Replacement of the transmission mount (also called front engine mount) on the 2016-2021 Honda Civic 1.5L Turbo to eliminate vibration and secure the transmission assembly.

Warnings

Tools required

Parts

• Transmission mount assembly × 1 — Use OEM Honda part number 50805-TBA-A81 or equivalent

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely if recently driven
3. Raise front of vehicle and secure on jack stands rated for vehicle weight
4. Remove engine undertray/splash shield if equipped to access mount area
5. Visually inspect transmission mount location from below - mount is located at front of transmission, closest to radiator

Procedure

1. 1

   Support the transmission assembly
   Position a transmission jack or floor jack with wood block under the transmission oil pan. Raise jack until it just contacts the transmission but does not lift it. Alternatively, install an engine support bar across the top of the engine bay to support the powertrain from above. The goal is to support the transmission weight without putting strain on other mounts.
   ⚠️Ensure jack is stable and will not slip. Use a wide piece of wood between jack and oil pan to distribute load and prevent pan damage.
2. 2

   Remove transmission mount upper bolts
   From above the engine bay, locate the transmission mount bracket bolted to the transmission. Remove the bolts securing the mount bracket to the transmission housing. These are typically 2-3 bolts accessible from the top. Note the bolt locations and any washers or spacers for reinstallation.
   Torque spec

   Transmission Mount Bolts65 Nm (48 lb-ft)
3. 3

   Remove transmission mount lower through-bolt
   From underneath the vehicle, locate the large through-bolt that passes horizontally through the transmission mount and connects to the subframe/crossmember. Remove the nut from this through-bolt first, then drive the bolt out using a brass drift or punch. This bolt may be tight due to weight compression.
   ⚠As you remove the through-bolt, ensure the transmission jack is supporting the weight. The transmission may shift slightly when bolt is removed.
   Torque spec

   Transmission Mount Bolts65 Nm (48 lb-ft)
4. 4

   Remove mount from vehicle
   With all fasteners removed, carefully work the transmission mount assembly out of its position. You may need to slightly raise or lower the transmission jack to relieve binding. The mount will separate from both the transmission bracket above and the subframe mounting point below.
5. 5

   Inspect mounting surfaces and hardware
   Clean the transmission mounting surface and subframe mounting points with a wire brush. Inspect the mounting bolt holes in the transmission housing for damage or stripped threads. Check subframe bracket for cracks or deformation. Replace any damaged hardware. Compare old mount to new mount to verify correct replacement part.
6. 6

   Position new transmission mount
   Align the new transmission mount assembly into position. The mount should fit between the transmission bracket location above and the subframe mounting point below. Use the transmission jack to adjust transmission height as needed to align all mounting points. The mount orientation is critical - ensure the rubber isolator is positioned correctly per factory orientation.
   ℹ️The mount has a specific orientation and will only fit correctly one way. Do not force it.
7. 7

   Install mount through-bolt
   Insert the through-bolt that connects the mount to the subframe. Install the nut on the end of the through-bolt but do not fully tighten yet. Thread the nut on several turns to hold the mount in place. Ensure bolt passes through all mounting points correctly.
8. 8

   Install upper transmission mount bolts
   From above, install the bolts that secure the mount bracket to the transmission housing. Hand-thread all bolts first to ensure proper alignment, then tighten progressively in a cross pattern to the specified torque value. Use a torque wrench for final tightening.
   Torque spec

   Transmission Mount Bolts65 Nm (48 lb-ft)
9. 9

   Torque lower through-bolt
   With the upper bolts secured, torque the lower through-bolt nut to specification. This large fastener is critical for mount retention and should be torqued carefully. Hold the bolt head while torquing the nut if necessary to prevent bolt rotation.
   Torque spec

   Transmission Mount Bolts65 Nm (48 lb-ft)
10. 10

    Remove transmission support
    Carefully lower and remove the transmission jack or engine support bar. Allow the transmission weight to settle onto the new mount. Verify there is no unusual sagging or misalignment of the powertrain.

Reassembly

1. Reinstall engine undertray/splash shield with all clips and fasteners
2. Lower vehicle from jack stands
3. Remove wheel chocks and release parking brake

Verification

• Start engine and verify no abnormal vibration or movement of transmission assembly
• With engine running, shift through all transmission gears (P-R-N-D) and verify smooth operation without excessive movement
• Test drive vehicle and listen for any clunking sounds during acceleration or deceleration that would indicate improper mount installation
• After test drive, recheck all transmission mount bolt torque values to ensure nothing has loosened
• Visually inspect mount from below to verify proper seating and no contact with surrounding components

More procedures for this vehicle