Suspension 16.49 ATM Upgrade

[Optima]

Hi All,
I am currently looking in to upgrading my expanda's ATM to 2300 kg as with solar and water etc I sit around 2100 kg loaded for a trip which is way over my current ATM of 1830kg.
My question is has any upgraded there springs to the 2500 kg 10 leaf Al-Ko, my concern is they may be to stiff and cause a harsher ride than I now have..
My other question is can anyone offer up the best size tyre and rim upgrade, Iam thinking 245/70/16" ? I am wanting to obviously increase load capacity while trying to increase ride height.
Thanks in advance.
Cheers.

 

[AdrianVVV]

Hi Optima,
I'm currently going through the same process for my 14.44 which has existing ATM of 1930, I'm looking for a similar increase to you. I am now at the engineering stage and still have a few things to work out. Based on my experience I doubt you can just change the springs (sorry) you will also need to look at axle, coupling, rims/tyres ratings and possibly chassis/drawbar. You will also need a breakaway brake system when ATM over 2000kg. I found all components were reasonably closely rated to the original GTM/ATM, except tyres which were 105 (925kg), very close to the limit (thanks Jayco).

Another approach might be to look at increasing the towball loading so van GTM (ATM - ball weight) is under 2000kg and might avoid changing springs etc. You will need to consider if your vehicle will support this (and allow for the reduced vehicle payload). For example if you have a towball mass of 300kg, the ATM could be 2300kg with the van itself (GTM) only 2000kg. I hope that makes sense, I've been doing a lot of research on this lately.

Depending on the state you will have different requirements/approval to keep it legal, insured etc. in Vic we need an engineering certificate for any changes to the compliance plate details.

Regarding tyres/wheels, there are a tonne of options... Be careful to take the rim offset into account as well as capacity otherwise your new wheels might not fit. Common tyre sizes in 16" appear to be 245/70R16 and 225/75R16. If your diameter increase is too much it might downrate your brakes, but assuming you have the 12"*Try posting a bit more so your post isn't boring*" Al-ko should be ok. Apparently 265/70R16 used to be a factory option but these could rub the guards (depending on how accurate the guard placement was) and are no longer offered.

This article has a good introduction into the things to be considered:
http://www.candm.com.au/atm/

There are several threads on this site and others dealing with similar experiences. For example:
https://www.expandasdownunder.com/threads/had-a-mod-plate-done-today.8200/
https://www.expandasdownunder.com/threads/upgrading-atm-on-our-17-55-5sh-ob.9617/
http://caravanersforum.com/viewtopic.php?t=70598

Look forward to hearing your progress, when I get it done I'll post my experiences.

Adrian.

 

[Drover]

I run 245 70x16's on Big Mal and I can tell you they are flamin big and are heavy so will eat up some of your gain, you will have to do some careful measurements to see if they will fit, allowing for spring compression movement...........as stated you would require new axle, springs, hangars, rims and possibly hubs if only 10", since it legally requires engineering your increase in height would be governed by the height of your tow hitch so if you wanted more then it may have to be repositioned.

I replaced the springs and stuff on my 14.44 along with rims but only because the springs were rubbish and the original rims and tyres were under rated.......

Some states you can upgrade the GTM but not the ATM

 

[Optima]

Hi Optima,
I'm currently going through the same process for my 14.44 which has existing ATM of 1930, I'm looking for a similar increase to you. I am now at the engineering stage and still have a few things to work out. Based on my experience I doubt you can just change the springs (sorry) you will also need to look at axle, coupling, rims/tyres ratings and possibly chassis/drawbar. You will also need a breakaway brake system when ATM over 2000kg. I found all components were reasonably closely rated to the original GTM/ATM, except tyres which were 105 (925kg), very close to the limit (thanks Jayco).

Another approach might be to look at increasing the towball loading so van GTM (ATM - ball weight) is under 2000kg and might avoid changing springs etc. You will need to consider if your vehicle will support this (and allow for the reduced vehicle payload). For example if you have a towball mass of 300kg, the ATM could be 2300kg with the van itself (GTM) only 2000kg. I hope that makes sense, I've been doing a lot of research on this lately.

Depending on the state you will have different requirements/approval to keep it legal, insured etc. in Vic we need an engineering certificate for any changes to the compliance plate details.

Regarding tyres/wheels, there are a tonne of options... Be careful to take the rim offset into account as well as capacity otherwise your new wheels might not fit. Common tyre sizes in 16" appear to be 245/70R16 and 225/75R16. If your diameter increase is too much it might downrate your brakes, but assuming you have the 12"*Try posting a bit more so your post isn't boring*" Al-ko should be ok. Apparently 265/70R16 used to be a factory option but these could rub the guards (depending on how accurate the guard placement was) and are no longer offered.

