Here are some of the reasons why you should not use ATF in a manual transmission:
- ATF is thinner than manual transmission fluid (MTF), and it does not provide the same level of protection for the gears and bearings in a manual transmission. ATF can cause the gears to wear out prematurely.
- ATF does not contain the same additives as MTF, which are necessary to prevent corrosion and foaming in a manual transmission.
- ATF can cause the seals in a manual transmission to swell and leak.
- ATF can cause the shift forks in a manual transmission to become sticky, which can make shifting difficult.
If you accidentally put ATF in a manual transmission, you should drain it immediately and replace it with the proper MTF.
