Merc 609 wheels on a Merc 410D (1 Viewer)

[dflambe]

I have a 1996 410D with 185/75/R14 wheels annd found the engine seemed to be screaming at 50mph. I took the plunge have just put 609 wheels on instead (225/75/R16). I'm now able to comfortably do 55mph now with out the engine sounding like it's going to take off.

Question is!! My van did have twin wheels on the back but I decided to only put singles of the bigger tire on. I have them fitted so that they dish out, that is, I have left the inside wheels off so as to maximise the wheel base width. Do you know if this is a bad idea or will it make any difference? (the van is only 2,700kgs). Would it be advisable to get the tracking/toe in re-aligned after changing to the 609 wheels?

Dave

 

[JJ]

I am no longer a motor mechanic so I don't know for sure but I would never run a twin wheeled axle with only one wheel each side unless getting to a garage (slowly) after a puncture and my spare was flat.

JJ

 

[knokinonabit]

The wheel dish is designed to run a certain way round and putting it on "back to front" would be a no no in my humble opinion. The holes for the wheel nuts are shaped to fit flush to the hub and usually dished so that the wheel nut fits in it to align the wheel properly, and give the wheel nuts "grip".
If it had twin wheels then that is what the axle was designed to take.
It may be possible to buy a conversion, but probably not.

Personally I would not run them as singles as the dishes are the wrong way round from how they were designed to be used and could put undue stress on them. It may not even be legal, at a guess.

I'm sure someone who knows better will advise you, but I would not take the risk until I knew for certain. Ask a Merc dealer and see what they say.

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[TheBig1]

have you changed the speedometer gearing to take account of the larger wheels? If not, the speedo will be significantly out and reading under speed. You need to know the true speed to avoid speeding tickets

each revolution of the larger wheels/tyres will take you further, reducing the gearing, so reducing engine effort/noise. As for running a twin wheel axle on singles, this is potentially dangerous and breaches the vehicle type approval. you are placing double the load on each tyre and placing increased cornering and braking forces on the hub/wheel

As JJ said, only ever do this in an emergency and for short didstance and low speed. If you were to be stopped by VOSA, they would put a prohibition notice on the vehicle and hand you a decent sized fine too

 

[aba]

if you have changed the wheel size from manufacturers spec you had better get the speedo re-calibrated as it will now be lying.
i am also surprised that a Merc 4.10 weighs in at only 2.7 ton
as for the rear wheel issue i would be surprised if you can get away with running a single on a dual axle legally.

also if i was your insurance company and you had an incident with this vehicle i would be looking at this as a reason for not paying out on your claim.

 

[dflambe]

Hi folks
Thanks for all the replies. We have weighbridge where I work and that's the weight alright! Had a few people (well everybody) saying about the legality in the event of an accident.
I take on board what you are all saying and I'll get doubles on the rear axel. Would probably get away with driving in Ireland as it is, but if I go into Northern Ireland, UK or Europe UK I'd be stuffed.

The missus is getting peeved at this stage, I just keep spending money like it's going outy of fashion!!

Thanks to ye all.

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[JJ]

Good man... you know it makes sense... also with four driving wheels at the back you get better stability and more grip in damp conditions...

... but keep off continental toll roads... with twin wheels on the back they count you as a big truck :Angry:

JJ :Cool:

 

[dflambe]

Can't fit the second wheel on!!!!!oh: It's rubbiing off the leaf spring. Some body mentioned doing something with the springs, any ideas?

Might try a smaller tire have 225/75/R16 Load Index 118 on at the moment.

 

[TheBig1]

i think changing the tyre width will be the only way. theres no way a set of spacers will take the strain of twin wheels.

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[dflambe]

Hi Thebig1,
Can't use spacers because of the hub centric. Spacers would leave the wheels sitting on the studs only. That wouldn't be good. Going to have to find a nice friendly garage who will try different size tyres on for me!!

Can anything be done with the springs?

Dave

 

[TheBig1]

Hi Thebig1,
Can't use spacers because of the hub centric. Spacers would leave the wheels sitting on the studs only. That wouldn't be good. Going to have to find a nice friendly garage who will try different size tyres on for me!!

Can anything be done with the springs?

Dave

I cant think of anything you could safely do with the springs. even fitting airbags in place of the bumpstops wont work, as it wont change how far into the wheelarch the tyres go. the tyre width is the only way to change this, (or fit different wheels,) as narrower tyres take up less space. your 225/75/16 tyres are 225mm wide without a load, so 205 tyres are 205mm wide etc

 

[dflambe]

Hi TheBig1,
Found a post on Motorhomefacts.com from a guy who put the bigger tyres on and shaved the leaf springs to allow for the tyre bulge!

Is this doable? or dangerous? If you're not carrying huge weight may be okay? no?

Do you know anyone who could advise?


Dave.

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[veevee]

Dave, what is the wheel rim width? It should be stamped on the rim somewhere.

 

[dflambe]

Can't look at it now but I'mm 99% sure it's 6"? Why?

