Assuming you have a 302 V8 with an automatic transmission:
This is a significant job requiring mechanical skills and the right tools. Improperly completing this task can lead to serious engine damage. If you're not comfortable working on your own vehicle, take it to a qualified mechanic.
Here's a general outline of the process, but it's not exhaustive and specific details will vary:
1. Preparation:
* Safety First: Disconnect the negative battery cable. Use jack stands to securely support the truck. Wear safety glasses and gloves.
* Gather Tools: You'll need a torque wrench (crucial!), various sockets and wrenches, a transmission jack (highly recommended), a flywheel/flexplate bolt socket (often a special size), a clutch alignment tool (if replacing the clutch, which you likely are not if the transmission is staying), possibly a harmonic balancer puller, and a shop manual specific to your year and model.
* Drain Transmission Fluid: Before disconnecting anything, drain the transmission fluid.
* Remove Accessories: Disconnect any components attached to the transmission and bellhousing. This might include the starter motor, driveshafts, and possibly the exhaust system (partially).
2. Transmission Removal:
* Disconnect Transmission: Disconnect the linkage and any electrical connectors.
* Support Transmission: Use a transmission jack to support the transmission as you remove the bolts attaching it to the engine. Carefully lower the transmission.
3. Flywheel/Flexplate Removal:
* Inspect the Flexplate: Check for cracks or damage before removal.
* Remove Bolts: Use the correct socket to remove the flexplate bolts. These bolts are often very tight. Use penetrating oil if necessary. Note the order and position of the bolts; they need to go back in the same way.
* Remove Flexplate: Carefully remove the flexplate from the crankshaft. It might be stuck, so use gentle persuasion.
4. Installation:
* Clean Crankshaft: Thoroughly clean the crankshaft mating surface.
* Install New Flexplate: Align the flexplate with the crankshaft and install the bolts, tightening them in a star pattern to ensure even pressure. Use the correct torque specification from your shop manual. This is critical to avoid damage.
* Reinstall Transmission: Carefully align the transmission with the engine and install the bolts.
* Reconnect Everything: Reinstall all components removed in the earlier steps.
* Refill Transmission Fluid: Add the correct amount of transmission fluid.
* Double Check: Verify everything is properly connected and tightened.
If you have a 6-cylinder engine with a manual transmission, it will use a flywheel and the process is similar, but not identical. A 6-cylinder with an automatic transmission will also use a flexplate.
Disclaimer: This is a simplified overview. Consult a comprehensive repair manual specific to your vehicle for detailed instructions, torque specifications, and diagrams. Improperly performing this repair could result in serious damage to your vehicle. If you are unsure about any step, seek professional help.
