Here's a general overview. Specific steps and torque specifications may vary slightly depending on your engine (2.4L or 3.0L). Consult a repair manual specific to your 1999 Nissan Altima for detailed instructions and diagrams. A Haynes or Chilton manual is a good investment for DIY car repairs.
Tools You'll Likely Need:
* Socket wrench set: Including metric sizes.
* Ratchet: A good quality ratchet will make the job easier.
* Wrench set: For various bolts and possibly the tensioner.
* Jack and jack stands: Essential for safe working conditions.
* Wheel chocks: To secure the vehicle.
* Serpentine belt: Purchase the correct replacement belt for your Altima's engine.
* Idler pulley tensioner: Purchase a replacement tensioner.
* Torque wrench: To properly tighten bolts to manufacturer specifications.
* Gloves: Protect your hands.
* Safety Glasses: Protect your eyes.
* Possibly a pulley holding tool: To prevent the pulley from spinning while you loosen or tighten the bolt.
General Steps (Consult your repair manual for specifics):
1. Safety First: Park on a level surface, engage the parking brake, and use wheel chocks. Raise the vehicle using a jack and securely support it with jack stands. Never work under a vehicle supported only by a jack.
2. Locate the Serpentine Belt and Idler Pulley Tensioner: The serpentine belt runs around the crankshaft pulley, water pump, alternator, power steering pump, and other accessories. The idler pulley tensioner is a component that allows you to loosen the belt to remove or install it.
3. Loosen the Idler Pulley Tensioner: This is usually done by turning a bolt on the tensioner using a wrench or socket. This will release tension on the serpentine belt. Your repair manual will show you the exact location and how to do this. Some tensioners use a pivot bolt, others have a different mechanism.
4. Remove the Serpentine Belt: Once the tension is released, carefully route the belt off of the pulleys. Pay attention to how the belt routes to ensure you reinstall it correctly.
5. Remove the Old Idler Pulley Tensioner: This typically involves removing the bolts that hold the tensioner to the engine block or other mounting point. Again, your repair manual is crucial here, as the specific location and bolt sizes will vary.
6. Install the New Idler Pulley Tensioner: Install the new idler pulley tensioner, ensuring it's properly aligned and seated. Tighten the bolts to the manufacturer's specified torque.
7. Install the New Serpentine Belt: Carefully route the new belt around all the pulleys, following the same path as the old belt. Make sure it sits correctly in all the grooves.
8. Check Belt Tension: Once the belt is on, release the tensioner so it applies pressure to the belt. The belt should have the correct amount of tension; your repair manual will specify how to check this.
9. Lower the Vehicle: Carefully lower the vehicle from the jack stands.
10. Test: Start the engine and check for any squealing or other unusual noises coming from the serpentine belt. Inspect all belts and pulleys for proper operation.
Important Considerations:
* Torque Specifications: Always tighten bolts to the manufacturer's specified torque using a torque wrench. Over-tightening can damage components, while under-tightening can lead to loose parts and failure.
* Repair Manual: A repair manual is absolutely essential for this job. It will provide detailed instructions, diagrams, torque specifications, and other crucial information specific to your 1999 Nissan Altima.
* Safety: Always prioritize safety. Use jack stands, wear safety glasses, and be cautious when working under the vehicle.
This is a general overview. Refer to a repair manual specific to your 1999 Nissan Altima for detailed instructions and diagrams before attempting this repair. If you're unsure about any step, it's best to seek professional help from a qualified mechanic.
