Here's my update to all the repair fun I've had. I will post pics in the next entry to help. But for now here's the words. As per my original post, I cracked the left side housing plate (not the main diff housing that hosts the pinion gear). I went online to CFMOTOwarehouse.com (also named Brolin parts LLC). The website says shipping in 6-14 days. I ended up modifying my purchase a week later to add an oil seal which I should have known to buy in the first case. But the rep was helpful in general and responsive to phone calls. However, it still took a little over 3 weeks to show up. not quite Amazon prime speed. But oh well. I then proceeded to get the differential out. The service manual I purchased online was less than useful in that it had little info on removal process. It basically said remove the axle and applicable parts. thanks... But removing the axles were not too challenging. It took a long breaker bar and some heat to get the axle nut off but it worked. The process was not much different than other vehicles so Youtube helped here. The axles popped out of the differential with a little maneuvering but not too much that I was worried about messing up the CV joints. I did learn that if you must remove the brake calipers then be careful the break piston will close and thus later it was harder to insert the rotor back. but that's break job 101 re-learned again. But here's where the real fun started. there are 4 bolts on the housing. But there are also mounting brackets that must come off too. you can't get to all of the nuts/bolts without removing the upper suspension arms. And then I had to remove the sway bar as well. Oh well, just gave me an opportunity to re-grease everything. Then you need to remove the Hex bolts on the front of the diff connecting to drive shaft. It's hard to get to these things without the perfect tools and being a contortionist. my socket wrench was just about 1/4 too long to fit between the bolts and the opposite bolts to the engine housing. But I figured out a minor hack by using my hex socket and a ratcheting flat wrench inserted between the socket and the bolt. OK, so now I have the differential free and ready to be removed straight out the back. But it doesn't fit. no matter how I turned it I couldn't get it out. the opening space in the main frame was about 1/32 inches too small. I don't know if this was supposed to be large enough or that my frame was not toleranced the best or I just didn't turn the diff the right way. So I ended up removing the left (cracked) housing cover (8 bolts I recall) and then removed both main pieces separately. Don't forget to remove the old diff oil first... it was still a little messy just the same. But now I can inspect the diff and I found that I had metal shavings from some damage to the gears. So now I'm stuck with a dilemma. Are they damaged enough to want to swap those out and also deal with re-shimming the whole thing. or just put it back together and wait until the whole thing breaks again. Rather than risk braking while 30 miles out in the desert somewhere, I decided to buy a whole new differential. The comparison cost was roughly 350 spent on replacement parts and maybe 200 to get a local mechanic to re-shim it for me. it's an art not a science and one local mechanic didn't have any experience. or 900 for a totally new one. Also note that CFMOTO changed the design. the new housings are "beefier". it was obvious that they improved the housing design to make them stronger. I suspect because the housing were cracking like mine did under normal use. So having a new one that might last longer pushed me over the edge. In the process, I started talking to a local dealership who offered me a differential at the same price as I could get it online. And they said it would ship in 4-6 days. It was the dealership in Fort Collins CO. Kudos to them and nice folks too!! So for the first time ever I will buy parts from a dealership (like the old days...). One thing to note about the new part and if you ever replace something on them in the future. there's a little air port on the left side housing. this is pressure fit and you will likely ruin it if you try to swap it. So if you just replace the housing, you need to buy this as well. there's also a plate inside, but these can be swapped. Finally the new part has additional "ports" on the left side housing. one set of ports go into the boot housing. these are not present in the 2018 part. there is no hose or anything here so don't worry about it. but there's another threaded port into the interior. The replacement differential came with a bolt screwed into that. It's maybe another viewing port or oil port, but it wasn't clear. but the replacement left housing from online didn't come with it. That confused me when I got it and I would have needed to figure out a correct bolt to fit there. In any case, now I was ready to put it back into the vehicle. I had to do the reverse in that I had to install the left housing after I inserted the main part of the diff into the gap in the frame. kind of a pain but oh well. The rest of the install had some minor challenges but mostly due to my lack of true mechanic skills and thinking through the right sequence of bolts to install. start front to back... Once I got it all back together, I drove it around the neighborhood to discover that another issue I was having just got worse. It's having troubling shifting out of gear and into reverse. So I've got to do some reading on that and I suspect I'm not going to like it.