FLUID LEVEL CHECK
- With the truck parked on a level surface, remove the filler plug from the side of the transmission. Be careful not to take out the drain plug at the bottom.
- If lubricant seeps out, there is enough. If not, carefully insert a finger (watch out for sharp threads) and check that the level is up to the edge of the hole.
- Lubricant may be added with a suction gun or squeeze bulb. The correct lubricant is SAE 80W-90 GL-5 Gear Lubricant or SAE 80W GL-5 for cold climates and Dexron II for the 4-speed manual with overdrive.
- Replace the plug.
DRAIN AND REFILL
No intervals are specified for changing transmission lubricant, but it is a good idea on a used vehicle, one that has been worked hard, or if you have driven in deep water. The transmission should be at normal operating temperature.
- Slide a drain pan under the transmission.
- Remove the filler plug from the side of the transmission and the drain plug from the bottom. The 1976 and later Tremec topcover three speed is drained by removing the lower extension housing bolt.
- Wipe the area clean and replace the drain plug.
- Add lubricant with a suction gun or squeeze bulb. The correct lubricant is SAE 80W-90 GL-5 Gear Lubricant, or SAE 80W GL-5 for cold climates.
- When the lubricant level is up to the bottom of the filler hole, replace the plug.