Merc Sprinter Seat Upgrade &Rear Suspension

Sat here ploughing through the Internet searching spring details, checking Daimler Benz RV Sprinters in the USA and Euro models here etc etc and thinking of all the collective time we have all put into this when I suddenly thought 'why oh why cannot Mercedes Germany (not just Merc dealers with their own interpretation of what is and what is not) just tell us what the part number of springs to spec C33 should be fitted to big'nuf's waggon????
. 

SIMPLES surely 

A case of:

'vorsprings durch mystique'?

I'll get me coat.....

Peter T
Hmmmm 
Just to clarify, He just said remove the DriveRite Semi Air Assist and revert to standard suspension.
It was me that presumed they had taken place of a coil spring...and it seems I was wrong.
As you say, it consists of two, double leaf springs, a pair of shock absorbers and a pair of rubber shock
absorbers (bump stops).
It is a mystery to me how he thinks it will interfere with the suspension software...if there isn't any?

All I know is, I have the correct springs, a pair of shocks and the semi air ride....and it handles awful....so Im desperate to sort it and thought that AS or Mercedes would know their stuff and advise me.

The AS gent was Dave Williams - (seemed helpful to me....but as I said, time will tell).

Is the Stanton fitted with an anti-sway bar at the rear?  if so, can it be upgraded?
If none fitted, is it possible to fit one?
I read another solution may be to upgrade to the 1 1/2" bar and fit Koni shock absorbers?...any thoughts?
Or shall I just shut up and find another interest? lol

Just get the correct springs like the rest of us have and all will be well . I am sure it is getting over complicated and hopefully will be sorted without the addition of gizmo's and springs and airbags etc.

big_nuf, does your build spec include option C43, Higher capacity rear stabiliser?

The higher-capacity stabilizer has a larger diameter than the standard version. The stabilizer is fitted behind the axle and attached at two points to the axle tube and at two points to the frame. It is a torsion bar made of spring steel and is fitted transversely to the direction of travel and parallel to the axle. It only exerts its stabilizing effect under unilateral compression.If there is equal compression on both sides, the stabilizer has no effect


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I am sure half if not all the problem is the springs are too soft which is why it is almost sat on the axle and needed airbags in the first place. Good point about the rear stab though.

Ploughlin....Yes I have C43 - Rear Axle Stabilizer Reinforced lower Frame. (thank you for pointing this out) [You must be registered and logged in to see this image.] 

Jaytree...I seem to have the correct springs as confirmed by Mercedes Benz (as discussed yesterday)...but just to get even further confirmation, I am having them checked by AS too.
How can they become soft in just 4 years and 5000 miles?....(not saying you may not be right though?)

And I also agree with you, I don't really want to be spending money and wasting time adding all the gizmos for the sake of it....I just want a van that's safe to drive...

Nutter on our bus?

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Jaytee wrote:I am sure half if not all the problem is the springs are too soft which is why it is almost sat on the axle and needed airbags in the first place. Good point about the rear stab though.

Sorry Big'nuf, wrong terminology for soft read 'wrong springs'. As I mentioned before the advised 'correct' spring PT # you were given appears to be just std sprinter springs.  Anyway, lets see what happens at AS. BUT they must ask Merc Germany what PT # should be on for C33 not just another Merc franchise. What have other Stantons got fitted? Need this basic query sorted before any other 'remedies' me thinks.
JT over and out 

The conclusion I came to, some while back, is that the M-B chassis/cab i.e. tipper truck and the chassis/cowl, which is what we all have, potentially carry similar loads yet the suspension components fitted are different. My M-B contacts tell me that this is because the motor-home constructors asked for this "luxury", perhaps in the mistaken belief that we fogeys all like to wallow and roll about on soft suspension; while the tipper guys get an industrial suspension designed to do a job.
 

Any news Big'nuf? Did you run the weighbridge?

I have enlisted the aid of someone on the US Sprinter Forum.

He has confirmed that with Option C33 and XL8 (weight upgrade to 3880kg) MB fit 906 320 34 06 ( single spring). Without XL8 they fit a twin spring 906 320 75 06 which is one of the spring options noted by big_nuf in his 4 april 8.25am post.

So it appears XL8 option gets different springs to staight C33 option.

No response from MB Milton Keynes (am I surprised?)

Well done Peter, good result, or is it? Why does he have a soggy bottom then? Would still be interesting to see what his axle weight is on the weighbridge cos if it is IRO the bigger vans with the single heavier spring then the specified springs on his are not man enough.

Just an update...
Drove to Cheddar on Friday with 2 bar in the air bags....awful ride...more like driving in tramlines as opposed to wallowy.

Spoke with a VB airbag supplier in Somerset, he backed up some of what AS recently told me...My van would not usually require any airbags and the back end WOULD sit very low, as designed and recommended by Mercedes and AS, but as I have Driverite semi air assist bags fitted they recommend only inflating them if carrying an unusual or exceptional load or inflate them for improving ground clearance when manoeuvring.
So I emptied all the air out of the bags, dropped the rear to its lowest position and drove home.....a different van !
No swaying or tram rut effect (just the usual side wind). Drove great even at 80...but a little bit hard over the smallest of bumps.
A result so far...
It is still booked into Marquis as AS kindly arranged so will keep you informed of spring situation.
I may even enquire if upgrading the shocks would ease the bumpiness...

Incidentally, the weights on the axle were pretty close, front being just under and rear being a fraction over making weight 3280kg.
(AS agreed it will be fine to 3500kg and are in the process of re plating it).
I removed some weight to get it spot on for the journey above.

So bottom line is: not really a problem at all 
What were your individual axle weights out of interest?