Alright man if u go and u check ur shifter and its tight or u tighten it and u still have the problem im gonna tell ya its most likely that ur drivin with a out of balance flywheel...i had the same exact problem and i changed the flywheel and it went away...ur shifter moving when u give it gas is usually the case of a worn motor or tranny mount so check those too...preferably change them to polyurathane mounts...if u have alotta power the shifter may still move a lil when u give it gas...but alot of movement is usually the mounts. good luck bro
Alright...I am tired of going back and forth with you in PM's...time for a little basic Flywheel 101 and let others chime in and tell me if I am wrong or not......
Because the flywheel is bolted to the crank, an out of balance flywheel will cause the whole rotating assembly to shake. This in turn will cause the drivetrain and vehicle to shake as well if the imbalance is bad enough. Now before you go and argue this point, let me clarify one more point for you.... Ford only made a 28oz counterbalance or a 50oz counterbalance for the motors that are in mustangs since 1964 1/2 until now. That means that if you have a 5.0 motor, it'll require a 50 oz counterbalance(assuming you don't have a custom balance on your motor). If you took a flywheel from a '60's or '70's vintage mustang, which is a 28oz counterblance and bolted it to your 5.0, it'll shake the whole rotating assembly, drivetrain and car SITTING STILL
, when you bring the rpm's up.
Since the original poster said "When I am doing about 65mph the shifter is really vibrating"
and nothing about the engine shaking, it cannot be the flywheel. This means it can only be one of two things.... A. His shifter tower assembly is loose or
B. the plastic cup on the shift rail is slap wore out.
Now does it make sense? :laugh:
Tech Support(no not at a Firestone)
Tremec TKO Transmission Systems