This article has a good introduction into the things to be considered:
http://www.candm.com.au/atm/

There are several threads on this site and others dealing with similar experiences. For example:
https://www.expandasdownunder.com/threads/had-a-mod-plate-done-today.8200/
https://www.expandasdownunder.com/threads/upgrading-atm-on-our-17-55-5sh-ob.9617/
http://caravanersforum.com/viewtopic.php?t=70598

Look forward to hearing your progress, when I get it done I'll post my experiences.

Adrian.

Hi Adrian,
Thanks for the very detailed reply.
I have a lifted 200 series cruiser & my expanda is an outback with 12" brakes and 6" chassis, running a 3t Mchitch already.. sorry I should have added this.
I have been to an engineer and had many phone calls to Al-Ko re my bearings and axle group loading etc axle has a 2T SWL and the bearings are rated at 2250 kg - All good to go 2000 kg GTM and 2300 kg ATM.
My current rims and tyres are not up to the job so this is the area of my main focus, I don't want to spend $1500 and they scrub .
We want to do more beach trips so I am chasing as high of a rated tyre as possible so I can safely air down to 18/22 psi as well as trying to gain some overall diameter for more clearance without under slinging the axle.

My current Al-Ko Outback rebound springs are tired and need replacing anyway but they are rated to a maximum constant load of 2 t and I think sitting at 2 t constantly going up another leaf to 2.5t may give it a bit more in stead of being on the limit, I am just concerned they may be too stiff.

I will let you know how it all goes.
Cheers

 

[Optima]

I run 245 70x16's on Big Mal and I can tell you they are flamin big and are heavy so will eat up some of your gain, you will have to do some careful measurements to see if they will fit, allowing for spring compression movement...........as stated you would require new axle, springs, hangars, rims and possibly hubs if only 10", since it legally requires engineering your increase in height would be governed by the height of your tow hitch so if you wanted more then it may have to be repositioned.

I replaced the springs and stuff on my 14.44 along with rims but only because the springs were rubbish and the original rims and tyres were under rated.......

Some states you can upgrade the GTM but not the ATM

Thanks for the reply Drover,
Do you think a 245/75/16 would fit or I am pushing the limit and should stick to a 70, Al-Ko advised the the rebound springs only have a maximum deflection of 60 mm in both directions.
A 75 has considerable more load capacity than a 70 from what I researched giving me more comfort in being able to air down on the beach and corrugations.

Cheers.

 

[AdrianVVV]

Hi Optima,

Sounds like you are on top of it all, and we are at a similar point in our efforts. I thought that might be the case after I had already pressed send... hopefully someone finds it useful.

Where did you get the actual ratings for the bearings? The Al-ko catalogue lists them variously as 2T and 2/2.5T and also uses the same inner bearing (HR30210) in the Al-ko 3 tonne set and Dexter uses the outer (15123) in their 2.5 tonne bearing set. My plan is to re-use the existing bearing sets on a new larger axle machined to that profile, ideally to a capacity of around 2300kg. If I can use these bearings it would save having to also replace the brakes. This is also one of the questions I had for the engineer.

For tyres I have plenty of height (tyre diameter) available in my van (including allowance for compressing 50% of the end stops) and the 245/75's would be fine for me. Width is my problem as ideally I would like to run 265/70 R16's to match the car (although rims are not completely interchangeable). I measured the distance between the inner guard to the outside guard at 290mm on one side and around 300mm on the other. This would leave me with 25mm clearance to the inner guard and running to the outside guard. I think this is too tight but am happy to hear others thoughts. I have the extended drawbar and the 265 fits in the spare location with no problems, as would the 245/75.

Drover's note on the additional weight all this new gear also a concern, my ATM increase needs to be substantial to actually achieve payload gain after the new (heavier) suspension/wheels are added.

Your question re springs, your van is only GTM of 2000kg, so I would be concerned using stiffer springs (2500kg). I'm torn on what to do with mine, if I make the van GTM 2200kg I am right in between spring sizes.

Adrian.

 

[Optima]

Morning Adrian,
Al-Ko advised verbally of the bearing capacity and my Engineer also advised the same, sorry no actual written confirmation.
I was unable to find an axle rated at 2.5t to suit my hubs, so a complete swap out was evident and the cost just becoming over the top. After speaking with Al-ko the weight gain for the setup was also extreme and would negate any GTM gain so I have come to the conclusion that I will just upgrade to the 2000/2300 and work with that.

