with my 33, when i clutch down from fully engaged, sometimes i can feel my engine 'jump'. it sounds like a dull rebound sound and i can feel the engine/box jolt. At high revs, it makes me misshift because it seems like the H pattern is slightly off its usual position (like putting in 3rd, instead of pushing the lever straight up, I have to move the lever slightly to the left then push up). could this be a clutch problem, or a collapsed gearbox/ engine mount etc?