How to Replace the Serpentine Belt on a 2018 Nissan Armada (Step-by-Step Guide)
Tools, parts list, belt routing tips, safety checks, and common tensioner/idler pulley inspection steps for 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024
How to Replace the Serpentine Belt on a 2018 Nissan Armada (Step-by-Step Guide)
Tools, parts list, belt routing tips, safety checks, and common tensioner/idler pulley inspection steps for 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024
š§ Armada - Serpentine Belt Replacement
The serpentine belt drives key accessories like the alternator and A/C. Replacing it means releasing the spring-loaded belt tensioner, swapping the belt, then confirming the belt is routed correctly on every pulley.
Difficulty Level: Intermediate | Estimated Time: 0.5-1.5 hours
ā ļø Safety & Precautions
- ā ļø Work on a cold engine; hot pulleys burn.
- ā ļø Keep fingers, hair, and clothing away from the belt path.
- ā ļø Do not start the engine until the belt is fully seated on every pulley.
- ā ļø If you remove the negative battery cable, you may lose radio clock settings.
š§ Required Tools
You'll need the following tools for this repair:
- 14mm serpentine belt tool
- 14mm combination wrench
- 10mm socket
- 3/8" drive ratchet
- 6" extension (3/8" drive)
- Flat-blade screwdriver
- Flashlight
- Mechanic gloves
- Safety glasses
š© Required Parts
HowToo sells all the parts you need for this repair:
- Serpentine belt - Qty: 1
- Serpentine belt tensioner assembly - Qty: 1 (optional if noisy/weak)
- Idler pulley - Qty: 1 (optional if noisy/rough)
š Before You Begin
- Park on level ground, shift to Park, and set the parking brake.
- Open the hood and let the engine cool fully.
- Find the belt routing diagram (often on a sticker under the hood). If you donāt see one, take a clear photo of the current belt routing before removal.
- If you choose to disconnect the battery: use a 10mm socket to remove the negative terminal first. Torque to 5 Nm (44 in-lbs) when reinstalling.
šØ Step-by-Step Instructions
Follow these steps in order:
Step 1: Get access to the belt area
- Remove the plastic engine cover if it blocks your view: use a 10mm socket and 3/8" drive ratchet where applicable, then lift it off.
- If the intake duct/snorkel is in the way, loosen clamps using a flat-blade screwdriver and reposition it slightly for room.
- Use a flashlight to locate the belt tensioner (the spring-loaded arm with a pulley).
Step 2: Confirm belt routing before removal
- Look for a routing sticker under the hood and compare it to what you see.
- If thereās no sticker, take a photo from above with your phone.
- Photo now saves big confusion later.
Step 3: Release belt tension (tensioner)
- Put a 14mm serpentine belt tool (or 14mm combination wrench) on the tensionerās hex.
- Slowly rotate the tensioner to relieve tension. (Itās spring-loaded, meaning it āpushes backā on you.)
- While holding the tensioner rotated, slide the belt off the easiest-to-reach smooth pulley (often the idler or tensioner pulley) using your free hand.
Step 4: Remove the old belt
- Let the tensioner return slowly to its resting position (do not let it snap back).
- Pull the belt out around the fan shroud area carefully.
- If your Armada has a large engine-driven fan, rotate the fan by hand to help āwalkā the belt out while guiding it with your hands (engine OFF, key away).
Step 5: Quick pulley and tensioner check
- Spin the idler and tensioner pulleys by hand. They should feel smooth and quiet (no grinding, wobble, or rough spots).
- If any pulley feels rough or noisy, plan to replace that pulley/tensioner before installing the new belt.
Step 6: Route the new belt
- Match your routing photo/sticker and route the new belt around the crank pulley first, then the other accessories.
- Make sure the āribbedā side of the belt sits in the grooved pulleys, and the smooth side rides on smooth pulleys.
- Leave one easy pulley for last (an upper smooth pulley is usually easiest) so you can slip it on after releasing tension.
Step 7: Apply tension and seat the belt
- Rotate the tensioner again using the 14mm serpentine belt tool (or 14mm combination wrench).
- Slip the belt onto the last pulley.
- Slowly release the tensioner so it applies tension to the belt.
- Visually check every pulley: the belt ribs must sit centered in the grooves with no overhang.
Step 8: Reinstall anything you removed
- Reinstall the intake duct and tighten clamps using the flat-blade screwdriver.
- Reinstall the engine cover using the 10mm socket and 3/8" drive ratchet.
- If disconnected, reconnect the battery negative terminal using the 10mm socket. Torque to 5 Nm (44 in-lbs).
ā After Repair
- Before starting: do one final belt alignment check on all pulleys with a flashlight.
- Start the engine and watch the belt for 20ā30 seconds. It should run straight with no wobble or chirping.
- Turn A/C on and headlights on to load the belt, then listen for squeal.
- Shut the engine off and re-check belt seating one more time.
š° DIY vs Shop Cost
Shop Cost: $180-$350 (parts + labor)
DIY Cost: $35-$90 (parts only)
You Save: $145-$260 by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.7-1.2 hours.
šÆ Ready to get started?
HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.


















