Automatic Transmission:
1. Locate the dipstick: The dipstick is usually located on the transmission itself, often with a handle shaped like a gear or a dipstick that's clearly marked "Transmission". It might be near the back of the engine, accessible from the top.
2. Check the fluid level: With the engine running and warmed up (to operating temperature), remove the dipstick, wipe it clean, reinsert it fully, and remove it again to check the level. The dipstick will have markings indicating "ADD," "FULL," and possibly "LOW."
3. Add fluid (if needed): If the fluid is low, locate the transmission fluid filler tube. This is often a separate tube near the dipstick, but sometimes it's the same tube. Consult your owner's manual for the exact location, which might show a picture. It's usually a threaded fitting that you can use a funnel with the appropriate fitting to pour in the recommended type of transmission fluid. Your owner's manual will specify the correct type (e.g., Dexron, Mercon). Do not overfill.
4. Check the level again: After adding fluid, recheck the level with the engine running and warmed up.
Manual Transmission:
Manual transmissions on these trucks generally do not have dipsticks. They are typically filled through a specific fill plug on the side of the transmission case. This is a more involved process.
1. Locate the fill plug: Your owner's manual is crucial here. The fill plug is often a slightly recessed bolt head. It's generally a bit higher than the drain plug.
2. Locate the drain plug: Find the drain plug (usually on the bottom of the transmission). You'll need to drain some of the old fluid to get it to the correct level. Be prepared to catch the old fluid with a drain pan.
3. Drain and refill: Drain the old fluid. Once drained, refill through the fill plug using a funnel and the correct type of gear oil (your owner's manual will specify the correct type and weight). You'll need to add fluid until it starts to come out of the fill hole. Then, replace the fill plug.
Important Considerations for Both Types:
* Consult your owner's manual: This is absolutely the most important step. Your owner's manual will have specific instructions and diagrams for your particular 1977 Chevy truck model.
* Correct fluid type: Using the wrong type of transmission fluid can severely damage your transmission.
* Safety: Work on a level surface, use jack stands if you are working underneath the truck, and wear appropriate safety gear (gloves, eye protection).
* Professional help: If you're uncomfortable performing this task yourself, take your truck to a qualified mechanic. Incorrect fluid levels can lead to transmission failure.
Without knowing the specific model and transmission type of your 1977 Chevy truck, this is the best general advice. Always refer to your owner's manual for precise instructions.
