What is manual transmission fluid, and why does it need to be changed?

airdrie transmission

Manual transmissions have been jokingly called a “millennial anti-theft device” because of how rare they have become today, and how few people know how to drive them. That being said, there are still a lot of manuals on the road, and – just like an automatic transmission – they need maintenance too!

Manual transmissions are filled with fluid in order to lubricate the gears and other internal moving parts. Like any other automotive lubricant, this fluid eventually breaks down and loses its ability to protect your transmission. The fluid also contains additives that break down over time, like corrosion inhibitors, and anti-foaming agents. 

A manual transmission is fairly simple, and can provide decades of reliable service with only minor maintenance. Most of the internal transmission failures that we see (including failed or noisy bearings; worn gears that whine; and worn or grinding synchronizers) can be completely or partially attributed to lubrication-related issues. Regularly replacing your manual transmission fluid provides relatively cheap insurance against most major transmission problems.

How often should manual transmission fluid be changed?

Most car manufacturers recommend replacing the fluid in their manual transmissions around every 100,000 km. Recommendations vary from vehicle to vehicle, so we suggest checking your owner’s manual for your car’s specific requirements. We can also look up this information for you!

Replacing manual transmission fluid in Airdrie:

airdrie clutch repair

When replacing fluid in a manual transmission, being careful to use just the right fluid is very important. This is because the fluid must be just “slippery” enough to lubricate properly, but not too much – or else your synchronizers will not work properly. Synchronizers (or “synchros”) are like little clutches that speed up or slow down the next gear as you shift, helping you complete the gear change without grinding. A fluid with the wrong friction coefficient will cause the synchros to slip too much; wearing them out quickly. 

Because we’re very picky about fluids, you can be confident that our caring journeyman technicians will select just the right fluid for your vehicle, in order to protect your transmission, and your warranty. All of the fluids we stock are genuine OEM and approved lubricants. 

The process of replacing manual transmission fluid is fairly simple: the fluid is usually drained through a drain plug on the bottom of the unit, and then refilled through a fill plug. Some transmissions contain screens or magnets that need to be cleaned during this process. Many transmissions’ fill plugs are in very hard-to-reach places, so we use a special pump to push the new fluid in. The whole procedure usually takes half an hour or less.

If you would like us to provide an estimate for a manual transmission service, or even if you just have a question, please get in touch!