I was having a discussion with a guy with several D6 and D 8 machines. I ask about which oil he ran on his power shift. He said he runs rorella 15/40 in every box on the machine. TO-4 is high dollar but how detrimental is it to run 15/40 in the tranny?
Put it this way, if it was mine I wouldn't be running 15/40 in the transmission - but don't let that stop you. The best way to look at it is that good quality oil of the correct specification is the cheapest insurance policy you will ever buy for your machinery however "high dollar" you think it is.
Nothing like skimping on a $160 difference in oil throughout the entire machine. Spending dollars saving nickles.
How do you feel about A Dresser TD7G? The manual calls for engine oil, then goes on saying it must be a 10 weight oil of a specific OPEI designation. Wanting to use the best oil possible for the application, in hydraulics, and power shift transmission. I've bought HY-TRAN from Case/IH. I've read some good things about its formulation. It has friction modifiers for wet brakes, and clutches, emulsifiers to hold water in suspension where it is least harmful, and corrosion inhibitors. Any red flags about its use?
I think the thing to bear in mind, as I've posted before, is that there was a time in the past where manufacturers were trying to make "one size fit all" as far as lubricants went so that users could top up every system on a machine from the same drum. That's why manuals for machines manufactured in the period from the 60s to the 80s often offered a multitude of different oil options for each system on a machine, but the common one for every system is an engine oil. Over 50 years later the "one size fits all" approach has been proved not to work and we're now in the "horses for courses" mode where specific lubricants are receommended for specific systems. The problem for those who are operating older machinery is whether to follow the machine manual slavishly, ignoring all the advances in lubrication technology that have taken place over the last 50 years or so, or go looking for more lubricants that are the modern descendants of those that were recommended 50 years ago. One does have to be careful. For example a lot of older engines specify (and require) a monograde engine oil rather than the more common multigrades that exist in today's market and can suffer serious harm if the required oil is not used. Regarding your TD7G I'm sorry I have no idea. I have never worked with them. If you can post the oil spec from your manual I might be able to tell you more.