Kanzaki KM2A Trans Oil - SAE 20 or 30 - sources/brands?

[AMcC]

I have a Yanmar 1GM with a Kanzaki KM2A trans that says it needs SAE 20/30 HD oil. I reached out to Yanmar through their website to ask about current oils for the trans, and they wrote back:

"The KM2A gear will use an SAE20 or and SAE30 HD (Heavy Duty) engine oil. Back when this was written, this what was showing available to purchase. Today it would still be the same, but without the HD, but you would want an SAE 20 or SAE 30 diesel engine oil to be used. It cannot be a multi-viscosity oil as it has additives which will not work well in this gear."

So, I'm looking around online for an SAE 20 or 30 oil, and have found Shell Rotella T1 SAE 30, and Briggs & Stratton SAE 30 engine oil, but no SAE 20. Any tips on Shell vs. Briggs, or anyone source SAE mono grade 20 oil from another company? My trans is slipping, and I'm hoping the right oil and checking the throw on the lever will put off pulling the trans until next winter...

Thanks.
-Alec

[Frenchy]

Alec, you might have checked this already, but don't overfill the transmission. If you do, it can cause slipping. Fill to
the mark and no more. I think the Rotella SAE 30 should work fine, since that is recommended. Good luck. - Jean