engage parking brake all da way; put it in low, rev the engine .. don't float da valves! ; and if da shifter slams all over da place, suspect the mounts. btw the shifter will move quite a bit even with good mounts, but a bad one will show up.... ... look under while someone does it and try not to get rolled over; I do same /motor mounts....
As Joe advised Check for Codes.... an iffy MLPS can do this too esp w/intermittent hard shifts.
As Joe advised Check for Codes.... an iffy MLPS can do this too esp w/intermittent hard shifts.