transmission

Transmission R&R - Automatic

for 2021 Honda Civic 1.5L I4 Turbo · FWD

Editorial review:Chris Hackleman — Master Technician · 20+ years · Jeff Moore — Master Lexus & Toyota Mechanic · 20+ years

Difficulty

Expert

Time

6.0 h

Tools

Steps

✓Expert-verified. Personally reviewed and approved by OLP's master technicians (Chris Hackleman & Jeff Moore — 20+ years each). Always follow the vehicle's factory service information and torque specs.

This procedure covers the complete removal and reinstallation of the CVT automatic transmission on a 2016-2021 Honda Civic with the 1.5L turbocharged engine.

Warnings

⚠️Transmission weighs approximately 150 lbs. Use proper lifting equipment and never work under a vehicle supported only by a jack.

⚠️CVT fluid will be hot if vehicle was recently operated. Allow adequate cooling time before draining.

⚠CVT transmissions require Honda DW-1 ATF only. Use of incorrect fluid will cause transmission failure.

⚠Do not allow driveshafts to hang unsupported as this can damage CV joints. Support or remove completely.

ℹ️This procedure requires the vehicle to be running for final fluid level verification. Ensure adequate ventilation if working indoors.

Tools required

Floor jack and jack stands rated for vehicle weightEssential

Transmission jack with adapter or transmission support fixtureEssential

Torque wrench (10-100 Nm range)Essential

Socket set (8mm-19mm)Essential

Wrench set (10mm-19mm)Essential

Drain pan (minimum 10 quart capacity)Essential

Pry bar

Wire or mechanics wire for supporting componentsEssential

Funnel with long spout for CVT fluid fillEssential

Scanner tool for CVT fluid temperature monitoringEssential

Ball joint separator or pickle fork

Breaker barEssential

Parts

CVT transmission fluid × 1 — Honda DW-1 ATF
Transmission drain plug crush washer × 1 — Use OEM specification
Driveshaft seals (both sides) × 2 — Use OEM specification
Transmission mount hardware kit × 1 — Use OEM specification if reusing is not recommended

Fluids

Honda DW-1 ATF — 8 qt

Preparation

Position vehicle on level surface and engage parking brake
Disconnect negative battery cable and wait 3 minutes for SRS system to discharge
Raise vehicle and support securely on jack stands at all four corners
Remove front wheels and engine under covers
Remove front splash shields to access lower transmission area
Drain engine coolant partially to allow removal of coolant hoses that may interfere with transmission removal

