Anyone with a Sprinter feeling helpful?

Well, law of sod prevails yet again. You will probably have seen my previous post re the rear spring failure and the successful replacement of both springs 

Driving too and from the NEC feeling generally bored on the M1 for ages the mind and eyes noted the steering wheel had to be at about 20deg to the right and if I let go (don't panic PC members it was only for a second   ) the vehicle drifted left. Hmmm, thought I, it didn't do that before the springs were replaced.

Anyway to cut a long story short, got underneath and did a quick measurement and the rear axle is twisted to the right by about 13 mm. Did some more measurements today and it appears they have fitted one spring 180 out I.e front is at back. If that is possible.

Would one of you please be able to measure the distance from the front face of the square axle mounting pad on the top of the axle where it is bolted to the spring by two U bolts to the centre of the front spring attach bolt head.

Don't need to be megga accurate I just want to know which side on mine is correct.

I have 674mm on the left and 687 on the right. 

Have a feeling the right is correct as the drop arm to the anti roll bar is vertical but that may not mean anything.

Many thanks

John

Can't really help you with that as ours is an SWB chassis with different type of springs. I have been involved in racing and sports-car suspension and chassis set up over the years and from what you describe your wheel-base on the left is now rather shorter than that on the right. It would be interesting to measure the distance between the wheel centres with a tape-rule on one side, compared to the other. The three-pointed badges should be useful for this and, obviously, you will need someone at the other end of the tape!
I find it incredible at a M-B dealership did not do full laser chassis checks after major work like removing both springs. Have you discussed it with them?

Pete Taylor wrote:Can't really help you with that as ours is an SWB chassis with different type of springs. I have been involved in racing and sports-car suspension and chassis set up over the years and from what you describe your wheel-base on the left is now rather shorter than that on the right. It would be interesting to measure the distance between the wheel centres with a tape-rule on one side, compared to the other. The three-pointed badges should be useful for this and, obviously, you will need someone at the other end of the tape!
I find it incredible at a M-B dealership did not do full laser chassis checks after major work like removing both springs. Have you discussed it with them?

Hi Pete,

Oh yes, deep discussions and its going back 'again' and some recompence will be needed if they have indeed fitted one spring a.se abut t.t. I am doing some more research to see if the springs can be fitted 180 about and if so then a lot of recompence

The thing that is 'really' concerning is that if I had not had some mechanical knowledge I would have taken what they told me as gospel which was ' Sir, the springs cannot be fitted incorrectly, it cannot be anything to do with what we have done and it will need the tracking adjusting'. My comment to that was 'absolute rubbish, there is nothing wrong with the tracking, it is something to do with what you have done, please put me through to your General Manager'. 

All good fun and I can feel a free service or two coming along

John,
I've been thinking about your chassis geometry: if the axle at the springs is effectively 13mm out of "alignment" (not exactly the correct word but you see what I mean) then at the centre-point of contact of the tyres this could easily be 20mm or more. No amount of tracking is going to correct that and the tyre wear would be even more horrendous than it must be at present- also the turn-in characteristics would be remarkably different on left and right lock. Perhaps even dangerous.

wrt fitting them back to front- there are several different leaf set-ups used on Sprinters the vintage of ours (don't ask me how I know this, it is not a pleasant story). There are: 1 leaf, 1 leaf heavy duty, 1+1 leaves, 2 leaf, 2 leaf heavy duty and 2+1 leaves. I think that is all of them(!) Some seem to have the wrap around for the bush the same orientation at both end and some have one "up" and one "down".
One thing I learned during my suspension saga is that A-S buy Euro-spec chassis/cowl vehicles at a cheaper rate than they can get on UK-spec ones, to the tune of about £1300 cheaper per chassis.
This also explains why A-S Sprinters are fitted with a steering wheel and dash computer not available from a UK M-B dealer (plus other stuff too), and in my case why, when I ordered the no-cost payload upgrade, I did not get the 2 leaf UK spring set-up but got a 1+1 leaf Euro axle set. Had my dealer ordered what I asked for, the vehicle would have been re-plated before it got to me and I would have been none the wiser. As he did not I uncovered a sorry kettle of worms, loads of excuses and some bluffers who did not understand what they were talking about. All sorted out now; van re-plated and fitted with semi-air Drive Rite suspension, cost split three ways between the dealer, A-S and myself. Apologies for thread hi-jack!

If you find the time please do let us know the difference in wheelbase side to side.

your more than welcome to have a look under mine to double check the measurements if you like i will be at knaresborough cc site next weekend

Thanks Duffie, Hoping to have it sorted by then. I am just doing as much research as I can before Monday when the garage comes back to me.

Can't help with the measurements,my van is parked up away from home at present. What you describe can't be doing tyre wear a lot of good though, never mind road holding. Good Luck.

