The manual transmission fill plug on a 1989 Ford Bronco II is located on the driver's side of the transmission, near the top. It is a 17mm hex head plug.
Here is a more detailed guide to finding the fill plug:
1. Park your Bronco II on level ground and turn off the engine.
2. Open the hood and locate the transmission. It is located at the rear of the engine, behind the transfer case.
3. Look on the driver's side of the transmission for the fill plug. It is a 17mm hex head plug located near the top of the transmission.
4. Once you have found the fill plug, you can remove it using a 17mm wrench.
5. Be careful not to lose the gasket when you remove the plug.
6. Add the recommended amount of manual transmission fluid to the transmission. The recommended amount of fluid is listed in the owner's manual.
7. Replace the fill plug and tighten it securely.
8. Close the hood and start the engine.
9. Check for leaks around the fill plug. If there are any leaks, tighten the plug securely until the leaks stop.
