[Dave at Pelican Parts]

Since you said "the gear stick", I will assume that you have a manual transmission. If you have an auto, things are fairly different.

Problems with several gears at once are often related to the clutch, instead of the gearbox itself. If the clutch is not releasing all the way, you could get symptoms like this. Does the pedal feel normal, or is it spongy or extra-soft? Does the pedal get firmer if you pump it several times in a row? If so, that would indicate air in the hydraulic system for the clutch.

The clutch should be self-adjusting (that's part of the point of hydraulic clutches, after all!), so a problem releasing indicates something more serious than just being out of adjustment.

Try bleeding the clutch, or flushing all new fluid through it if it's been more than a couple of years since that was last done. There should be a way to do that, but I haven't looked into that procedure yet for my car, which is still in the "pre-paid maintenance" period.

The shift linkage, the cables that go from the gear shift lever to the transmission, could also be out of adjustment or have gotten messed up somehow. If, for instance, the cable sheath comes loose from where it is mounted, the motion of the lever will not be accurately transmitted to the bits in the transmission that select the gears. Does the gear lever feel strange, other than just not wanting to go into gear?

Changing the transmission fluid may also help, depending on what is going on in the transmission. I personally don't buy that the fluid is "lifetime" in that you never should change it at all. It may have a long life, but I don't think there is any automotive fluid that should never be changed. Also, changing the fluid gives you a chance to look at what comes out to see if there is any debris in the fluid. That could indicate damage inside the transmission.

Sorry to not be very specific, but I'm operating on general automotive knowledge because I haven't dug into my 2012 MINI yet.

--DD