There are many reasons why a transmission may not engage. Since the question is not more specific, here are a couple possibilities: If it's an automatic transmission, and you are unable to move the shifter, the problem could be caused by the neutral lockout switch or the release relay. If the shifter can move into position but the transmission won't engage, it could be, 1)low fluid, 2) the hydraulic pump, 3) the internal valve body, 4) internal seals, 5) the clutch pack. If it's a stick shift and you aren't able to shift into gear with the engine running but it shifts when the engine is off, the clutch isn't disengaging. If it goes into gear but nothing happens when you let out the clutch, the clutch is worn out. There are other possibilities, but that's an overview of some of the possibilities.
Dont change gear and just hope you don't have to go faster than 40mph.
if spedo dont work ether its a speed sensor
you gorget to say, what transmission you have. in gear dont say much. sorry? Bad transmission? Bad clutch?
There are several things that can cause your automatic transmission not to go into first gear. The most common cause is low transmission fluid.
you dont, just drop it in gear real fast
Because your transmission is broken. When a car wont go into gear(s) there is something wrong with the linkage, the transmission control system ( electronics on some newer vehicles ), the clutch or the the transmission itself.
on the transmission. and it requires gear oil
There can be several things that will cause your transmission not go into reverse. The most common cause is the gear in the transmission is worn.
you dont put transmission fluid in a manual transmission. you need gear oil, and it should be done by a transmission shop
Transmission is going
the transmission is failling or starting to go bad so get it fixed or get a new transmission the transmission is going bad
When a vehicle does not go into gear when it is shifted from park to drive, it is usually due to transmission issues. If it has a manual transmission the gears may be stripped, if it is automatic then the transmission may have overheated.