Manual Transmission Facts

Manual transmission repair diagrams

A manual transmission can be quite sturdy if operated and maintained properly. This is one component that should last the life of the vehicle without any major breakdowns.

Although modern units with cases made from aluminum are not as strong as the “Rock Crushers” that Chevy put out in the late 60′s they are less then half the weight.

This of course increases fuel economy by reducing weight. But also can reduce the tolerance of being run low on fluid. Case damage on a newer trans will usually call for replacement.

These modern day manual units are designed so the internal working parts will operate in a bath of oil circulated by the motion of the gears and the shafts inside.

Some of these units will use oil slinging technology to through oil were it is needed most. This is similar to splash lubrication used in modern automotive engines.

Some manufacturers use a pump and tubes to circulate oil to critical areas that require more lubrication than the natural circulation would offer.

Manual transmission fluids

Providing good internal lubrication is the key to the longevity of the transmissions life. If the amount of lubrication falls below the minimum levels or if the trans fluid becomes too dirty major problems can result.

Note that most car makers do not offer fluid filtering on a manual trans. But instead may have magnets inside to pull metal shavings out of the fluid. These magnets can aid in trouble diagnosis as they will hold the worn material for inspection. I have more information about the insides and how to learn manual transmissions.

Transaxle Manual Shift

Different car manufacturers will often use different transmission fluids in their units. The internal assembly procedure and tolerances are specifically designed to operate with this specific fluid installed from the factory.

Installing the wrong kind of manual transmission lubricant can affect the overall protection of the internal moving parts.

An example would be if the transaxle were designed to use automatic transmission fluid. If 75W90 gear oil is installed in replacement of the transmission fluid, inadequate lubrication is most often the result. Read more