Worn syncros, lack of lubricant, clutch adjustment,
the transmission is failling or starting to go bad so get it fixed or get a new transmission the transmission is going bad
To stop a standard transmission from grinding into third gear, check the level of the transmission fluid. If the noise continues, consult a mechanic.
if it is not going into gear when it is started, if it is a standard transmission then it could be that your clutch is not engaging or that your gears are stripped in the caseing of the transmission, if it is an automatic then your torque converter could be bad or there is something wrong with the shift linkage
There is no drive in a standard transmission car. In most cases you will have reverse, neutral, 1st gear, 2nd gear, 3rd gear, 4th gear, and 5th gear.
3rd gear is bad,must put new gear in or replace transmission.
If its automatic your transmission probably slipped,if it standard your gear is probably warn out and it cant grab it.
missing teeth on third gear
A manual (standard) transmission.
If your transmission is manual, you will have to change gear. If it is automatic, you won't.
The transmission. or clutch if it has one.
85W140 Gear oil on a manual transmission.
Depending on the vehicle, many standard transmissions use ATF, not gear oil.