 

[pappajohn]

with the size you have now fitted (225/75/R16) you will probably get 'tyre kiss' if reverting to the twin wheel set up.

tyre 'kiss' is when the inside walls of the twin tyre setup touch each other where they 'belly' out at the bottom.

this is potentially dangerous as the tyres will overheat due to rubbing together resulting in a blowout of one tyre at least.

you are wading through treacle with this kind of mod.

with a single wheel setup you have altered the axles designed weight limit.
doubtful your insurers would approve the 'alteration'.
putting the wheels on back to front will probably put undue stress on the wheel bearings.
chances are it wont pass an MOT, if the tester is worth his salt
with a twin wheel setup, of the new size, you will overheat the tyres due to tyre kiss.
any alteration to the springs to stop the tyre rubbing will not be possible without major re-engineering and wouldnt get insurance approval.
at an indicated 55mph you will probably be doing a true speed of over 60mph and its illegal to have a speedo indicate too slow.
at vehicle manufacture the speedo is designed, by law, to read fast or be accurate..but never slow.

the only realistic way to overcome the revs/noise problem is to alter the final drive ratio.

assuming you are rear wheel drive it would be easier to change the rear axle for one of a higher ratio and recalibrate the speedo to suit.
front wheel drive would possibly need a different gearbox from a model designed for a different working environment.

personally, i would leave it as it was and spend the money on better, more efficient, sound deadening materials

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[TheBig1]

shaving down springs is very dangerous, as it seriously weakens the spring leading to a likely failure with the spring failing at the weak point. I dont know of any engineer who would do this, if they did, the springs would need to be re-engineered and heat treated.

i know it used to be a fairly common practice with some custom car builders, but these were lighter vehicles obviously. you certainly cant just take an angle grinder to the springs and shave a bulge out

As Papajohn has already pointed out, there is a lot more to changing the wheel setup especially with twin wheels, than it appears initially. I dont want to be alarmist, but i am sure you wouldnt want a wheel shearing off, a tyre blowout or suspension collapse when driving at speed on a motorway. not good to think about, but get this wheel change wrong and thats a "possible" outcome

 

[dflambe]

Hi Lads,
I hear what you are all saying about safety and stuff like that, and I can assure you that I'm not the type to disregard all your advice and am certainly not going to endanger myself or loved ones for the sake of a few liters of diesel and and extra 10mph.

I'm just exploring the possibilities. I still have my original 14" wheels in the garage if I need them.

Dave.

 

[pappajohn]

while i cant open the link you placed (this forum doesn't allow links to certain websites and thats a 'fact' ) i have read the relevant thread/posts on the other forum, and in my opinion Merctoby is mad putting an angle grinder to the side of the leaf springs and then leaving just a millimetre or two clearance. oh:
a little distortion in the tyre and it will rub on the spring.

all he's done, in my opinion, is introduce a weak spot in the leaf spring even though he says the springs are over engineered for the weight

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[dflambe]

I was thinking 2mm was a bit small myself. Sure the tyre would flex that much if you hit a bump or a speed ramp.

He may have a point about german over engineering but that's just it I need to speak to an engineer!!

I think I'm going to go to a tyre fitting place and ask them to try difference size tyres on. I know the 225 is too wide so I'll work down from that.

 

[veevee]

Dave, I think your tyres are far too wide and I think you have written that too.

The rim size will have a minimum and maximum tyre size allowed, a good tyre shop can tell you that.

It is also possible to contact a Mercedes dealership and ask what is the correct tyre size for a 609D, that's probably the easiest route to find the tyre size that works correctly for those rims, MB will have got that right.

I heard from someone who used 609D wheels and tyres on a 410D D based Hymer motorhome for many years, he said they just bolted straight on without any mods at all... but he had the correct tyres fitted.

On Monday or Tuesday I will be at the tyre shop I have used for 30 years, there are a couple of very experienced trye fitters there and I was going to ask them to give me the correct size for the 609D and also the minimum and maximums for the rim. But if you contact MB first it may get you the answer faster.

Most vehicle modifications have knock on effects on other components. A small percentage of mechanical changes improve the vehicle, the vast majority don't. Most changes make a vehicle less safe.
If it were only you in the vehicle then it's your choice as to what you do, but it appears your family will be with you...

So as everyone else here writes, don't alter a safety item unless it is well proven under testing conditions.

Just my three penny worth

 

[dflambe]

The end of the story

Well folks,
The wheel saga is over. The van is now back on twins with the correct Load index and six brand new 185/75/R16 tyres. Drives like a new van!

I don't understand how people said they fitted 215 or 205 tyres. I tried 195's and even they were a bit close for comfort to the springs.

So if anyone ever asks about fitting 16" wheels on a merc 410 the answer is yes, but you can only fit 185 tyres. I gained an extra 10kmph roadspeed. 50 is now 60, 60 is now 70, 70 is now 80 and so on.

Was it worth it? Yes! Travelling in the van without the roaring engine noise has made for a much more relaxing and enjoyable journey, not to mention less fuel usage. I'm not going any faster just quieter.

Only downside is I can hear her giving out to me now!!

Thanks to you all for your patience and welcome advice.

Dave.

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[aba]

your next problem will be big hills as you will lose so much speed going up you may have to use first gear

 

[dflambe]

I actually feel it is better on hillls and such. Maybe its because I have more speed and momentum?

 

[Dookarah]

Hi there Dave.We envy your new wheels. sounds like a good plan. Now we wonder if you still have the old ones as we are in sore need of a spare and have had no joy at all locating one for less than the top dollar for a brand new one from the merc garage. We would be grateful if you could sell a wheel,
many thanks,

Jen :thumb:

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[dflambe]

Hi Dookarah,
Give me a call 0870652820

Dave

 

[Dookarah]

Will do. Cheers