2025-10-01

Heat Exchanger - Rear Drive Unit (3DU) (Remove and Replace)

Correction code 40305202 1.56 NOTE: Unless otherwise explicitly stated in the procedure, the above correction code and FRT reflect all of the work required to perform this procedure, including the linked procedures. Do not stack correction codes unless explicitly told to do so. NOTE: See Flat Rate Times to learn more about FRTs and how they are created. To provide feedback on FRT values, email ServiceManualFeedback@tesla.com. NOTE: See Personal Protection to make sure wearing proper PPE when performing the below procedure. See Ergonomic Precautions for safe and healthy working practices.

2025-10-01: Removed requirement to discard speed sensor to knuckle bolt. Add HEPA filter remove and install steps. Added halfshaft nut loosen and torque steps. Replaced alignment procedure with reference to check alignment specifications.
2024-02-27: Updated gearbox fluid to KAF 1.
2023-08-16: Updated EPB Service Mode reference.

Warning

This procedure is a DRAFT. Although it has been validated, Warnings and Cautions might be missing. Follow safety requirements and use extreme caution when working on or near High Voltage systems and components. Provide corrections and feedback to ServiceDevelopment@teslamotors.com.

Remove

Raise and support the vehicle. See Raise Vehicle - 2 Post Lift.
Open the LH front door and lower the LH front window.
Place the vehicle into Service Mode Plus. See Service Mode Plus.
Unlock the vehicle gateway. See Gateway (Unlock).
Run PROC_EPB_X_SERVICE-MODE-STARTvia Toolbox: (link).
Open the hood.
Remove the rear apron.

Note
14x clips
Remove the HEPA filter assembly. See Assembly - Filter - HEPA (Remove and Replace).
Power off vehicle from center display.

Note
Via Controls > Safety & Security > Vehicle Power > Power Off
Disconnect 12V negative terminal and first responders loop

Note
1x nut, 10mm, 6 Nm, 1x connector, Ensure vehicle is in park, climate control system is off, and vehicle is not charging before disconnecting 12V, Negative terminal should be disconnected before FRL, Allow 2 minutes for all electrical circuits to fully discharge
Loosen the rear RH rear halfshaft nut.

Note
32 mm deep impact socket
Remove the RH rear wheel. See Wheel Assembly (Remove and Install).
Remove RH rear brake caliper from knuckle and hang from body

Note
2x bolts, E18, 83 Nm, Discard bolts after removal
Raise vehicle fully and lower lift onto locks

Note
Set vehicle to comfortable working height, Make sure there's an audible click of the locks on both sides before lowering, otherwise vehicle may tilt to the side
Remove the mid aero shield.

Note
11x bolts, 10 mm, 5 Nm
Remove RH rear suspension cover

Note
1x bolt, 10mm, 6 Nm, 2x tabs
Lower vehicle partially and set lift onto locks

Note
Raise lift off locks, then hold lock release lever to keep locks free while vehicle is lowered, Set vehicle to comfortable working height
Install a spring compressor onto the RH rear coil spring.
Unbolt RH strut from body at top mount

Note
2x bolts, 15mm, 41 Nm
Remove nut securing RH rear stabilizer bar end link to stabilizer bar

Note
1x nyloc nut, 15mm, 55 Nm, Break nut loose then counter-hold ball joint with 5mm hex, Discard after removal
Remove stabilizer bar from RH rear end link

Note
May need to move the stabilizer bar up/down to get the correct angle to remove end link, Use a pry bar as needed for assistance
Remove RH rear wheel speed sensor from RH rear knuckle

Note
1x patch bolt, 10mm, 5 Nm, 1x grommet
Remove nut and bolt securing RH rear upper aft link to RH rear knuckle

Note
1x bolt, 1x nut, 21mm, 134 Nm
Remove nut and bolt securing RH rear upper fore link to RH rear knuckle

Note
1x bolt, 1x nut, 18mm, 76 Nm
Remove nut and bolt securing RH rear toe link to RH rear knuckle

Note
1x bolt, 1x nut, 18mm, 76 Nm, Recommend assistance
Remove nut and bolt securing RH rear lower fore link to RH rear knuckle