Procedure

1
Drain CVT fluid
Place drain pan under transmission. Remove the drain plug from the bottom of the transmission pan and allow fluid to drain completely. This will take several minutes. Once drained, reinstall drain plug with new crush washer.
Torque spec
Transmission Drain Plug30 Nm (22 lb-ft)
2
Disconnect electrical connections
Disconnect all electrical connectors from the transmission including: shift solenoid connector, input/output speed sensors, CVT temperature sensor, and transmission range switch. Label connectors for reassembly. Remove any harness brackets attached to transmission.
3
Remove air intake and battery components
Remove the air intake tube and airbox assembly. Remove the battery and battery tray to provide access to upper transmission mounting bolts and cooler lines. Remove the PCM bracket if it interferes with access.
4
Disconnect cooler lines and shift cable
Disconnect the CVT cooler lines from the transmission. Cap or plug lines to prevent contamination. Remove the shift cable from the transmission range switch by releasing the lock tab and sliding cable off. Remove cable bracket from transmission housing.
⚠CVT cooler lines contain residual fluid. Have rags ready to catch spillage.
5
Remove upper transmission mounting bolts
Locate and remove the upper transmission-to-engine mounting bolts. There are typically 4-5 bolts accessible from the top. Note their locations and lengths as they may differ. Remove the upper transmission mount bracket and insulator.
Torque spec
Mounting Bolts26 Nm (19 lb-ft)
6
Remove front subframe and suspension components
From underneath, remove the lower ball joint pinch bolts and separate ball joints from steering knuckles. Remove the stabilizer bar end links. Support the subframe with a jack and remove the subframe mounting bolts. Lower the subframe enough to access driveshafts, or remove completely for better access.
7
Remove driveshafts
Remove the driveshaft retaining nuts from both sides (vehicle must be in gear with parking brake applied to prevent hub rotation). Using a pry bar, carefully pry both driveshafts out of the transmission. Support driveshafts with wire to prevent damage to CV boots and joints. Immediately plug transmission openings with clean rags to prevent contamination.
⚠Driveshafts must be pried out evenly to avoid damaging differential side gears. Pry against the inner CV joint housing, not the axle shaft.
8
Support engine and transmission
Place a block of wood on a floor jack and position it under the engine oil pan to support engine weight. Position transmission jack under transmission with adapter or wood blocks to spread load. Secure transmission to jack with straps or chain.
9
Remove rear transmission mount
Remove the rear transmission mount bracket bolts from both the transmission side and chassis side. This mount is typically accessed from underneath. Note the orientation of mount for reinstallation.
Torque spec
Mounting Bolts26 Nm (19 lb-ft)
10
Remove remaining transmission-to-engine bolts
Remove all remaining transmission-to-engine mounting bolts including those accessible from underneath and from the side. There are typically 6-8 bolts total securing the transmission to the engine block. Verify all bolts have been removed before attempting separation.
Torque spec
Mounting Bolts26 Nm (19 lb-ft)
11
Separate and lower transmission
Carefully pull transmission away from engine, ensuring torque converter remains in transmission. Lower transmission jack slowly while guiding transmission clear of chassis components and hoses. Once clear, carefully lower to ground and move from under vehicle.
⚠️Ensure torque converter does not fall out during separation. If torque converter separates from transmission, fluid will drain out and converter may be damaged.
⚠Keep transmission level as you lower it. Tilting can cause torque converter to slide out.
12
Inspect and prepare for installation
Inspect torque converter drive plate (flywheel) for cracks or damage. Measure torque converter seating depth - it should be recessed approximately 15-20mm from bellhousing face. Replace transmission input shaft seal and driveshaft seals. Clean all mounting surfaces on engine block. Verify torque converter is fully seated by rotating and pushing inward until it clicks into place.
Torque spec
Flywheel Bolts95 Nm (70 lb-ft)
13
Install transmission
Raise transmission into position using transmission jack. Align transmission with engine, ensuring torque converter pilot engages with crankshaft. Do not use mounting bolts to draw transmission to engine - it should seat with minimal effort if properly aligned. Install all transmission-to-engine mounting bolts finger tight, then torque in stages starting with upper bolts.
⚠If transmission does not seat easily against engine block, do not force it. Remove and verify torque converter is fully seated.
Torque spec
Mounting Bolts26 Nm (19 lb-ft)
14
Install mounts and torque converter bolts
Install rear transmission mount and torque all mount bolts. Rotate crankshaft to access torque converter-to-drive plate bolts through starter opening or access cover. Install and torque all torque converter bolts in star pattern. Install access cover.
Torque spec
Mounting Bolts26 Nm (19 lb-ft)
Flywheel Bolts95 Nm (70 lb-ft)
Cover Screws10 Nm (8 lb-ft)
15
Reinstall driveshafts and subframe
Install new driveshaft seals if not already done. Remove plugs from transmission and insert driveshafts fully until they click into place. Pull outward on each to verify they are locked in. Reinstall subframe, suspension components, and ball joints. Torque all fasteners to specification.
16
Reconnect all connections and components
Reconnect shift cable and adjust if necessary. Reconnect all electrical connectors to transmission. Reinstall CVT cooler lines and secure with clips. Reinstall battery tray, battery, and air intake components. Reconnect negative battery cable.
17
Fill CVT with fluid
Fill transmission with Honda DW-1 ATF through dipstick tube or fill hole. Initial fill should be approximately 3.5-4.0 quarts. Start engine and cycle through all gear positions, pausing 2-3 seconds in each. With engine idling in Park, add additional fluid as needed. Final fluid level must be checked with CVT fluid at operating temperature (170-180°F or 77-82°C) using a scan tool.

Reassembly

Reinstall engine under covers and splash shields
Reinstall front wheels and torque lug nuts to specification
Lower vehicle to ground
Refill engine coolant if drained during removal
Double-check all electrical connections are secure
Verify shift cable adjustment - vehicle should start only in Park and Neutral

Verification

With engine at operating temperature and CVT fluid at 170-180°F (77-82°C), verify fluid level is in the HOT range on dipstick or within specification using fill plug method
Test drive vehicle and verify smooth shifting through all gear ranges
Check for fluid leaks around driveshaft seals, cooler lines, drain plug, and transmission-to-engine mating surface
Verify no abnormal noises from transmission or CV joints during acceleration and turning
Scan for diagnostic trouble codes and verify no transmission-related codes are present
Recheck CVT fluid level after test drive as fluid expands when hot

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