Hey all, new to TT! Buddy of mine recommended me to join here and post up my prob to get some insight. I've checked a bunch of threads and bottom line is, if I want to attempt this job I need a shop manual, and access to some important tools which wouldn't be a problem for me. A brief description of the event: We were up near Caddilac, MI for some trail riding, put on about 50 miles that day, just finished up Lost Lake trail and were heading back to the trucks to call it a day. As soon as i turned onto the main road, got some acceleration, shifted into (i think) 3rd, made a sound like if someone was to turn the key in a car and start it while the car is already running... Heard it once, then a second time when I down shifted a couple 100 feet later and my back wheel locked up. Couldn't get it goin, or get it into neutral without rocking the bike back and forth to playing with the shifter to change gears. She starts, with the clutch pulled in. Slowly releasing the lever could get the bike goin, but can't really do too much with shifting or same thing happens, wheel locks up. Pushed the bastard the rest of the way, good thing it was about 1/2 a mile. Now, pretty much know that i need to split the cases and replace a gear or two or all ($$$) but to save as much on cost I would try to do it myself with the help of mechanically inclined friends who are also eager to learn. One thing I did was, I changed the tranny oil b4 this trip. Came out milky. According to certain threads, i may have a coolant leak... I also wanted to know if possibly replacing the oil with Castrol GTX 10W-30 (or 40 can't remember) would have been a cause for this incident... Any other insight would be appreciated. This is gonna be a winter project so gonna take my time and do it right. Thanks in advance.