Here's what you'll generally need to consider:
1. Specialized Tools:
* Timing Chain Tool Set: This is absolutely essential. It will include tools to hold the crankshaft and camshafts in the correct position during the process. Improper alignment will lead to catastrophic engine damage.
* Engine Hoist: Unless you're incredibly strong and have an extremely sturdy engine stand, you'll need an engine hoist to lift and support the engine. This might be necessary for easier access to certain components.
* Torque Wrench: Accurate torque specifications are critical for proper assembly.
* Sockets, Wrenches, and other hand tools: A complete set of metric tools will be necessary.
* Shop Manual: A factory service manual for a 1998 Nissan Altima is indispensable. It will provide detailed instructions, torque specifications, and diagrams. This is the single most important tool you will need.
2. Preliminary Steps:
* Disconnect the Battery: This is a crucial safety precaution.
* Drain Engine Fluids: Drain the engine oil, coolant, and possibly power steering fluid.
* Remove Accessory Components: You'll likely need to remove various components to access the timing chain, such as the serpentine belt, pulleys, various covers, and possibly even the front of the engine.
3. Timing Chain Replacement:
* Locate and Remove the Timing Chain Cover: Access to the timing chain requires careful removal of the timing chain cover.
* Identify Chain Guides and Tensioners: These components need to be inspected for wear and replaced as needed.
* Remove the Old Timing Chain: This involves carefully releasing the chain from the sprockets on the crankshaft and camshafts.
* Install the New Timing Chain: This is the reverse of the removal process, but *crucially important* is ensuring the sprockets and chain are properly aligned using your timing chain tool kit. Misalignment will cause valve-to-piston contact and immediate, irrecoverable engine damage.
* Install New Guides and Tensioners: Replace these components with new parts.
* Reinstall the Timing Chain Cover: This must be done carefully and securely.
* Reinstall Removed Components: Reassemble all components removed earlier, ensuring proper torque specifications are met.
4. Post-Replacement Checks:
* Refill Fluids: Refill engine oil, coolant, and other fluids.
* Start the Engine: Carefully start the engine and listen for any unusual noises.
* Check for Leaks: Inspect for leaks around the timing chain cover and other components.
Again, this is a very complex and potentially damaging repair. If you are not a highly experienced mechanic with the proper tools and knowledge, you should take your vehicle to a qualified professional. The cost of repairing engine damage caused by an improperly installed timing chain far outweighs the cost of having a mechanic do the job correctly. Attempting this repair yourself could easily cost you thousands of dollars in engine damage.
