Just got my k15 back from the shop to fix the gear oil leak from both boxes, a few new shift forks and a input shaft sleeve later its much better and a good bit tighter, unfortunately its still having its weird 4th gear thunk. Im curious if anyone might have an idea what it could be? Transmission shop says they couldn't find anything to be causing it. It sounds like something is smacking against the case itself, you can hear it coming through the shifters. Some days its a little deeper, other its a bit higher pitched