When I shift into 5th the car jumps and it wants to pop out of gear when I push on gas pedal
My car has 142743 miles.
My car has a manual transmission.
This suggests you may have a worn or failing 5th gear synchronizer in your transmission. As you may know, when a clutch drags, it is not letting go of the disk fully which overloads the synchros and burns up the friction surfaces quickly. Synchros work by speeding up or slowing down the input shaft and clutch disk by acting like a brake. If the clutch is dragging, the synchro friction surface is trying to speed up and slow down the engine’s mass, which is impossible. When this happens, you may experience the transmission trying to pop out of certain gears as you describe. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your transmission.
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