Newage gearbox - correct oil?

[bluebottle47]

Does anyone know what the correct lube oil is for the 40M box? The Winget service manual download - annoyingly - doesn't throw any light on the subject .....

My thanks in anticipation!

[martyn williams]

89 / 90 grade we used to use. But have seen some with 30 grade engine oil in them with no problems.
Martyn

[essexpete]

I would have thought a 80w90 gear oil.

[Fil]

Sorry for dragging this long-dead thread back to life, but I'm wondering if there are any more views on which oil is best to keep a Newage 40M gearbox in my Winget 2S happy?

The Winget manual I downloaded suggests you use the same oil as the engine (20W).
The only other reference I found was a cad drawing from Newage that suggested Mobilube SHC, which seems to be a fully synthetic 75w90 gear oil.

The modern Mobilube seems like the logical choice as it's specifically designed for gearboxes, but why did Winget specify 20W engine oil back in the 1960s/70s? Could the thicker 75W90 oil be too thick for this old gearbox and not get flung far enough inside to keep everything lubricated?

Any thoughts?

[cobbadog]

In a manual I have for a vintage 1954David Brown tractor it all comes down to the climate you are in. Here in Oz SAE30 works perfectly well in our climate. Co I would imagine that in colder climate it would be a bonus to have in the gearbox as 90 grade will be too thick and take a long time to warm up and allow smooth gear changes. In the final drives at the reduction gears they state only 90 grade gear oil.

[essexpete]

90 EP too thick for many gearboxes. I would go with the multi grade EP. Oils have moved on since the 60s.

[essexpete]

https://blog.amsoil.com/gear-oil-vs-engine-oil/
There is a viscosity comparison chart if you scroll down.

[Fil]

https://blog.amsoil.com/gear-oil-vs-engine-oil/
There is a viscosity comparison chart if you scroll down.

Now that's really helpful, thank you!

So looking at the chart and reading the article, it looks like the best option is probably a gear oil with viscosity around 75-85W, which cross-references to engine oil with a viscosity between 20W and 30W.
I'd rather have oil that's designed for gearboxes sloshing around in there than engine oil.

[gecko.cx]

90 EP too thick for many gearboxes. I would go with the multi grade EP. Oils have moved on since the 60s.

I don't know the box, but I'd guess it's mostly (entirely?) straight cut gears.
If that's the case, the EP additives will be unnecessary and may be detrimental to some alloys (bronze and white metal are both affected I think).
EP Additives are best avoided unless you need them.

[essexpete]

Yes I think Ian is right about bronze, EP not recommended for synchro gear boxes. I guess there could be bronze bushings in the old Newage.
Edit
The Morris Oils checker recommends the semi synthetic 75w 90 oil for the manual gearbox in a 3 ton Thwaites. Google oil checker for any well known brand. Some easier to use than others