It's been getting harder to shift gears lately...and if I shift real fast it grinds. I have found the only way to not have the gears grind when i shift is to wait a few seconds then shift. It doesnt do it in all the gears, mainly when i shift into first when a light turns green and shifting from 3 ---> 4. Also, I sometimes can't downshift to 2nd, it will just grind. A local truck accessory shop told me it was my transmission synchronizer (spelling?) that needed replacing. How much of a job is this? Is it an afternoon driveway project, 30min project, or a $$$ job? Thanks for the help, yall are awesome.