How to Replace the Serpentine Belt on a 2018 GMC Acadia (Drive Belt Guide)
Step-by-step instructions with required tools, belt routing tips, safety checks, and common noise troubleshooting for 2017, 2018, 2019, 2020, 2021, 2022, 2023
How to Replace the Serpentine Belt on a 2018 GMC Acadia (Drive Belt Guide)
Step-by-step instructions with required tools, belt routing tips, safety checks, and common noise troubleshooting for 2017, 2018, 2019, 2020, 2021, 2022, 2023
š§ Acadia - Serpentine Belt Replacement
The serpentine belt (drive belt) runs your alternator, A/C compressor, and other accessories. Replacing it is mostly about safely releasing the belt tensioner, swapping the belt, and confirming the routing is correct on every pulley.
Difficulty Level: Intermediate | Estimated Time: 0.5-1.0 hours
ā ļø Safety & Precautions
- ā ļø Work on a cool engine; belts and pulleys can burn you.
- ā ļø Keep fingers, hair, and clothing away from pulleys.
- ā ļø Key out of the vehicle so nobody can start it.
- ā ļø Do not pry on pulleys with a screwdriver.
- Battery disconnect is not required for this job.
š§ Required Tools
You'll need the following tools for this repair:
- Safety glasses
- Mechanic gloves
- Flashlight
- Serpentine belt tool (specialty)
- 3/8" drive breaker bar
- 15mm socket
- 3/8" drive ratchet
- Trim clip removal tool
š© Required Parts
HowToo sells all the parts you need for this repair:
- Serpentine belt - Qty: 1
š Before You Begin
- Park your Acadia on level ground and set the parking brake.
- Open the hood and use a flashlight to find the belt routing diagram (often on the upper radiator support). If itās missing, take a clear photo of the current belt routing before removal.
- A ābelt tensionerā is a spring-loaded arm that keeps the belt tight. Youāll rotate it to relieve tension.
- A āserpentine belt toolā is a long handled tool made to reach the tensioner in tight spaces.
šØ Step-by-Step Instructions
Follow these steps in order:
Step 1: Get access to the belt area
- Use a flashlight to locate the belt path at the front of the engine.
- If an air inlet duct or cover is blocking access, remove it using a trim clip removal tool (for push-clips) and a 3/8" drive ratchet with the appropriate fastener/socket already on hand.
- Take a photo before you remove anything.
Step 2: Relieve belt tension at the tensioner
- Place a 15mm socket on the belt tensioner pulley bolt (the smooth pulley on the spring-loaded arm), using a 3/8" drive breaker bar or serpentine belt tool (specialty).
- Rotate the tensioner to relieve tension, then hold it in the released position.
- While holding the tensioner, slide the belt off the nearest easy-to-reach pulley (commonly an upper smooth/idler pulley) by hand with mechanic gloves.
- Slowly release the tensioner back to its resting position (do not let it snap back).
Step 3: Remove the old belt
- Pull the belt out from around the remaining pulleys by hand (use mechanic gloves).
- Inspect pulleys by spinning them by hand: they should spin smoothly and quietly with no wobble.
- Inspect the tensioner arm movement by rotating it again with the 15mm socket and breaker bar; it should move smoothly and spring back firmly.
Step 4: Route the new belt correctly
- Compare the old belt to the new belt (same length and rib count).
- Route the new belt following the under-hood belt diagram (or the photo you took).
- Make sure the ribbed side of the belt sits in the grooves of ribbed pulleys, and the smooth side runs on smooth pulleys.
- Leave the belt off one easy-to-reach pulley last (this gives you slack for the final install).
Step 5: Apply tension and seat the belt
- Rotate the tensioner again using the 15mm socket and 3/8" drive breaker bar (or serpentine belt tool (specialty)).
- Slip the belt fully onto the last pulley by hand (use mechanic gloves).
- Slowly release the tensioner to tension the belt.
- Visually check every pulley: the belt must be centered and fully seated in all grooves.
- If one rib is off, re-route now.
Step 6: Reinstall any covers or ducts
- Reinstall any air ducting/covers you removed using a trim clip removal tool (clips) and a 3/8" drive ratchet.
ā After Repair
- Start the engine and let it idle for 30-60 seconds while you watch the belt track.
- Listen for squeal, chirping, or slapping sounds. If you hear any, shut the engine off and re-check belt seating and routing.
- Turn on the A/C for a moment; confirm no belt noise changes dramatically.
- Recheck the belt position once more after the first short drive.
š° DIY vs Shop Cost
Shop Cost: $150-$260 (parts + labor)
DIY Cost: $35-$70 (parts only)
You Save: $80-$200 by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.5-1.0 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.


















