What type of vehicle? possibly broken parking paw (not good) if it will park but shifter just wont stay you have a broken shifter safety switch (this is the switch that requires you to depress the brake to shift from park) if it is an older vehicle it is a broken shifter the button you press to shift is broken if it is your parking paw you will need a different transmission or take it to a transmission shop to have it worked on (paking paw is a small knob inside the transmission to keep the vehiclke from rolling and coould be broken if you park on hills without using the parking brake)
it is probably that your shift lever bushings have worn out, but check the rubber seals and carpeting, sometimes they put pressure against the shifter making it pop out of gear.
needs adjustment most likely
Shifter Assy has a cover with just clips. stick a flat screw driver and pop it open. remove the ashtray wire and look on the passender side of the shifter their is a small bar that when you push the button INN on the shifter moves. usually this small rod (Bar) will move to the driver side move it left and right to find the correct possition and release the shiter. Eventuly you will have to replace the whole shifter Assy.
depress brake pedal while attempting to put the vehicle into gear. retard
Check the transmission linkage to make sure that it is adjusted properly. Some vehicles have an indention or catch in the vehicle where the shifter handle is. Make sure that it is working properly.
This happened once to my van. There is a pin inside the transmission that locks the wheels when the shifter is in "Park". That pin had broken off and was bouncing around inside the transmission and eventually jammed it so that the shifter was stuck in "Drive". I had the get my transmission rebuilt. I hope yours is a simpler problem. Perhaps there is a simple problem with the linkage between the steering column and the outside of the transmission.
LOL, I wonder why anyone would even have to ask... but anyways, most likely you need to adjust the linkage.. Otherwise sounds like you should read the owners manual for the next car you drive so you don't destroy yet another tanny.
no
CHECK YOUR TRANNY SHIFTER PLATE ON DRIVER SIDE PART OF THE TRANSMISSION , SEE IF IT LOOSE, THE LEVER IS CONECTED TO A BOLT THAT CONTROLS THE GEAR PISTON THAT SHIFTS GEARS , IF YOU CAN SHIFT THE GEARS BUT DONT HEAR A CLICK , THAT MEANS THE BOLT ON THE OPPOSITE SIDE OF THE SHIFTER PLATE ON THE INSIDE OF THE PAN IS LOOSE OR MAY HAVE COME OFF AND YOUR TRANNY WILL NOT SHIFT AND STAY IN PARK ......IF THAT HAPPENS , AND YOUR NOT HIP TO WORKING ON TRANNYS , BRING IT IN OR TOW IT, IF YOU DO UNDERSTAND SOMETHING ABOUT TRANNYS , DRAIN THE FLUID PULL THE PAN OFF AND YOU WILL SEE WHAT IM TALKING ABOUT ..HOPE I HELP ALITTLE IF THIS DOSENT EVEN PERTAIN TO YOUR QUESTION SORRY ABOUT WAISTIN YOUR TIME...
if u are in a high gear no shift down because if u stay in the same high gear u will loose rpm as the car skids sideways causing a shorter drift.
fifth gear and the related components need to be replaced
A vacuum leak can do that. Check the gasket at the base of the throttle body for a vacuum leak.