The manual transmission system is pretty simple in comparison to its automatic cousin. Their gears are located along parallel shafts inside the transmission housing. Power flows when gears are meshed. During gear changes, or when the car is stationary and the engine is idling, a clutch is used to interrupt the flow of power from the engine to the transmission. However, if you are experiencing issues the symptoms are similar to the automatic, and include: slipping, hesitation, bucking, grinding gears and difficulty shifting. Unlike the automatic however, where you actually have to flush the fluids with a machine for preventative maintenance. The manual requires a simple, in comparison, drain and fill of the transmission fluid.
Most manufacturers recommend that manual transmission fluid be changed every 30,000 to 60,000 miles. Under heavy-duty use, such as towing or stop-and-go traffic, some manufacturers suggest changing transmission fluid every 15,000 miles. This is because the transmission fluid provides lubrication to gears, bearings, shafts, and other internal components. Heat, pressure and friction can slowly breakdown the additives in the manual transmission fluid and contamination occurs over time as the synchronizers, bearings and gears in the transmission wear out. The resulting metal particles then float around in the lubricant. And we all know that oil with microscopic particles of metal in it does not lubricate as well as clean oil. So if these contaminants are not drained out, they will shorten the life of your transmission.
Checking the transmission fluid in a manual transmission can be difficult. A few thoughtful manufacturers have included a dipstick, but that’s the exception rather than the rule. If you own a car with a manual transmission, we suggest that you ask your mechanic to check the fluid level when your car is up on the lift during an oil change. It takes just a minute.
Manual transmissions use a variety of oils and are often referred to as gear oil: regular motor oil, heavyweight hypoid gear oil or even automatic transmission fluid in some cases. Your owner’s manual will tell you what your transmission calls for. However, the only time you should have to add oil to a manual transmission or transaxle is if the transmission is leaking oil. If you see any grease or wetness around the tail-shaft or driveshaft seals, the oil level in the transmission or transaxle should be checked because it may be low. WARNING: Allowing the transmission or transaxle to run too low on lubricant can ruin it.
Some simple tips to help improve the life span of your transmission include:
- Drain and refill transmission fluid on a regular basis, especially if you do a lot of towing.
- Avoid riding the clutch – a simple rule of thumb is your foot should be all the way down or all the way off.
- Avoid jack-rabbit starts.