GVM Uprating

[Chris CM]

I am going to uprate the GVM my Devon Aztec XL from 3500kg. I have contacted SV Tech who have offered me two options, upgrade to 3900kg with no modifications or 4500kg with the addition of Air Assistance on the rear axle and, if I upgrade the tyres to 118 rating from 116 I can go to 2600kg on the rear axle, staying with the current tyres it’s 2500kg. My inclination is to go to 4500kg on the original tyres as the only additional cost is the air suspension unit which is a nice thing to have anyway as lots of funsters have reported and I get an extra tonne!

SV Tech offer the VB air assist system with two manometers and manual inflation for £396, which seems quite good?

So, what do you guys think? Has anyone fitted the VB system? Is it a diy job?

chris

 

[ManTheVan]

That seems ok price-wise. I fitted Easytop which, i think, was about £340 delivered from Italy. It’s not a long job and has been transformational on handling and comfort so far. Doing my research, they all seem to be pretty much the same idea. I went for Easytop because the fitting appeared to be less involved as there are no extra brackets to fit; the bellows and fixings are all in one.

One point to note is that with a maximum revendue weight of 4500kg and a limit of 2600 on the rear axle, it might be difficult to achieve your theoretical payload because it’s less likely that you’ll be able to shift the balance of the load over the front axles to use the remaining 1900kg when the rears are at their maximum? Just a thought...

 

[tacr2man]

You need to consider axle loads as well as the GVM as if you stay with 2500 kg rear axle that means your front axle needs to be 2000kg minimum .

 

[Chris CM]

Thanks for your thoughts, yes appreciate that there may be a load balancing issue but I don’t suppose I’ll get anywhere near the max vehicle weight, the only really heavy stuff will be the booze on the way home and that can be centred in the vehicle. The front axle limit is 2100kg so there is a bit to play with, useful as SWMBO and I aren’t lightweights

 

[Chris CM]

That seems ok price-wise. I fitted Easytop which, i think, was about £340 delivered from Italy. It’s not a long job and has been transformational on handling and comfort so far. Doing my research, they all seem to be pretty much the same idea. I went for Easytop because the fitting appeared to be less involved as there are no extra brackets to fit; the bellows and fixings are all in one.

I’ve looked at the Easytop, now on special offer, circa £325 delivered, and I like the idea of not unbolting the spring hanger nuts. Can I ask a question about fitting? In order to get the bellows between the top of the spring and the bump stop mounting was it necessary to raise the bodywork in order to get the bellows in? I have no access to a ramp or lift so I would be working on the ground with only basic lifting gear, is it possible?

Thanks,
Chris

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[Manic]

I’ve looked at the Easytop, now on special offer, circa £325 delivered, and I like the idea of not unbolting the spring hanger nuts. Can I ask a question about fitting? In order to get the bellows between the top of the spring and the bump stop mounting was it necessary to raise the bodywork in order to get the bellows in? I have no access to a ramp or lift so I would be working on the ground with only basic lifting gear, is it possible?

Thanks,
Chris

I also liked the way the bellow clamp to the springs, when I fitted mine I just used the supplied Fiat jack to take the weight off the spring.

 

[125BEER]

Easytop for me and local garage fitted for £130.
As regards to payload you require weigh everything you put in the van Swmbo has a detailed list ......even beer I take

 

[cmcardle75]

I'd be tempted to go for the rear axle upgrade. Only a couple of hundred quid and you get new tyres into the bargain!

Getting some weighbridge figures for your individual axles as they are now would be useful for making decisions. I guess the upgrade itself will also add additional load to the rear.

 

[Chris CM]

I also liked the way the bellow clamp to the springs, when I fitted mine I just used the supplied Fiat jack to take the weight off the spring.

I was thinking along those lines, when I used the jack to let me unbolt the wheel to put some wheel centres on after I dispensed with the wheel trims I found the supplied jack barely lifted the wheel off the ground on full extension so shouldn’t be too unsafe but I had hoped to run her up on the levelling blocks to give me a few extra inches but I suppose I can squirm underneath to put the bellows in then onto the blocks to run the airlines

I'd be tempted to go for the rear axle upgrade. Only a couple of hundred quid and you get new tyres into the bargain!

Getting some weighbridge figures for your individual axles as they are now would be useful for making decisions. I guess the upgrade itself will also add additional load to the rear.

the tyres would be the thick end of £600 for the tyres in addition to the semi air suspension units, so looks expensive for the gain compared with keeping the existing tyres. When the time comes for a tyre change due to wear then I’ll fit the 118 rated tyres. My current tyres are 215/75 R16 the 118 tyres are 225/75 R16, does anyone know if they will fit or am I likely to need new wheels as well?

My rear axle is currently plated at 2400kg so I’m gaining 100kg there withoutout changing the tyres.

Chris

 

[cmcardle75]

I was thinking along those lines, when I used the jack to let me unbolt the wheel to put some wheel centres on after I dispensed with the wheel trims I found the supplied jack barely lifted the wheel off the ground on full extension so shouldn’t be too unsafe but I had hoped to run her up on the levelling blocks to give me a few extra inches but I suppose I can squirm underneath to put the bellows in then onto the blocks to run the airlines




the tyres would be the thick end of £600 for the tyres in addition to the semi air suspension units, so looks expensive for the gain compared with keeping the existing tyres. When the time comes for a tyre change due to wear then I’ll fit the 118 rated tyres. My current tyres are 215/75 R16 the 118 tyres are 225/75 R16, does anyone know if they will fit or am I likely to need new wheels as well?

My rear axle is currently plated at 2400kg so I’m gaining 100kg there withoutout changing the tyres.

Chris

I doubt there will be any problem physically putting 225/75R16 on rims designed for 215/75 R16. However, the wheel itself will have a strength rating that needs to be high enough. I don't know how you'd be spending £600 on tyres for a single axle, or are you changing the fronts too, to keep them the same? I notice that this size does seem a bit more expensive for some reason. Presumably not a common enough size for OEM. Most vans would have moved to DRW by this weight, which would need a slightly lower load rating.

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[tacr2man]

Rim will take the 225 , have you checked for clearance as tyre is wider and taller

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[Chris CM]

I doubt there will be any problem physically putting 225/75R16 on rims designed for 215/75 R16. However, the wheel itself will have a strength rating that needs to be high enough. I don't know how you'd be spending £600 on tyres for a single axle, or are you changing the fronts too, to keep them the same? I notice that this size does seem a bit more expensive for some reason. Presumably not a common enough size for OEM. Most vans would have moved to DRW by this weight, which would need a slightly lower load rating.

Yes, new tyres on both axles, and I forgot the spare! Re the DRW, yes I was surprised that I could go to 4500kg, I was only expecting 3850kg so both options came as a pleasant surprise!

 

[Chris CM]

Rim will take the 225 , have you checked for clearance as tyre is wider and taller

Tire Size Comparison

Tire size comparison the easy way. Use our tire size comparison calculator to compare diameter, width, sidewall, circumference and revolutions per mile.

tiresize.com

Thanks. That’s interesting, I assumed that since they were both R16 that they would be the same diameter, obviously wider. I’ll check the handbook and see if the 225/75R16 is a listed tyre for the van. Luckily, if they do fit then the speedo error is minimal.

 

[tacr2man]

The bead is the same diameter 16" but the tread area as you say is larger diameter

 

[cmcardle75]

The way tyres work is that that the tyre depth is a proportion of the tyre width. This ratio is called the profile. This means that if the width increases, do does its depth (i.e. diameter). The bead size stays the same. You can reduce the profile to keep the overall diameter the same. At least you could if such a reduced profile is available. However, they haven't bothered making such tyres in your case as the difference is so marginal.

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[ManTheVan]

I’ve looked at the Easytop, now on special offer, circa £325 delivered, and I like the idea of not unbolting the spring hanger nuts. Can I ask a question about fitting? In order to get the bellows between the top of the spring and the bump stop mounting was it necessary to raise the bodywork in order to get the bellows in? I have no access to a ramp or lift so I would be working on the ground with only basic lifting gear, is it possible?