245/75/16 seems the best option for an all round gain, unfortunately my cruiser runs 18's so I am unable to even get a close match.

Thanks again for the reply.
Good luck with your upgrade!!
Cheers.

 

[Drover]

Oooppss, I had a finger error tyres on my van are 265 70 16, the 245's are on my ute, when I was doing wheel/spring changes on other van I actually had a test wheel so i could try it out for size.................................
I think talking to a certifying engineer first may save some time as to what changes you may or may not be able to do, some states have changed their regs for compliance plate modifications.......
Going over 2 ton you most certainly would need parrellel bearings where the inner and outer are the same. For springs, axles, hubs and gear theres a good supplyer in Brissie, just can't think of their name but they specialize in trailers and good Jap bearings, a wider range of gear than an Alko Catalogue ,very good to deal with.

 

[dosmos]

Last year I upgraded the ATM on my 2014 Jayco Starcraft OB - didn't do any changes - took the van to Archie Robertson :
https://www.yellowpages.com.au/vic/...on-auto-marine-services-12543771-listing.html
Certified VAAS Engineer in Bayswater VIC. Previous ATM was around 2720 - upgraded to 3000. Took the new compliance plate & certificate to VicRoads and Rego Cert was changed. FYI DOS

 

[Optima]

Oooppss, I had a finger error tyres on my van are 265 70 16, the 245's are on my ute, when I was doing wheel/spring changes on other van I actually had a test wheel so i could try it out for size.................................
I think talking to a certifying engineer first may save some time as to what changes you may or may not be able to do, some states have changed their regs for compliance plate modifications.......
Going over 2 ton you most certainly would need parrellel bearings where the inner and outer are the same. For springs, axles, hubs and gear theres a good supplyer in Brissie, just can't think of their name but they specialize in trailers and good Jap bearings, a wider range of gear than an Alko Catalogue ,very good to deal with.

Thanks for the reply drover, I will check prior to purchase, 265's are definitely my preference.
Cheers.

 

[Dozer54]

Hi Optima,
I'm currently going through the same process for my 14.44 which has existing ATM of 1930, I'm looking for a similar increase to you. I am now at the engineering stage and still have a few things to work out. Based on my experience I doubt you can just change the springs (sorry) you will also need to look at axle, coupling, rims/tyres ratings and possibly chassis/drawbar. You will also need a breakaway brake system when ATM over 2000kg. I found all components were reasonably closely rated to the original GTM/ATM, except tyres which were 105 (925kg), very close to the limit (thanks Jayco).

Another approach might be to look at increasing the towball loading so van GTM (ATM - ball weight) is under 2000kg and might avoid changing springs etc. You will need to consider if your vehicle will support this (and allow for the reduced vehicle payload). For example if you have a towball mass of 300kg, the ATM could be 2300kg with the van itself (GTM) only 2000kg. I hope that makes sense, I've been doing a lot of research on this lately.

Depending on the state you will have different requirements/approval to keep it legal, insured etc. in Vic we need an engineering certificate for any changes to the compliance plate details.

Regarding tyres/wheels, there are a tonne of options... Be careful to take the rim offset into account as well as capacity otherwise your new wheels might not fit. Common tyre sizes in 16" appear to be 245/70R16 and 225/75R16. If your diameter increase is too much it might downrate your brakes, but assuming you have the 12"*Try posting a bit more so your post isn't boring*" Al-ko should be ok. Apparently 265/70R16 used to be a factory option but these could rub the guards (depending on how accurate the guard placement was) and are no longer offered.

This article has a good introduction into the things to be considered:
http://www.candm.com.au/atm/

There are several threads on this site and others dealing with similar experiences. For example:
https://www.expandasdownunder.com/threads/had-a-mod-plate-done-today.8200/
https://www.expandasdownunder.com/threads/upgrading-atm-on-our-17-55-5sh-ob.9617/
http://caravanersforum.com/viewtopic.php?t=70598

Look forward to hearing your progress, when I get it done I'll post my experiences.

Adrian.

See this info
http://www.withoutahitch.com.au/caravan/legal-requirements-caravan-breakaway-systems-australia/
2000 kg requirement for Break Away Brakes is on GTM not ATM

 

[AdrianVVV]

Hi @Dozer54,
Thanks for the correction, you are right. I just looked up the design rules just to be sure (ADR 38/02 clause 5.4). In my case my upgrade brought both ATM and GTM over 2000kg so I guess I didn't pay that much attention to those specifics.