2008 Mammoth 800 trans problem

[Jhodges88]

I recently purchased a used 2008 Mammoth 800. Only had it a few weeks. At first all the gears were shifting fine. Now I am having trouble with the trans staying in Low Gear. Just a little bit after I take off in low, it pops out of gear into Neutral. The High and Reverse gears are working just fine. I called a parts dealer and he told me that he thought it was the trans main gear assembly. He said the first generation gear assemblies were defective. I'm not exactly sure what is causing this. I was hoping someone on here might be able to help. Any advice would be greatly appreciated!
Thanks

[katoranger]

I can't really help, but from a quick google search it appears that it is a copy of the older Polaris Ranger.

One thing I would check would be any shift linkage/cable for adjustments. It may not be fully engaging into low range.