MERCEDES VARIO AIR SUSPENSION

[part time nomad]

I have found that my Mercedes Vario, rear suspension is a little bit low! and also a bit hard on the ride when you hit a big bump. There is not much travel in the rear springs, the difference between axle hanging (wheel not on ground) to sitting on ground (with empty water tanks) is only 45mm, although with the wheel on the ground the bump stop is still 95mm from the spring.

So my thinking is the springs have a heavy rating without much flex, so to improve the ride and introduce a bit of "bounce" I plan to insert an air bag, with adjustable pressure from in the cab.

I have done this for the front and it seems to work well, although I may modify the mounting to the spring.

with 2 bar pressure it lifts the vehicle and makes it more comfortable, also with the rear ones I will be able to lift the rear to give more ground clearance when needed.

I have made the brackets now and sent them away for plating.

 

[jostein]

Always interesting to see solutions like this, provide some pics of the install

 

[part time nomad]

This is the right hand side front air bag,
As you can see I had to reposition the reflex bump stop slightly further back, to make room for the air bag to be fitted close to the centre of the spring.

Originally the air bag was just on a saddle over the top spring leaf, but it moved about slightly when cornering, and you could hear it in the cab.
So I have just made a modification, that involved removing the `U` bolts and clamping a 3mm plate that is welded to the saddle between the top of the spring and the bump stop plate.

As you can see it is still work in progress as the `U` bolts are not yet tightened.

Right front spring

This is how the bottom was originally fitted

 

[part time nomad]

REAR SUSPENSION This is with the wheel removed and the axle hanging.



This is with the axle holding the weight of the vehicle, note the difference in the measurements.



Again this is with the axle hanging, but with the bump stop rubber removed.



With vehicle weight on axle, the reason for this exercise was to establish the space available.

 

[part time nomad]

This is the proposed position for the air bag!

[ATTTACH=CONFIG]406544[/ATTACH]

Viewed from the rear.



The difference between the fully compressed air bag and the bump stop rubber.



checking the amount of spare thread on the `U` bolts, to make sure there is enough to insert a 6mm plate on top of the spring.



I have cut the brackets out of 6mm plate and welded them up, but I have sent them away for plating so I can post them here yet, but I will as soon as I get them back.

 

[part time nomad]

To see the vehicle it is being fitted to "a new vario project"

http://forum.expeditionportal.com/threads/124365-A-new-vario-project

 

[tooFATtoDRIVE]

Excellent thread and source of info for future airbag fitting mods.

 

[part time nomad]

This is the modified bracket for lower front air bag mount, it clamps on top of the spring.



These are the brackets for the rear axle air bag top and bottom.

 

[part time nomad]

This is the o/s/r air bag now fitted

 

[part time nomad]

Here is the suspension air controller, the rear is inflated

 

[docka]

Thank you for this thread,, great info and something I may look into doing in the future

 

[ianc]

Here is the suspension air controller, the rear is inflated

Did you consider removing any of the spring leafs to make the suspension softer

 

[part time nomad]

Ian, I did consider it, but I don't think that it would be a good idea as it could fail mot. Also I think it may be hitting the bump stops all the time.

 

[ianc]

I carry about 2600kg on the front and about 2900kg at the back. I did some checking with a small camera on a very bumpy road. The front did occasionally bottom out with the new (Std 2800kg I think) spring fitted.
The rear never came close to bottoming out and this was further evidenced by the bump stops looking like they were rarely hit.

I'm pretty sure the MOT guys would not know how many springs there were in the rear set.

Edit: I just looked back at your photos and your rear bump stops don't look like they've been hit much either.

BTW - Can you tell me what bags you used on the rear?

 

[part time nomad]

You are right, I don't think it goes onto the bump stops, Initially I was apprehensive about removing them, but then seeing that they are not being hit decided it would be OK.

When you say about removing a spring leaf are you thinking about the "helper leaf" at the bottom ? Its worth a try, and there looks like there will be enough thread on the U bolts to save using spacers,

The only thing with removing a leaf it will make it ride lower on the back unless you fit a spacer block to replace the spring thickness.

I used Firestone air bags (224CZ) I took a template of the brackets !