Can You Use ATF in a Manual Transmission?

Automatic Transmission Fluid Might Work for Your Manual Transmission

Question: Ford Ranger Manual Transmission - Can I Use ATF?

I own a 1991 Ford Ranger, and it is my first stick shift vehicle. Can I use automatic transmission fluid in a manual transmission? If so, would Dextron-III, Ford Mercon multipurpose ATF be alright to use?

Answer: Transmission Fluid for Manual Transmissions

While automatic transmissions require automatic transmission fluid, manual transmissions use a variety of fluids.

Check your owner's manual to see what fluid is recommended. It may use regular motor oil, heavyweight hypoid gear oil or automatic transmission fluid. If you don't have an owner's manual, check a local certified repair shop or the dealer's service center to find the right fluid for your vehicle.

The purpose of the transmission fluid in a manual transmission is to lubricate the moving parts in the transmission.  While automatic transmissions generate more heat and break down the automatic transmission fluid, manual transmissions do not. Automatic transmission fluid acts as a coolant in an automatic transmission and translates the power of the engine to the transmission.

However, over time manual transmission fluid picks up metal flakes and debris from the transmission components. Eventually, it will need replacing. You should follow the recommended replacement schedule for your vehicle. The transmission fluid level should also be checked periodically.

Otherwise, you might not know it has gotten low until it is too late and your transmission is making alarming noises.

Recommended Transmission Fluid for Ford Rangers

Your question brings up a good example of the variety of transmission fluid recommended by the manufacturer. Here is the fluid type and capacities recommended by Ford.

The Ford Ranger used either the Mazda M5OD 5-speed Transmission or the 5-speed Mitsubishi Transmission.

Manual Transmission Fluid Types And Capacity

TransmissionFluid TypeCapacity
5-speed Mitsubishi*
Note: Used in some Ranger & Bronco II and identified by drain plug located in middle of pan
80W EP5.6 pints
Mazda M5OD Transmission.Mercon(R) Automatic Transmission Fluid or equivalent.5.6 pints
ZFM5OD-HD 5-speed TransmissionMercon(R) Automatic Transmission Fluid or equivalent.
Note: Synthetic Mercon (E6AZ-19582-B) may be used in extreme operating conditions to improve bearing life; extensive idling at less than -25 degrees F, severe duty at greater than 100 degrees F. If transmission lubricant is suspected of overheating.
6.8 pints
Warner Four-Speed Transmission Without Extension - 4x4.80W EP7 pints

As you see, there is quite a variety of fluid recommended. Check your owner's manual. If you can't locate one for your vehicle, which might be common for older models or used vehicles, consult with a local Ford-certified repair shop or the dealer's service center. They will be able to give you a recommendation.

How to Check Your Automatic Transmission Fluid Level: A video showing you how to check your fluid level if you have an automatic transmission.

How to Check the Automatic Transmission Fluid Level in a Ford Pickup: If you have a pickup with an automatic transmission, here's how to check it.