If it's new, use the Sno-Way oil to prevent any hassles over your warranty. If it's used, find a source for synthetic ATF and run that. I use Amsoil ATF in all three of ours and can't see any difference other than the cost.
It is a used plow. I did a search finally( sorry plowking) and read that you (Alan) use Amsoil ATF. This is what I will try and find. The fluid that was in it was red so I asume it wasn't the hydro oil. Would Artic Blue work? The local plow shop sells this.
Sno-Way fluid is Type 5606 this is rated at -60 if not available can use Exxon Univis J13 or compatible. So the answer is anything can be used as long as it crosses over to the Type 5606 especially if you are just adding to the fluid and not draining the entire system. ATF is not recommeded.
For the past three years I've been running only Amsoil ATF. This is in plows that log many hours of use. No problems that I can see. Our oldest plow was bought in 94 and we've run ATF in that one since about 96, first regular ATF and since 98, Amsoil. While there may be some benefit to the factory oil, being rated to -60 is doubtful, in my opinion. For one thing it has never gotten to -60 around here, and secondly, how cold is it when it's snowing, usually in the 20s and rarely in the teens. All I can say it that it works for me, so I'll keep right on using ATF.
J.Henderson, I am simply stating what the factory specifications call for. If Alan has been running Amsoil ATF for years that is fine, but I cannot recommend it because I work for Sno-Way. You may want to consult your local dealer regarding the ramifications or using alternative hydraulic fluid verses 5606 type fluid.
there is an Exxon dist. in Burlington,IA. Valley Dist. 319-752-6666 and there is a Sno-Way dealer in Moline,IL Quad City Spring 309-762-2956 for the 5606 fluid or check out our dealers on our website at www.snoway.com As for the amsoil, couldn't find anyone close to you. You may also try a Napa store for cross over products to the 5606 or Exxon Univis J13.