Hello and strange ratio Timken Diff.

[tunnow]

Hi everyone , I have just become a member of The Barn this last week. I am from New Zealand and am in the process of restoring a 1941 1 Tonner, a truck I purchased some 30 years ago for a project come my retirement, that day has arrived and work has started. The Tonner was running when I bought it but was in a sad state of repair and had a very very slow diff in it although I reckon it would pull an Elephant off its nest, here is where I need advice, I have come across a 1 Tonne Timken diff identical to mine on outside appearance but the ratio is 2.6 to one, I have not been able to find anything like this ratio related to a Timken under a Tonner, would anyone be able to enlighten me on this. Tunnow

[Brian]

Welcome from a fellow Kiwi. 2.6:1 does not sound right...sure it's not 6.2:1? I consider a 41 tonner to be a good looking truck. Got any photos?

[tunnow]

Hi, thanks mate, I agree but the owner is adamant he says after checking twice that its 2.6, anyway he was asking $100 for it so I have bought it and pick up next week. Photos coming shortly, lots of work to do, cheers

[Mart]

I wonder if the owner has halved the number while checking. For instance if you jack up one wheel and turn it once you would get half the ratio at the drive shaft. You have to turn it twice to get the ratio.
Was a ratio in the region of 5.2 available on the tonners?
2.6 would be undriveable in a truck. Bonneville car, maybe, but truck, no.

I showed checking axle ratio in a video: https://youtu.be/bkvp3Fq21ZM

Mart.

[jimTN]

If it has the hubs on it yet, its a good buy. Just ask the number of teeth on the ring gear and pinion and do the math.

[tunnow]

Sponsored Links (Register now to hide all advertisements)

It does have the hubs and all brake components on it which as you say makes it worth it and Im quite keen to see it in the flesh .

[1952henry]

4.86 was standard, 4.11 were optional, but almost unheard of. I believe there was one in the 6s for the 4 cyinder.

[rotorwrench]

The gear tooth counts will tell the true story. I've never heard of any truck axle that tall. It would have to have a hell of an under drive brownie box to be able to pull a heavy load with that tall a numbers.

Chucks Trucks here in the US is the only outfit that has come up with a tall set of gears for the Timken Detroit rear axles. They are a 4.12:1 ratio set for the 1938 thru 1952 axles.

[1952henry]

At least on the later timkens there are 2 numbers stamped into the differential. Those are the ring/pinion tooth count. Quick division gives the ratio.

[Graeme / New Zealand]

Welcome Tunnow. We are a friendly bunch of f'ers here, quiet a few Kiwis too. Where are you? Please send photos of the truck when you can.

GB

[tunnow]

Hi Graeme, Im in New Plymouth and just waiting for parts to arrive for the truck, hoping to get some photos next week. Just a matter of pulling all parts out of the sheds they are in and mocking up the truck, cheers

[Graeme / New Zealand]

Know NP well was born there although I have resided most of my life in the Hutt Valley. Will look forward to the photos. They go down well on this site.

GB

[expavr]

Attached is Page 131 from the 1940 Ford sales manual which shows the axle ratios available for the 40 Tonner. I would assume this would hold true for the 1941 Tonner also. Welcome to the Barn and good luck with your project.

[tunnow]

Thank you expavr , I will solve the mystery tomorrow when I pick up the diff