Chassis Upgrading ATM on our 17.55-5SH OB.

Herbertclan

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Mar 6, 2016
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For those who are interested.

I have been replying to a post in another section of this site re getting info to upgrade our ATM and felt I needed to start a separate thread. The below info is what I have gathered and emphasise it is up to the individual to be comfortable with what they are committing to.

Honourable mention to @Glen Bundesen as he is pretty close to the mark on his comments in the other thread.

I'm currently trying to have my Tare corrected to reflect the correct weight due to additional things added after being built and compliance by Jayco along with an ATM increase. I'm unsure of what was done by the dealer and by the previous owners but I'm already guilty of adding to this and want to have the Tare corrected to suit. I want the tare corrected from 1797kg up to the new tare which is approximately 1900kg. The ATM I hope can be raised from the plated 2272kg upto 2500kg (maximum for our Prado).

After getting the rejection from Jayco in getting a compliance plate mod done I went to task calling caravan repair and modification places in Perth, most either said they can't do it or that it can't be done. I also spoke to dot who also said raising the ATM can't be done.

I spoke to a nice chap today that has pointed me in an alternate direction, it doesn't appear to be a widely known thing but I was told today that I can add a secondary compliance plate with revised weights that has myself or someone as the manufacturer. In short this is used when you upgrade a trailer with bigger suspension and or brakes to increase your ATM from what the original manufacturer built and compliance it as. This process is critically based on the following being up to the task of the requested increase in load rating and being prepared to sign off that the chassis is up to the increase in ATM.

The below details are what I need to complete the form, I then need to sign and present to the examiner (or this is how I have taken the info given), the examiner will need to inspect the van and I need to have the relevant info confirming the suspension and axle group is what I say it is.

1) hitch is rated for the increase ( mine is 3.5t, ex factory)

2) Springs are rated (mine is ALKO 6 leaf tandem axle ex factory, Jayco compliance plate has it as "axle group load capacity" of 2700kg ) martins trailer parts confirmed it is likely 3000kg rated being six leaf springs.

3) brakes are rated and include the part number. ( mine are 254mm x 54mm ALKO electric drums "off road" ex factory)

4) it is fitted with breakaway brakes. ( our is fitted ex factory )

5) tyres are rated. ( 235/75R15 AT Savero GT Radials 105T ) rates to 3700kg collectively.

6) rims are rated. 15" x 6" Jayco branded rims (rated to 1000kg each)

7) make. ( Jayco )

8) model. ( Camper, as stated on my current rego form )

9) secondary plate VIN. ( as per the current VIN )

10) ATM. ( revised to 2500kg )

11) Tare, which isn't compulsory ( revised to the new figure once weighed )

12) manufacturer. ( This will be myself ) this is where you need to be comfortable with the chassis being capable of your ATM increase as you are now considered the manufacturer. I'm trying to communicate with Jayco on this topic and hope to get some sort of letter stating that the weight increase is acceptable as we are only talking 228kg over the original ATM of 2272kg. This is in hope mind you!!!


Yet to be confirmed is my axle load rating but the paper work Jayco supplied (original work order) has each axle rated at 1450kg and the axle group load capacity at 2700kg.


Hoping this will pan out and will keep you all posted. Seems like a long winded process but 20mins confirming most of the above list and a 10min phone call with said "nice chap" seems to have me at the point of confirming my axle group, filling in the form stating the above info is correct and having it inspected at the appropriate local license guy. It is my understanding once he confirms the caravan suspension ect is good he will state the new Tare and requested ATM on the inspection form and I'm off to the dot. From here I can purchase a blank plate from Martins trailer parts and fill in as per my new license papers and fix the secondary plate the van next to the existing compliance plate.
The secondary plate is noted in the licensing system along with me as the manufacturer so if I'm pulled up and checked it will be visible to the inspector via the dot network.

Cheers Max,
 

dagree

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Mar 3, 2012
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Some interesting and helpful information there @Herbertclan. :encouragement:
Could be something I might look into if/when I upgrade the Prado but with a current ATM of 2433KG's I don't think I'll get any benefit from a 67KG ATM upgrade 8-) ...... But keeping this in the memory banks "Just in Case" I NEED to take more away!!!!!
 

Herbertclan

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Mar 6, 2016
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Hi all,

Still chipping away at this, the guy that will be doing the inspection called today and we went over my requests, he also confirmed the secondary compliance plate was correct and the way to go for an ATM increase. While it isn't a requirement at this point he suggested a letter from ALKO stating the rating of my suspension. I have measured and trolled the ALKO web site and downloaded there tech info and managed to find my axle, springs and brakes for my van where they publish the recommended weights and capacity of my components. This info along with the brake part number is a requirement for my application so this ticked two things off my list.

Through the sea of varying weights and figures I think I'm on the right track!
Info for those interested.

1) My springs are ALKO 6 leaf, 60mm rocker tandem axle springs. Spring eye to eye is 700mm and leafs are 6mm thick. This group is rated by ALKO to 1500kg per axle.

2) my axles are 45mm square with 45mm round stubs in an overlay configuration (slimline) rated to a maximum 1450kgs on 14" wheels, maximum of 1200kg on 16" wheels. I believe this is where the Jayco grey area starts as I have 15" wheels and believe this is why my axle group loading is rated to 2700kg (1350kg per axle) I thought it was a simple split between weight differences but this would work out to be and axle loading of 1325kg per axle and a total of 2650kg??

3) the third link in the chain is the electric brakes, the 10" x 2 1/4" ALKO (off road) electric brakes are rated to 1600kg on 14" rims and 1400kg on 15"-16" rims per axle (total of 2800kg).

