🔧 CX-9 - Engine Mount Replacement

On your CX-9, the engine and transmission are held in place by multiple mounts (typically a right-side engine mount, a left-side transmission mount, and a rear “torque” mount). Replacing worn mounts reduces vibration, clunks on takeoff, and driveline movement—but the engine must be safely supported before any mount bolts come out.

Difficulty Level: Advanced | Estimated Time: 2-5 hours (depends which mount)

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⚠️ Safety & Precautions

• ⚠️ Support the engine before removing any mount bolts—never let the engine “hang” by hoses/wiring.
• ⚠️ Do not jack directly on the oil pan—use a wood block to spread the load.
• ⚠️ Let the turbo/exhaust cool completely before working near the right side of the engine.
• ⚠️ Use jack stands on solid points; never rely on a floor jack alone.
• ⚠️ If you remove the battery/battery tray (common for the left mount), disconnect the negative terminal first.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Mechanic gloves
• Wheel chocks
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wood block (2x6 or 2x8, 12-18 in long)
• Engine support bar (specialty)
• 10mm socket
• 12mm socket
• 14mm socket
• 17mm socket
• 19mm socket
• 3/8 in ratchet
• 1/2 in breaker bar
• Socket extensions (3 in and 6 in)
• Torque wrench (10-200 ft-lbs range)
• Trim clip removal tool
• Flathead screwdriver
• Flashlight
• Paint marker

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Right-side engine mount - Qty: 1 (if replacing)
• Left-side transmission mount - Qty: 1 (if replacing)
• Rear torque mount - Qty: 1 (if replacing)
• Engine mount hardware kit - Qty: 1 (if required)

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📋 Before You Begin

• Park on level ground, set the parking brake, and chock the rear wheels.
• Open the hood and remove any loose items around the engine bay.
• If you’ll remove the battery or battery tray: use a 10mm socket to disconnect the negative battery terminal first and isolate it so it can’t spring back.
• Plan to replace one mount at a time so the drivetrain stays aligned.
• Tip: Take “before” photos for hose/clip routing.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Confirm which mount(s) you’re replacing

• Right-side engine mount = passenger side of the engine bay (often near coolant reservoir area).
• Left-side transmission mount = driver side (often under/near the battery tray area).
• Rear torque mount = low, toward the rear of the engine/trans, accessed from underneath.
• Use a flashlight to locate the mount and the bracket bolts before loosening anything.

Step 2: Raise the CX-9 and remove lower covers (for rear mount access)

• Use a floor jack (rated 3-ton minimum) at the front center jacking point and set the vehicle on jack stands (rated 3-ton minimum).
• Use a trim clip removal tool and 10mm socket to remove the lower splash shields/under-covers as needed.

Step 3: Support the engine safely

• Best method: Install an engine support bar (specialty) across the strut towers and tension it to hold the engine slightly.
• Alternate method: Place a wood block (2x6 or 2x8) on the floor jack (rated 3-ton minimum) and gently contact the bottom of the engine (use the wood to spread the load).
• Raise only enough to “take the weight” off the mount—do not lift the vehicle off the stands.
• Tip: Watch hoses while lifting slightly.

Step 4: Replace the right-side engine mount (if applicable)

• Use a 10mm socket and trim clip removal tool to move/remove any covers or ducts blocking access.
• If the coolant reservoir blocks access, use a 10mm socket to unbolt it and set it aside without disconnecting hoses (support it so hoses aren’t strained).
• Use a paint marker to mark the mount position relative to the bracket (helps alignment on reassembly).
• Use a 14mm socket / 17mm socket (varies by fastener) with a ratchet and extensions to remove the mount fasteners.
• Use the floor jack or engine support bar to slightly raise/lower the engine until the mount comes out without forcing it.
• Install the new mount by hand-starting all bolts/nuts first.
• Use a torque wrench to tighten fasteners: Torque to Mazda factory specification.

Step 5: Replace the left-side transmission mount (if applicable)

• If equipped, disconnect the battery negative cable using a 10mm socket, then remove the battery hold-down with a 10mm socket and lift the battery out.
• Use a 10mm socket / 12mm socket to remove the battery tray/air ducting as needed for access.
• Mark mount alignment with a paint marker.
• Use a 14mm socket / 17mm socket with a breaker bar if needed to loosen mount-to-body and mount-to-bracket fasteners.
• Adjust engine height slightly with the engine support bar or floor jack so bolts come out smoothly (no binding).
• Install the new mount, hand-start all fasteners, then tighten with a torque wrench: Torque to Mazda factory specification.
• Reinstall the battery tray and battery using a 10mm socket, then reconnect the negative terminal last using a 10mm socket.

Step 6: Replace the rear torque mount (if applicable)

• From underneath, locate the rear torque mount at the rear of the engine/trans assembly.
• Use a 14mm socket / 17mm socket with a ratchet and extensions to remove the mount bolts.
• If bolts are tight, use a 1/2 in breaker bar carefully (steady pressure, don’t round the bolt).
• Lower or raise the drivetrain slightly using the engine support bar or floor jack to remove/install the mount without prying.
• Install the new torque mount and hand-start bolts.
• Tighten using a torque wrench: Torque to Mazda factory specification.

Step 7: Reinstall under-covers and final check

• Reinstall all splash shields using a 10mm socket and trim clip removal tool.
• Remove the engine support bar or lower the floor jack slowly so the drivetrain settles naturally.
• Do a quick visual check with a flashlight for pinched wiring, stretched hoses, or tools left behind.

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✅ After Repair

• Start the engine and let it idle; listen for abnormal knocking and watch for excessive movement.
• With your foot on the brake, shift from Park to Reverse to Drive and feel for clunks (normal to feel slightly different with new mounts).
• Take a short test drive and re-check for any new vibrations or warning lights.
• Re-check mount fasteners for tightness after a short drive: Verify tightened to Mazda factory specification.

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💰 DIY vs Shop Cost

Shop Cost: $600-$1,400 (parts + labor, depends how many mounts)

DIY Cost: $120-$450 (parts only, depends which mount)

You Save: $480-$950 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2-5 hours.

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🎯 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.