to plug the compressor in and also use it for phone charger etc ,

    The ride is definately a lot lot better and more stable , :Cool:

    Virtually no rock when passed by large container lorries ,
    dose not seesaw on undulating roads / tracks, so traction is better
    dose not rock n roll when getting in / out of the van / moving around

    from zero to 10 psi the tow bar went up 2 inches
    each 10 psi after lifts the tow bar by 1/2 inch

    We are running at 40 psi ( see pete n Elaine post ) :thumb:
    we were with P n E in Morocco and his ability to vary the suspension was really usefull
    and gave us a good insite as to its use ,prompting us to buy ours ,

    Our units fit to the axle about 6 inches in from the spring (some mount on top of the spring ),
    so it does not make much hight difference on filling the left / right bellows for leveling :Doh:

    Hope this Helps :RollEyes:
    Graham
     
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  13. Peter & Elaine

    Peter & Elaine Funster

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    As I quoted I know nothing
    So we will agree to disagree
    45 years in plant and transport as a fitter and heavy haul driver shot
    O well
     
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  14. Geoff 2110

    Geoff 2110 Funster

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    Thank you

    Thanks for the comments .............. time to get it fitted
     
  15. DLT

    DLT Funster

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    air suspension

    Hi Geoff 2110
    Have P.M. you. cutfinger
     
  16. Trikeman

    Trikeman Read Only Funster

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    Geoff, you won't regret it for sure.

    On our set-up (Ducato 2.8, 7.4 meter 6 berth Autotrail Apache SE) we have, after much experimenting, settled on 45 psi as our loaded 'running' pressure. At that we find little or no truck/coach buffeting on motorways, cornering especially on roundabouts is at another dimension (superb), towing greatly improved due to much more stability/height and the ability to level off once parked is superb - also as quoted, a good by-product is the reduced 'rocking' when parked up. The ability to lift or lower the rear is a great bonus for ferry and steep 'drive' inclines too. Went to a wedding in ours recently and the sudden incline to the venue (stately home) would have normally prevented us getting in, but a few more psi, up she went and in we go.
    :thumb:

    Long after the impact of the cost has been forgotten, the quality of the ride and additional benefits can be enjoyed for years - you will wonder how you ever managed before and if you buy a similar MoHo later you can transfer it too.
    :BigGrin:

    Good luck with it.

    Regards,

    Trikeman. :Wink:
     
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  17. Peter & Elaine

    Peter & Elaine Funster

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    Air springs used for rear suspension applications are designed to enhance the handling performance and stability of your vehicle by supplementing your vehicle's existing suspension system.

    Benefits:
    Levels vehicle when you are hauling heavy loads
    Increases front wheel traction, improving steering and vehicle balance
    Levels headlights, thereby increasing visibility
    Enhances braking and handling, even in adverse road conditions
    Can be adjusted to accommodate varying loads
    Reduces rear-tire wear

    Reduces stress resulting from extra weight on vehicle's rear suspension
    Reduces rear vehicle sag
    Provides an additional contact point for suspension system, distributing the load evenly

    Provides additional vehicle stability
    Enhances the ride of the vehicle
    Prevents bottoming out
    Adjustable springs can be individually inflated to balance out and redistribute uneven vehicle loads

    Types of Kits Used in Rear Applications


    From firestone site

    Oooooopppppssss I know nothing
     
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  18. funflair

    funflair Funster Life Member

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    I think the bit of your original post that was most misleading was the statement about transferring load from the rear to the front, and to be fair that is not backed up by your quote from Firestone. It is simple mechanics and you would need to raise the rear a few metres not a few centimetres to have this affect.

    Martin
     
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  19. knokinonabit

    knokinonabit Funster

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    Quick question

    Does anyone know/think that fitting air suspension to a tag axle MH would have any benefit, apart from being able to raise and lower the vehicle ?
     
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