4. Hub Sleeve
The hub sleeve engages the main gears from the hub gear. Depending on the location in which the gear shifts, the hub sleeve can also move to the right and left. The hub gear is like the deliverer of the engagement that lies between the main gear and the hub gear. There are small teeth on the hub gear that will synchronize with the teeth of the synchronizer ring as there is gear shifting in the transmission. But if the hub sleeve were to get damaged or worn out, it would be difficult to shift the transmission.
The manual transmission systems’ main component is the gear, which is made up of the counter gear, reverse gear, 5th gear, 4th gear, 3rd gear, 2nd gear, and 1st gear. Each gear has 2 teeth that are small and big. The function of the smaller teeth is to accept the hub sleeve’s engagement with the synchronizer ring. If these small teeth were to become damaged or worn out, it would be difficult to shift the transmission. And when a gear is shifted, the function of the bigger teeth is to engage the spinning counter gear which sends a transmission to the output shaft. If the big teeth are damaged or worn out, the transmission will make noise.
6. Not Enough Gear Oil
If your transmission is leaking oil or you do not change it periodically, you will have less oil in the gear. Once this happens, there will be damage to your transmission and it will eventually become hard to shift it. There may even be strange noises or poor vehicle performance symptoms too.
Ok, now you already knows the 6 common causes of manual transmission hard to shift. The top 6 causes above are often occur especially on the car with high milaeage. And finally to learn more about how manual transmission works and working principle, see the video below: