How to Replace the Serpentine Belt on a 2020 Mazda CX-5 (Drive Belt Guide)
Step-by-step instructions with required tools, belt routing tips, safety checks, and post-install inspection for 2013, 2014, 2015, 2016
How to Replace the Serpentine Belt on a 2020 Mazda CX-5 (Drive Belt Guide)
Step-by-step instructions with required tools, belt routing tips, safety checks, and post-install inspection for 2013, 2014, 2015, 2016
š§ CX-5 - Serpentine Belt Replacement
The serpentine belt (also called the drive belt) turns accessories like the alternator and A/C compressor. Replacing it on your CX-5 means releasing the spring-loaded belt tensioner, swapping the belt, then verifying the belt is seated correctly on every pulley.
Difficulty Level: Intermediate | Estimated Time: 0.5-1.0 hours
ā ļø Safety & Precautions
- Work on a cool engine; keep hands away from hot parts.
- Key off and keep the key fob away from the vehicle so the engine canāt be started accidentally.
- Do not put fingers between the belt and pulleys while releasing tension.
- The belt tensioner is a spring-loaded arm/pulley that keeps the belt tight; it can snap back quickly.
- Battery disconnect is not required for this job.
š§ Required Tools
You'll need the following tools for this repair:
- 14mm socket
- 3/8" drive ratchet
- 3/8" drive breaker bar (18"-24")
- 3/8" drive extension set (3" and 6")
- Trim clip tool
- Flashlight
- Mechanic gloves
- Safety glasses
š© Required Parts
HowToo sells all the parts you need for this repair:
- Serpentine belt (engine drive belt) - Qty: 1
š Before You Begin
- Park on level ground and set the parking brake.
- Open the hood and remove the plastic engine cover (it pulls upward).
- Find the belt routing diagram (often on a label under the hood). If itās missing, take a clear photo of the current belt routing before removal.
- Photo firstārouting mistakes are common.
šØ Step-by-Step Instructions
Follow these steps in order:
Step 1: Confirm belt routing and pulley layout
- Use a flashlight to locate all pulleys the belt touches (smooth pulleys ride on the beltās smooth side; grooved pulleys ride on the ribbed side).
- Use your phone to take a routing photo, even if you have the under-hood diagram.
Step 2: Relieve belt tension (move the tensioner)
- Place a 14mm socket with a 3/8" breaker bar (18"-24") onto the belt tensionerās hex.
- Pull the breaker bar smoothly to rotate the tensioner and release tension (you will feel strong spring resistance).
- While holding the tensioner rotated, slide the belt off one easy-to-reach pulley (usually a smooth idler/tensioner pulley) using your free hand.
- Slowly let the tensioner return to its resting position (do not let it snap back).
Step 3: Remove the old belt
- Use your hands and a flashlight to walk the belt off the remaining pulleys.
- Compare the old and new belt side-by-side: same length, same rib count, same width.
Step 4: Install the new belt (route it correctly)
- Route the new belt following the under-hood diagram (or your photo).
- Start by wrapping the belt fully around the crankshaft pulley first, then route around the other grooved pulleys.
- Leave the easiest pulley for last (typically a smooth idler/tensioner pulley) so you have slack for the final slip-on.
- Use a flashlight to confirm every belt rib is seated in every pulley groove (no rib hanging off).
Step 5: Apply tension and seat the belt
- Put the 14mm socket and breaker bar back on the tensioner hex and rotate it to create slack.
- Slip the belt onto the last pulley, then slowly release the tensioner.
- Use a flashlight to re-check alignment on all pulleys from above.
- If it looks āone rib off,ā fix it now.
Step 6: Reinstall covers/clips you removed
- Reinstall the engine cover by pressing it straight down onto its grommets.
- If you removed any plastic clips, reinstall them using the trim clip tool.
ā After Repair
- Start the engine and let it idle for 30-60 seconds while you watch the belt track (stand clear of moving parts).
- Listen for squeal, chirping, or slapping noises; shut off immediately if you hear abnormal noise.
- Turn A/C on and off once; re-check belt tracking.
- After a short drive, pop the hood and do a quick visual re-check of belt alignment.
š° DIY vs Shop Cost
Shop Cost: ā¹3,000-ā¹7,000 (parts + labor)
DIY Cost: ā¹1,500-ā¹3,500 (parts only)
You Save: ā¹1,500-ā¹3,500 by doing it yourself!
Shop labor rates vary but typically run ā¹800-ā¹1,500/hour. This repair takes a shop approximately 0.5-1.0 hours.
šÆ Ready to get started?
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