Have you checked the Vin no build record to see what suspension you should have?

http://carinfo.kiev.ua/cars/vin/mercedes

Hi Peter, yes it's the correct suspension it is just something they have seriously messed up when they put the new springs on. I am just trying to suss everything before I let them near it again. Deep joy.
As Pete T said a tad disappointing standard of work from a Mercedes main dealer 

Hi Pete


Wheel base front to rear wheel centres:

L/h (Nearside)  432.5                          R/h (Offside)   434.5

This confirms the axle to spring mount dimensions.

Have found excellent USA Sprinter Forum and Merc Engineer has come back with correct procedure for changing rear springs which includes taking dimensional checks from old spring dowels as well as obtaining matched new springs as alignment dowels will vary from spring manufacturer to manufacturer. Also to verify prop shaft is at 90deg to axle and then carry out basic alignment checks. Mercedes Hull seem to have missed these bits in the maintenance manual

Link to the US forum would be good.

This one ? http://www.benzworld.org/forums/w901-905-sprinter/

Hi Peter,

Think this might work

http://sprinter-source.com/forum/index.php

Well, MH back in the drive. Mercedes Hull very hang dog as it appears theY put one spring on back to front. Hmmm, not totally convinced but it runs straight and level again and I did mention a free service for the hassle 
I was quite ok about it all though as they were quick to sort it all out and as the saying goes 'sh.t happens'. 

Good to know they easily fixed it and no permanent damage done,other than to their reputation perhaps.

Out of interest... could you measure between the wheel-centres again?  
It seems remarkable that it is even possible to put a cart spring on back to front these days.
Glad that you are sorted.

Pete Taylor wrote:Out of interest... could you measure between the wheel-centres again?  
It seems remarkable that it is even possible to put a cart spring on back to front these days.
Glad that you are sorted.

Morning Pete,

Measured at 433 a side so that is now correct and it flies straight and level again.

Loking at my previous measurments of where the axle sat on the springs I can't see how turning the spring 180 which is what the 'said' they did would work. I think they have ground off the locating stud and positioned the axle correctly. This is just my assumption, no proof. Not something that particularly worries me as long as it doesn't move. 

However I now have points to ponder considering your previous paragraph where you mentioned spring types.

While I was under the van at the garage discussing my findings and the previous visit to change the broken spring, they told me that BOTH rear springs were broken. Which was a bit of a shock.

1) Now, why did both springs break on a 15 month old Sprinter which has been cared for like a new born baby and never ever been overloaded.
2) if they have both broken once we must make the mechanical calculation that they will break again?
3) looking at the spec for the vehicle on the vin # web site it states 'heavy duty rear suspension'. Has it actually got heavy duty rear suspension? Northside Merc say they just order from the chassis number but assure me it is heavy duty.
4) Is it heavy duty enough ?
5) I had better keep spare springs in the tool box 

I think I will ask these questions of AS.

John,

Now I am concerned! 

Having a similar weight van (only slightly newer), I have been following your spring "saga" with some interest and reading of your Merc dealers revelation that both had failed is extremely worrying. 

I could accept one spring failing due to bad QA or faulty material but for both to fail is slightly alarming and thus, IMHO, not a random event. 

As with all of us, I am sure you have treated your pride and joy with kid gloves, it follows that this must be some form of design/strength issue or another (I refer to the SAM locking failure) AS/Merc load requirements interface issue. 

All of which adds some "weight" to Pete's findings revealed in his suspension dissertation above - there would appear to be a lot of confusion surrounding the correct spring/suspension requirements for motor-homes.

I would be interested in the results of your discussions with AS; in other words - should we be regularly checking underneath our vans? - do we need to consider fitting some sort of supplementary support?  Are all of our vans on the margins for the Merc supplied suspension?

Perhaps its all the fault of the local councils and their woeful maintenance of our roads!!

Look forward to hearing the response you get from AS and meanwhile I will be having the occasional look underneath just to make sure all is well!!

Liam

What code is "heavy duty rear suspension"?

My Merc has CF6, A50, C45 referring to front suspension, but only C33 & C43 for rear suspension plus XL8 weight increase to 3880kg.

C33 Rear Spring Harder.
C43 Rear axle stabilizer reinforced steel frame.

John,
I am inclined to think that M-B suspension is normally fit for purpose and you have been unlucky in getting two forgings from a bad batch (were both the breakages identical?). A brief inter-web search produces no horror stories about broken Sprinter springs, although the Vito seems to suffer from breakages of coils. So; one has to hope that A-S specification vehicles are man-enough for the payload.

Now... cost of our new van: about £63k
          cost of Drive Rite semi-air suspension: £525 fitted
          cost of peace of mind: priceless.

I know that I did a bit of a deal, due to bad customer service but even £525 does not sound expensive when put against the van.

