Hello my name is pat, just picked up a 91 fourtrax300fw. It’s been rolled so it needs some cosmetic help. So my son and I already straightened the racks a bit. Next will be changing out the front left upper control arm. And we changed the oil. So my first concern is that the threads for the oil plug felt a little funny when we put it back in. Feels like they are about to strip out. I’m pretty handy with tools and am looking for the best option for the next time I pull the plug. If the threads are wiped out what are my options??? Aside from splitting the case. I here there not much material for a heli coil so I’m a little nervous as to what to do. Also what oil do you guys recommend for the from and rear diff, as well as the transfer case. Also looking for affordable tire options. Machine seems to run out great. The idle was a bit high so I turned it down and I’m hoping that will help with the hard shifting?? Also adjusted the rear brakes but how hard is it to change the rear shoes? Thanks in advance for any help and advice.