Have a barrel each of SAE 30W, and SAE 50W meeting the TO-4 specifications. I know the 50W is the same as 90W gear lube on another scale but I'm wondering if th 30W would be good for my older Allis power shift transmission. Oil I have purchased earlier is a 10W-30 viscosity meeting the same TO-4 specifications. Thoughts?
If it was a CAT, it would take 30w in the transmission and 50w in the finals. Your AC owners manual should give you some direction. It may use a 10w oil.
It might depend on the temps. you're running the Allis in.
Nope. The Fiat-Allis recommendation is for SAE 10W engine oil for the powershift transmission. You can also use ATF, "Type A - Suffix A". The specifications are on Page 8 of the service manual (link below). https://www.tractorparts.com/PDFs/AC_HD11B_PWRSHFTTRANSMISSION_SERVICE.pdf
It's odd it lists ATF for cold temps. but doesn't list a thicker oil for hot temps. My grader calls for 10W but above 30C you can use 30W. I think some Cat trans. are similar. Mind you not too many locals are always above 30C.
That is the same manual I have and has been followed. The current oil installed many years is a 10W-30 viscosity blend and my prior purchase is the same so was planning that till my cousin mentioned these. I've ran the 50W in Roadranger, and Mack manual transmissions for years without problems. I just wasn't certain about using the straight weight 30 oil in the transmission and steering clutches. Think I'll retain the 50W and return the 30W. No direct plans for winter use at this writing so that wasn't really a concern. Thanks
There were a lot of substitute oils that worked in the old Allisons. I don't have any experience with the old Euclid and Terex transmissions so I'm unfamiliar with the use of multi-vis oil in them. When you run the Hydraulic Transmission Fluid 10w specs forward, you still have a C3/C4 10, TO-4 10 or TDTO 10 spec. There's no multi-vis spec called out for your old Allison. I don't see how running a 10-30w (at 30w) oil will be good for it when straight 10w is still called for. Just throwing that out there for food for thought.
He's talking about Allis Chalmers not Allison transmissions. May be similar oil requirements though.
HD Transmission Fluid with a C-1 10w spec is an Allison creation.