I've not really driven very far yet- back from Stoke to home was about 30 miles via the "most winding/up and down route" plus another joy-ride and the transformation is already apparent. No more slightly swaying/rolling back end, the Firestone airbags really do seem to improve the ride and handling and I've not played with the pressures at all. The van is now sitting about an inch higher at the rear, so I'm guessing we are thereabouts with 30psi. I've not driven in cross-winds yet, or experienced that sideways shove when passing artics. I have been reading up about the "cross-wind assist" which M-B fit to our new vans and it seems to have to be pretty extreme before anyone can actually feel it working. With the semi-air I'm guessing it will be even less frequently in play.

I went for the simplest kit- no gauges, as I carry a compressor with me to inflate the tyres, this has a gauge. From what folks have told me the pressure should not require adjustment for at least a month, probably much longer and it only takes a minute to kneel down with the pocket pressure-gauge to see if I need to get the compressor out. I don't want ugly after-market clocks stuck on my dash.

Here is the Drive Rite info:  http://www.driveriteair.com/catalog/category/semi-air-suspension-kits

Any opinions folks?

I added the Dunlop system, had the gauge/valves fitted in the existing nearside recess by the hab door. System would not help if spring broke though.

Pete,

Was the Drive Rite system endorsed by both AS and Merc? 

And if so, presumably does not effect your warranty rights?

I agree with your thoughts that the peace of mind element is priceless as is safety. I dread to think what the consequences of a leaf spring failure might be at speed and on a bend! 

I think I might be giving some serious consideration to fitting the fore mentioned system.

In the meantime I would be interested to hear how you rate its performance once you do get out on the road again.

Liam

Leaf spring failure is not as drastic as it sounds. There are bump stops above each end of the axle and the axle only sits about an inch below them anyway. When ours failed I did not even notice one side was a tad lower. It made no difference to handling other than felt like I was on solid rubber tyres. No difference to normal then  . I only noticed something was awry when the broken 'free' end of spring tapped on the chassis when I went over a sleeping policeman. (Woke 'him' up ha ha).

As the leaf springs are anchored each end and a failure would be either in front of or behind the axle everything remains in place. The spring which is still attached to the axle acts like a leading or trailing link. Each end is in a rubber bush which also stops the broken piece dropping into the road.
So quite a safe failure really 

Liam wrote:Pete,

Was the Drive Rite system endorsed by both AS and Merc? 

And if so, presumably does not effect your warranty rights?

I agree with your thoughts that the peace of mind element is priceless as is safety. I dread to think what the consequences of a leaf spring failure might be at speed and on a bend! 

I think I might be giving some serious consideration to fitting the fore mentioned system.

In the meantime I would be interested to hear how you rate its performance once you do get out on the road again.

Liam

Liam,
A-S paid a third of the cost of fitting the air system and Merc, at least in some countries, seem to offer to fit after-market air upgrade kits, so I guess that's OK.

Leaf springs really offer quite limited travel, compared to what we are used to on modern cars, perhaps two inches in compression and something less in the opposite direction; see John's comment. The semi-air units replace the solid rubber bump-stops and assist the leaves, reducing the load on them, making over-loading of the leaves less likely.
Even if a leaf breaks at the other side of the axle to John's situation, the remaining part of the spring would act as a link. I used to have a couple of sports cars which had semi-elliptic leaf springs, which is, in effect, what you finish up with if your Merc spring breaks.

What would be an absolute * Inappropriate Word * would be if you broke a spring in some remote location; OK the Merc recovery package is full of fine words about getting you back on the road quickly in any situation but I think it is best not to test that scenario!

 Perhaps we need a separate thread about folks' experiences with semi-air suspension?

Pete Taylor wrote:
Even if a leaf breaks at the other side of the axle to John's situation, the remaining part of the spring would act as a link. I used to have a couple of sports cars which had semi-elliptic leaf springs, which is, in effect, what you finish up with if your Merc spring breaks.

What I should have said (of course!) is the sports cars had quarter elliptic springs- the cart springs we have on the Sprinter are semi-elliptic!

PLOUGHLIN wrote:What code is "heavy duty rear suspension"?

Hi Poughlin, there doesnt seem to be a code for the heavy duty rear suspension. Not long after I bought it I had an issue with the number of gears in the auto box (another story   ) so went direct to MB customer services UK with a few questions and they advised me it has heavy duty rear suspension and axle.

If it has or not is a completely different story of course 

Jaytee wrote:

Pete Taylor wrote:Out of interest... could you measure between the wheel-centres again?  
It seems remarkable that it is even possible to put a cart spring on back to front these days.
Glad that you are sorted.

Morning Pete,

Measured at 433 a side so that is now correct and it flies straight and level again.

Loking at my previous measurments of where the axle sat on the springs I can't see how turning the spring 180 which is what the 'said' they did would work. I think they have ground off the locating stud and positioned the axle correctly. This is just my assumption, no proof. Not something that particularly worries me as long as it doesn't move. 

I would be very concerned if the "ground off the locating stud" The stud has a purpose and it is to stop the axle moving fore and aft on the spring - removing it would be suicidal on any vehicle, never mind a motorhome of 3.5 tonnes!