Changing main bearings with the engine still nestled in the car is a challenging but achievable task for experienced DIY mechanics. It requires patience, precision, and a thorough understanding of your engine’s anatomy. This guide will walk you through the process of how to change main bearings with engine in car, providing detailed steps and essential tips to ensure a successful outcome. We’ll cover everything from preparation and tools to the actual replacement procedure, helping you save money on costly professional repairs. This process, while demanding, can significantly extend the life of your engine.
Preparing for Main Bearing Replacement (Engine In-Situ)
Before diving into the greasy depths of your engine, proper preparation is key. This involves gathering the necessary tools, understanding your engine’s specifications, and creating a clean and organized workspace.
- Gather your tools: You’ll need a socket set, torque wrench, engine support bar, oil pan gasket, new main bearings, plastigauge, and various hand tools.
- Consult your engine’s manual: Torque specifications and bearing sizes are crucial for a successful replacement.
- Clean your workspace: A clean environment minimizes the risk of contamination.
Having the right tools and information readily available will streamline the process and reduce the chances of errors.
Pro Tip: Take pictures throughout the process. This will help you remember the order of disassembly and reassembly.
Step-by-Step Guide: Replacing Main Bearings In-Car
This section outlines the procedure for replacing main bearings with the engine still in the vehicle. Remember to work carefully and methodically, paying close attention to detail.
- Support the Engine: Use an engine support bar to safely suspend the engine from above.
- Drain the Oil: Remove the oil pan drain plug and allow all the oil to drain completely.
- Remove the Oil Pan: Carefully detach the oil pan, taking care not to damage the gasket surface.
- Remove the Oil Pump: Disconnect and remove the oil pump.
- Remove Main Bearing Caps: Loosen and remove the main bearing caps one at a time. Keep track of their orientation.
- Remove Old Bearings: Gently push out the old bearing shells from the block and the bearing caps.
- Install New Bearings: Install the new bearing shells into the block and bearing caps. Ensure they are properly seated.
- Check Clearance with Plastigauge: Place a small piece of plastigauge on the bearing surface and reinstall the bearing cap. Torque to specification and then remove the cap to check the plastigauge width. Compare to the plastigauge packaging to ensure proper clearance.
- Reinstall Main Bearing Caps: Reinstall the main bearing caps, torquing them to the manufacturer’s specifications.
- Reinstall Oil Pump: Reattach the oil pump.
- Install New Oil Pan Gasket and Oil Pan: Install a new oil pan gasket and reinstall the oil pan. Torque the bolts to specification.
- Refill with Oil: Refill the engine with the correct type and amount of oil.
Important Considerations
- Torque Specifications: Always adhere to the manufacturer’s torque specifications for all bolts.
- Bearing Orientation: Ensure the bearing shells are installed with the correct orientation.
- Cleanliness: Maintain a clean working environment to prevent contamination.
Interesting Fact: Main bearings support the crankshaft, allowing it to rotate smoothly. Worn bearings can lead to engine knocking and reduced performance.