On paper it looks like the axle group is the lightest rated component and is what appears to be dictating the axle group load. I also got the latest form and info sheets for the process today and will try and load these up if anyone is interested?

At this point the cost is my time trolling the net and making calls, $50-$60 for the re-examination, the cost of the weigh bridge docket ($35) and presumably a slight increase in rego due to the new ATM. I'm sure Col is going to hold his hand out at some point but unsure of what that could be??


Cheers Max,
 

Crusty181

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Feb 7, 2010
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@Herbertclan Terrific information well done and thanks for posting up such a comprehensive explanation. I presume because of the Aust STDs and the design rules it would likely be applicable Aust wide.

You have gone above and beyond with this Deep Diving. (You've also won the use of high level corporate speak Deep Diving)
 

Dobbie

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Jun 18, 2014
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Yep. I agree.

A comprehensive and considered investigation.

(We are waiting on a new van and investigated an ATM upgrade at time of manufacture....now. They quoted axle rating, tyre specs, suspension details etc etc and flatly refused to do it but offered the option of a suspension, axle upgrade in the build process. We considered it and rejected it as we wanted to keep it simple. But it did encourage us that they actually knew what they were doing....and we avoided having to go cap in hand after the build)

At least we don't have to do the above!

and I understand why they wanted info on the electric brake requirement....I didn't have a clue!

8-)8-)
 
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bigcol

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Nov 22, 2012
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@Herbertclan , Max, tis a wonderful thing you are on the way to achieving

While it isn't a requirement at this point he suggested a letter from ALKO stating the rating of my suspension.

I would hazard a guess that, if you have it in writing from ALKO what the designated ratting is, there could be no argument with what is being done

good job mate, well done that man


yes, once you have had it all sorted out
a thorough run down of the hoops and swings you had to do would be great
 
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Herbertclan

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Mar 6, 2016
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Thanks for the kind words everyone.

I'm not there yet but tomorrow is the day!! I called ALKO this morning and spoke to them regarding the displayed axle group load rating of 2700kg. After a chat, waiting on hold for a little bit, the ALKO guy came back and said that they supply the parts as individual components and Jayco put it together BUT if it has 2700kg stated on the compliance plate it was most likely a figure the ALKO engineers calculated on Jayco's behalf. He went on to say that on request this type of thing happens (presumably high volume customers like Jayco) when there aren't clear specifics written, i.e. 15" tyre option as ALKO state a rating for 14" and 16" but not 15"?

In short as I presumed in the above post, the engineers look at the max rating 1450kg and the minimum rating 1200kg and draw a line somewhere in the middle and settle on a figure in the middle somewhere.

Here's hoping tomorrow is a red letter day!!

Cheers Max.
 

Herbertclan

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Mar 6, 2016
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@Herbertclan Terrific information well done and thanks for posting up such a comprehensive explanation. I presume because of the Aust STDs and the design rules it would likely be applicable Aust wide.

You have gone above and beyond with this Deep Diving. (You've also won the use of high level corporate speak Deep Diving)

Thanks @Crusty181,

I'm not 100% sure on the Australia wide thing, but if I remember I will query it with the licensing guy. I would look at from this point of view though. While we are all required to "sing off the same song sheet" each state or territory will likely have us all going for their respective goal posts. This is IF I'm reading your post correctly??

If you mean "will I be legal" to run with my (hopefully revised) ATM nation wide then I'm sure I'm fine their based on every one using the VSB1 guidelines nation wide.

If I move to another state and register our revised van then I'm sure things will definitely need to be applicable to the new state/territory.

Cheers Max.
 

Herbertclan

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Mar 6, 2016
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And it's official:)

Went and had the inspection this morning and all is sorted and passed with no worries, I have successfully upgraded my ATM from 2272kg to 2500kg. Rego is due this month so I wanted to get this sorted prior to paying the renewal. My rego papers will now reflect the new Tare and ATM once the rego is payed, I still have to fit the new secondary plate and will have this engraved this weekend and fit that in the boot.
Once I have the plate engraved I will post up the pictures and info I have gathered while getting this sorted.

The corrected cost of doing this is $25.00 for the weigh bridge ticket for the new Tare, $65.30 for the inspection fee done this morning and 11million hrs trolling the net for info on my suspension and looking for anyone who had done the secondary plate upgrade.

while my suspension is well above the weight I requested, I was mindful that my vehicle is only good to tow 2500kg. With my Tare at 1950kg now and my ATM at 2500kg I'm more than happy with the increase. I was also mindful of what increased weight could do to the chassis and towing characteristics.

One of the obvious things that came out of this, is that if I ever get a new van I will be sure to do the following.
1) get all of my options ex factory.
2) ensure I have a weigh bridge docket to confirm the tare and empty drawbar weight from the factory.
3) if the factory isn't able to do my options, ensure the dealer doing them addresses the change in tare and ATM as part of the purchase contract.
4) get a definitive answer from the factory on what you caravan could actually carry (all weights, ATM drawbar ect) and get that in writing.

Cheers Max,
 

Herbertclan

Well-Known Member
Mar 6, 2016
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Well done Max :clap2: ...... Opened a can of worms for the dealers when they say that it can't be done ;)

To be honest I think they are simply not interested in being bombarded with caravaners looking at doing upgrades and not looking at a bigger van. Probably has no economical benifit for them or the OEM. It took a bit of time researching but once I knew which direction to focus on it wasn't too bad and things started to fall into place.

One must remember that this option has me as the manufacture on the secondary plate of my caravan. if I had a bigger 20ft-22ft OB Jayco I would of looked at raising my ATM a little more measured as far as chassis strength goes. Mine being the smaller of the tandem models I felt the chassis is more than capable to carry the extra 228kgs I was looking for.


Cheers Max,