I do like the idea of running it for a while and then draining the gearcase and putting in fresh 80-90. I'll probably do that as well. My question isn't so much about whether or not the chain will wear out so much as I'm wondering how things will change as the chain stretches a bit. We know the old sprocket system had a (bad) way of adding some tension to the chain as it stretched, I can't see (from the outside) how a tensioner might have been included inside the case.A clean chain in a constant gear oil bath should last 10X longer than an exposed (dirty) chain that periodically gets a shot of some kind of lube. Keep in mind that even folks who give it a regular shot of lube probably aren't doing it correctly. It's tough to get lube where it needs to be to actually do some good (inside the rollers) and JD didn't make accessing the open chain very easy. And then there are those who have the chain too tight due to the eccentric sprockets.
For maximum life of the gear case, it might not be a bad idea to run it for a while and then drain and refill with oil. That should flush out any contaminants from the manufacturing and assembly process.
I live just north of Fargo, ND and while our 10 day forecast is pretty warm and sunny (highs in the 20s and 30s!) there is good opportunity for heavy wet snow in March around here. If that doesn't work I've got a minimum of 12" of snow on the ground with drifts up to 5' in some areas, I can take a little time to give this thing a workout if need be.I doubt we will get to much snow now until the real spring here??? I hope we do get some so I can use this and yes I was going to drain the gearcase before it gets put to bed regardless. It has been run for about 30 minutes.. I went for a ride and had the blower on but no real way to "push" it.. There was some oil in the case when I opened the fill so who knows what that was. Like I stated, it didn't take much oil at all. Have a good one,, I ordered the spare 2 days ago and it's at the UPS stable ready to be loaded on the truck 25 miles from me. Fast, free shipping. Like I said great company to deal with and if you have a question you get an answer in minutes. You can't beat that. Not knocking our vendors by any stretch just my experience with this new gearcase. Jeff