Thanks,
Chris

Sure! I used the Fiat scissors jack as my trolley jack did not have the height to achieve sufficient lift. I then took off the wheel and worked from beside the hub, never under the vehicle. I had axle stands but also used the trolley jack as secondary support/failsafe, as the axle stands were at their limit of reach.

A strap wrench was really helpful in removing the bump stops, as they were stiff despite liberal use of releasing fluid. Toolstation (Or it might have been Screwfix!) sells a Silverline double-set quite cheaply (£8-ish?).

Some people here have used another jack between the leaf springs to open them a bit, but if you compress the bellows and use a large plastic zip tie to hold it compressed, it goes in very easily indeed.

Good luck with the job. I found it enjoyable and with a very satisfying end-result.

It’s vital to ensure that the bottom hex bolts are torqued to the recommended setting. It was interesting finding a hex-to-torque-wrench combination that worked, but got there with some creativity.

 

[Chris CM]

Sure! I used the Fiat scissors jack as my trolley jack did not have the height to achieve sufficient lift. I then took off the wheel and worked from beside the hub, never under the vehicle. I had axle stands but also used the trolley jack as secondary support/failsafe, as the axle stands were at their limit of reach.

A strap wrench was really helpful in removing the bump stops, as they were stiff despite liberal use of releasing fluid. Toolstation (Or it might have been Screwfix!) sells a Silverline double-set quite cheaply (£8-ish?).

Some people here have used another jack between the leaf springs to open them a bit, but if you compress the bellows and use a large plastic zip tie to hold it compressed, it goes in very easily indeed.

Good luck with the job. I found it enjoyable and with a very satisfying end-result.

It’s vital to ensure that the bottom hex bolts are torqued to the recommended setting. It was interesting finding a hex-to-torque-wrench combination that worked, but got there with some creativity.

Thanks for your comprehensive reply, luckily I have the tools but my only problem is the lift, my Fiat scissors jack barely lifts the wheel clear of the ground, but I suppose I could put it on a couple of planks to get an extra inch or so. You mention the bottom hex bolts, are these the ones on the bellows clamp? The Italian videos I’ve seen of the install suggest that these are on the inside face of the bellows clamp, was access here a problem from the wheel side?

Thanks,

Chris

 

[Headrush]

Sorry to jump in on your thread. I'm trying to fit the easytop bellows right now. First problem is that although I got the bump stop to unscrew it has now stopped. It turns but it's not undoing anymore. Any suggestions on how to proceed?

It's actually really loose but without destroying the rubber I can't get at the bolt any more.

Help?

 

[Landy Andy]

Just snap the rubber off. You won’t be refitting them, and I doubt they are expensive any way.

 

[Headrush]

OK, thanks. It's a bit final but I'll have to I guess. Hope there's no more show stoppers before I get the bellows in

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[Headrush]

Ha!
Got the rubber off, it's not got a hex head on the bolt! Completely circular. Have to get the stilsons out...

 

[Landy Andy]

It will be rust on the thread I would think, so a bit of lubricant and working it back and forth should make it come off.

I’m talking about the bump stop

 

[Headrush]

Can't get a tool on it. The metal remains of the bumpstop is still in the way and too loose to work against. I've tried trying to brute force the metal off the bolt but it's damaging parts of the chassis.
Somehow I've got to either cut the metal collar off or cut through the bolt.!?, /%:?!
2 hour job they told me

 

[Minxy]

I'm confused, what is your base vehicle? If its the Maxi Heavy you shouldn't need to do any suspension changes to get the higher rate, however if it's the light Maxi you might.

What are the actual figures on your existing VIN plate?

 

[Headrush]

I'm confused, what is your base vehicle? If its the Maxi Heavy you shouldn't need to do any suspension changes to get the higher rate, however if it's the light Maxi you might.

