In 25 years of running a road grader, I've only pushed snow once without chains. Swore I'd not do that again. Beyond improving the machine's ability to push thru snow drifts, chains come in very handy when turning around in a field entrance or if you get too close to a ditch and slide in or a number of other scenarios. Stopping a 40K lb machine going downhill with only rear wheel brakes and no chains is a story in itself.
I always chain all four rears. The final drive in the tandem is roller chain driven. There's a double sprocket on the transaxle output shaft that enters the tandem drive. This double sprocket drives each tire with an additional roller chain, one going forward, one going rearward. Let's say I put a chain on the rear tire only. 90% of the driving force is now being absorbed by that single roller chain inside the tandem drive. The unchained tire is basically just along to carry weight. The Grader is not designed to handle that stress constantly. Would be like having the tandem oscillated to the bump stop and the other tire hanging in the air. Would you drive around in that situation??
I've ran chains on the front, non drive tires as well when on very slick snow pack or ice pack. Don't need to that quite as much with newer equipment. I run 17.5 tires rather than the standard 14. That helps a lot too.
I have a hydraulic angle snow blade for the front but never use it. I've got a very large V-plow that I use if roads are drifted badly.
I push snow at 15-18 mph depending on the situation. I've pushed 3 times this Winter, all three on very dry snow. You can haul butt when pushing that with little worry about bounce. Yep, angled front blade, trying to take a sharp corner at 15mph can be a bit treacherous.
I have only went in the ditch once. That was my second Winter. Went around a sharp, 90 degree corner to the right. Had the moldboard pushing snow to the right. Front tires started sliding. I kinda freaked out and stuffed the blade into the ground to stop me. Of course the ground was frozen and it picked the front tires off the ground and over the bank I went. Road was elevated about 8 feet. Steep bank ending in bean field. Small trees 3-6" diameter. Mowed a hole thru them and stopped in the field. I went a little slower the rest of that night.
