Crucially, this is a somewhat involved job, especially for an older car. If you're not comfortable working on cars, take it to a mechanic. Improper fluid changes can severely damage your transmission.
General Precautions for Both Types:
* Safety First: Use jack stands, never rely solely on a jack. Wear safety glasses and gloves. Work in a well-ventilated area.
* Fluid Type: Use the correct transmission fluid specified for your car's transmission. This information should be in your owner's manual or can often be found online through forums dedicated to classic Pontiacs. Using the wrong fluid can damage your transmission.
* Disposal: Dispose of used transmission fluid properly. Take it to an auto parts store or recycling center that accepts used motor oil.
* Torque Specifications: Consult a repair manual for the correct torque specifications for all bolts and nuts. Over-tightening can cause damage.
Automatic Transmission Fluid Change:
This is more complex and involves several steps. A complete drain and refill isn't as effective as a flush, which requires specialized equipment. Here's a simplified drain and fill:
1. Locate the Transmission Pan: This is usually located underneath the transmission.
2. Prepare for Drainage: Place a drain pan under the transmission pan.
3. Drain the Fluid: Carefully remove the transmission pan drain plug. Let the fluid drain completely.
4. Remove the Transmission Pan: Remove the transmission pan bolts. Be careful; there may be some fluid still in the pan.
5. Clean the Pan and Filter (if accessible): Clean the transmission pan and replace the filter (if your transmission has one and it's accessible – some are internal and require a more significant job).
6. Reinstall the Pan: Reinstall the transmission pan, ensuring the gasket is properly seated. Tighten the bolts evenly.
7. Refill the Transmission: Locate the transmission fluid filler tube (often a dipstick tube). Using a funnel, add the correct type and amount of transmission fluid. The amount needed will depend on your transmission type and is often listed in a repair manual.
8. Check the Fluid Level: Check the fluid level using the dipstick. Add more fluid if needed to reach the proper level. The engine should be running when you check the level on an automatic. This may require running the car and checking periodically, as it will need time to reach operating temperature.
9. Road Test: Take the car for a short test drive. Check for leaks and unusual noises.
Manual Transmission Fluid Change:
This is generally simpler.
1. Locate the Drain Plug and Filler Plug: These are usually located on the transmission case.
2. Prepare for Drainage: Place a drain pan under the drain plug.
3. Drain the Fluid: Remove the drain plug and let the fluid drain completely.
4. Refill the Transmission: Once the fluid has drained, replace the drain plug. Then locate the filler plug. Add the correct type and amount of manual transmission fluid through the filler plug until it starts to overflow.
5. Check Fluid Level (If Applicable): Some manual transmissions have a dipstick or other method to check the fluid level; consult your repair manual.
Finding Information:
* Repair Manual: A repair manual specific to your 1972 Pontiac LeMans is invaluable. It will provide detailed instructions, torque specifications, and diagrams. Haynes and Chilton manuals are popular choices.
* Online Forums: Online forums dedicated to classic Pontiacs (e.g., Pontiac enthusiast forums) are excellent resources for advice and tips from experienced owners.
Again, if you're not comfortable performing this task, take your car to a qualified mechanic. Transmission problems can be very expensive to fix. It's much cheaper to pay a professional than to risk damaging your transmission.
