2001 tacoma 2.4L Manual transmission. has about 90k on it. It grinds occasionally going into first gear from a stop and just today it started doing the same thing going into 4th. Also, it has started to slip out of gear on me. I'll be driving along, let up on the gas a little and it shifts back into neutral all on it's own. Any thoughts or advice would be greatly appreciated. I don't mind tinkering on it myself but if the tranny has to get dropped, I'm not interested in doing it myself. Any quick fixes??? Thanks in advance.