Chevrolet MCP 3 Ton Lorries G.S. (Australian)

[motto]

Lionel, if the wheels on your truck are the stock, standard Chev 20" type of that era with a lock ring that is full circle, (not split like a cir clip) and they are in good shape then they are quite safe to use.
As I posted on another forum recently, GM and Studebaker between them built around 800,000 6x6 trucks during WW2 (These used the same lock ring arrangement as the Chev 20" wheels we are discussing). This gives a total of 8,000,000 wheels. Add another 800,000 spares and those produced for other trucks such as the Yankee Joe and we must be up around 10,000,000. Yes that's 10 million 20" wheels.
I have yet to hear of one failing.That doesn't mean that it hasn't happened in the intervening 70 years but if so it would be an exceedingly rare event.
As regards the question of what license is needed to drive this class of truck it would quite likely vary from state to state. In Victoria you can drive a vehicle up to 4.5 ton Gross Vehicle Mass on a car license. Strangely enough you can also tow a trailer up to 9 ton GVM subject to the capacity of the tow vehicle.
I have a friend that was pulled over by an RTA official whilst driving his Studebaker 6x6 and asked for his license. The RTA bloke said that the truck could not be driven on a car licence as it exceeded 4.5 ton gross and the friend tried to tell him it was only a 2-1/2 ton truck and pointed out that it said so on the dash plate. The limb of the law didn't agree with that explanation.

David

[Lionelgee]

Hello Grant and David,

thank you both for your extensive information about my rims. I will take a couple of photographs - once the camera's batteries charge. Then I will post them up.

How readily available in Australia are the 7 x 20 tyres - 8 ply?

Kind Regards
Lionel

[Lionelgee]

Hello All,

I have just loaded up three photographs of the wheel rim - a couple of which are close-ups. It looks like the ring is in a single piece and it seems like an over-sized circlip.

The rims have a patina on them which will hopefully come good once they get sandblasted and painted again.

I circled the lock part of the rings - luckily it was at the top of the tyre so they were easy to photograph. BTW this tyre is one of the better ones I have .

Kind Regards
Lionel

[motto]

7.50 - 20 tyres are more common than 7.00 - 20 but they are still not common. If you started looking you would probably turn some up.
That type of wheel lock ring I am not familiar with and I have not seen them on a Chev. The L/L Chev lock ring was a complete circle. These wheels must pre date that style. As stated earlier, I am not familiar with what was around before the '42 model or after for that matter.

David

[Grant Bowker]

Sitting here in Canada, I have to admit ignorance of the Australian vintage tyre market.
Based on a quick search, there seem to be some sellers in Australia, see
http://www.hcvc.com.au/forum/salewan...es-or-7-00-x20
http://www.antiquetyres.com.au/20700-0
http://www.oldworldlamps.net/tyres_20_inch_16.html

They certainly exist in USA at Coker Tire among others
https://www.cokertire.com/tires/styl...m_diameter=120

Keep in mind that you may not need to limit your search to 8 ply or PR (ply rated as opposed to real plies) tyres, you might get away with 6PR provided they have enough weight capacity and you should be able to use 10PR (or more). If using 10 PR, see if you can get hold of load/inflation tables for the tires. You should be able to run a lower than "rated" pressure as you are also likely carrying a lower than rated load per tyre but without the manufacturer's tables it is hard to guess how much the pressure can be reduced safely. It would likely also work to go up to 750-20 size if that's more readily available. There is a chance the extra width might rub somewhere but my guess is that the chance is small and I doubt the extra 7% width would be obvious.

Looking at your photos, unless there is an illusion happening, I would want to check the condition of the ring in the photo with both red and white circles as it looks as if it might be bent enough to not seat as well as desired. But - if the tyre is just pushed away from the ring, all might be OK.

[Lionelgee]

Hello Grant and David,

Thank you for more information. Especially to the links to possible retailers, in Australia and abroad.

Kind Regards
Lionel