Transmission / Overdrive: GL-1 90 gear oil ‘50 champion

[Flthdchamp]

Hello,
I know the manual transmission uses a non-hypoid gear oil, but should it contain friction modifiers? Or is this something that is also only applicable to hypoid gears?
Thx

[Hallabutt]

I don't use anything but GL-1. It seems to work find as is. I would presume that your 50 Champion has survived on a steady diet of it for seventy years. The time to experiment is when you have a problem. If you don't have a problem why take the chance.

[BobPalma]

Yep. NAPA #65-201 for a one-gallon jug. BP

[Flthdchamp]

Thx guys, the previous owner was running SAE 40 but I’d rather run GL-1. I’ve only owned the vehicle for a few months. The transmission has no issues but the previous owner also put very few miles on it. I found a GL-1 with no extreme pressure additives but it also listed no friction modifiers. I wasn’t sure if that mattered.
Here is the product link:
https://petroleumservicecompany.com/...1-gallon-case/

looks ok to me but wanted a second opinion.
thx

[StudeRich]

The Two "Terms" are describing the Same properties. That more "Local" PSC Brand should be fine.

[Flthdchamp]

Thanks for checking, I agree

[NCDave51]

And I hadn't known before I joined the SDC and this had become a topic that SAE 40 engine oil is in the same viscosity range as SAE85W90 gear oil.

Yes, the key for the OD (if equipped) is not having hypoid additives that 1) attack yellow metals or 2) lower friction in the OD components to the point of poor engagement. Some friction is required in the rollers/ramps/sungear.