What are the actual figures on your existing VIN plate?

It's not a maxi. It's a ducato x250 base, autotrail cheyenne 632 body. I've been told by svtech that I can uprate to 3850 with rear air and get the rear axle to 2240 with rear air and 112 rated tyres.
I've not got the tools or the patience to finish this now. All I need is for the van to fall off the stands or something, so I'll let a professional do it.

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[Chris CM]

I'm confused, what is your base vehicle? If its the Maxi Heavy you shouldn't need to do any suspension changes to get the higher rate, however if it's the light Maxi you might.

What are the actual figures on your existing VIN plate?

Base vehicle is a Ducato Maxi, current plated weight is 3500kg, Front Axle 2100kg, Rear 2400Kg, by fitting the Air Suspension, according to SV Tech, the rear Axle goes to 2500kg on the existing 116 tyres and with 118 tyres 2600kg.

 

[Minxy]

It's not a maxi. It's a ducato x250 base, autotrail cheyenne 632 body. I've been told by svtech that I can uprate to 3850 with rear air and get the rear axle to 2240 with rear air and 112 rated tyres.
I've not got the tools or the patience to finish this now. All I need is for the van to fall off the stands or something, so I'll let a professional do it.

Sorry, I was 'asking' the OP.

 

[Minxy]

Base vehicle is a Ducato Maxi, current plated weight is 3500kg, Front Axle 2100kg, Rear 2400Kg, by fitting the Air Suspension, according to SV Tech, the rear Axle goes to 2500kg on the existing 116 tyres and with 118 tyres 2600kg.

I don't really understand this, if those as your weights it's already on the heavy Maxi chassis so you should just need to change the tyres to go up to 4500kg with no need to do the suspension at all - most tend to come with the 118 tyres but I am aware that some have the lower rated ones (possibly a cost option?). I, and others on this forum, have done this uprate without any issues as we were fortunate to have the 118 tyres already.

Unless you really want the suspension it might be worth just doing the tyres and upping to 4500kg and sticking with the existing 2400kg rear axle limit as you are not likely to get anywhere near topping it, we never did. Don't forget you can sell your existing tyres to get some of your dosh back so it might not cost you much anyway.

Did you ask them about just doing tyres and uprating?

 

[Chris CM]

I don't really understand this, if those as your weights it's already on the heavy Maxi chassis so you should just need to change the tyres to go up to 4500kg with no need to do the suspension at all - most tend to come with the 118 tyres but I am aware that some have the lower rated ones (possibly a cost option?). I, and others on this forum, have done this uprate without any issues as we were fortunate to have the 118 tyres already.

Unless you really want the suspension it might be worth just doing the tyres and upping to 4500kg and sticking with the existing 2400kg rear axle limit as you are not likely to get anywhere near topping it, we never did. Don't forget you can sell your existing tyres to get some of your dosh back so it might not cost you much anyway.

Did you ask them about just doing tyres and uprating?

Looking at the existing max weights on the plate perhaps there is no need to uprate anything? The possible max weight is already 4500kg, as the tyres are rated at 1250kg then perhaps it should just be a paper exercise? In their quote to me they stated “...I am pleased to confirm that we can uprate your vehicle and have carried out full dynamic brake test results on a precedent vehicle to achieve a GVW of 3900 or 4500kg for category M1 and N2.” And they go on to say that to achieve 4500kg I would need to fit supplementary air assist to the rear.
How did you go about your uprating, did you use SV Tech or some other company? Though to be honest I rather like the idea of the air assist on the rear suspension and it’s not too expensive if I can fit it myself.

 

[125BEER]

It's not a maxi. It's a ducato x250 base, autotrail cheyenne 632 body. I've been told by svtech that I can uprate to 3850 with rear air and get the rear axle to 2240 with rear air and 112 rated tyres.
I've not got the tools or the patience to finish this now. All I need is for the van to fall off the stands or something, so I'll let a professional do it.

Find a local garage I did for £130 couldn't do it myself secure storage on slight slope.all the best.

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