Note
1x bolt, 1x nut, 18mm, 76 Nm
Release RH halfshaft from drive unit

Note
1x U-bolt, 2x nuts, 10mm, Torque hand-tight, Wrap cable around inner joint, then tighten with U-bolt, Use slide hammer with cable eyelets to release, To avoid damage to the halfshaft boots and oil seals, exercise caution when removing
Remove RH halfshaft from rear drive unit

Note
Recommend assistance, Install axle seal plug
Install axle seal plug
Raise vehicle fully and lower lift onto locks

Note
Set vehicle to comfortable working height, Make sure there's an audible click of the locks on both sides before lowering, otherwise vehicle may tilt to the side
Place coolant drain container underneath vehicle
Release fir tree clip for lower coolant hose

Note
1x fir tree clip
Disconnect lower coolant hose to exchanger

Note
1x spring clip, Place a shop towel under the exchanger, Allow heat exchanger to drain, Allow hose to drain, Plug hose afterwards
Release fir tree clip for upper coolant hose

Note
1x fir tree clip
Disconnect upper coolant hose to exchanger

Note
1x spring clip, Allow heat exchanger to drain, Allow hose to drain, Plug hose afterwards
Remove the fasteners securing the heat exchanger to the drive unit

Note
2x bolts, EP10, 5 Nm + 30 degrees, The number of fasteners may vary due to production changes
Remove the heat exchanger from the drive unit assembly

Note
Do not pry against the RDU or the heat exchanger, Damage may occur, It may be necessary to gently work the heat exchanger up and down to free it from the RDU, Do not allow coolant to enter oil passages of drive unit, Prevent cross-contamination

Install

Install the heat exchanger onto the rear drive unit

Note
Lightly coat o-rings with clean KAF 1 gearbox fluid. Do not pinch or deform o-ring during install, Ensure the heat exchanger is fully seated, Do not allow coolant to enter oil passages of drive unit, Prevent cross-contamination
Secure inverter to cooler hose to cooler

Note
1x spring clip, Perform push-pull-push test to make sure hose is fully seated
Fasten fir tree clip for upper coolant hose

Note
1x fir tree clip
Secure coolant outlet hose to drive unit cooler

Note
1x spring clip, Perform push-pull-push test to make sure hose is fully seated
Fasten fir tree clip for lower hose

Note
1x fir tree clip, Remove used shop towels
Remove coolant drain container from underneath vehicle
Lower vehicle partially and set onto locks

Note
Raise lift off locks, then hold lock release lever to keep locks free while vehicle is lowered, Set vehicle to comfortable working height
Install RH halfshaft to drive unit

Note
Remove axle seal plug if necessary, Caution not to damage the axle seal during installation, Recommend assistance
Apply Molykote M-77 to outboard side of RH front halfshaft assembly

Note
Clean if necessary, Apply no more than 1 gram to axle only
Install RH rear toe link to knuckle and install nut and bolt hand tight

Note
1x bolt, 1x nut, 18mm, 76 Nm, Recommend assistance, Torque at later step
Install RH rear upper fore link to knuckle and install nut and bolt hand tight

Note
1x bolt, 1x nut, 18mm, 76 Nm, Recommend assistance, Torque at later step
Install RH upper aft link to knuckle and install nut and bolt hand tight

Note
1x bolt, 1x nut, 21mm, 134 Nm, Recommend assistance, Torque at later step
Install RH rear lower fore link to knuckle and install nut and bolt hand tight

Note
1x nut, 18mm, 76 Nm, Torque at later step
Install RH rear wheel speed sensor to knuckle

Note
1x patch bolt, 10mm, 5 Nm, Install new patch bolt，1x grommet
Position RH rear end link into stabilizer bar

Note
Adjust the end link to align with stabilizer bar, Also may need to move the stabilizer bar up/down to get the correct angle to install end link
Install nut securing RH rear end link to stabilizer bar

Note
1x nyloc nut, 15mm, 55 Nm, Counter-hold ball joint with 5mm hex, Install new nyloc nut, Mark bolt after torque
Install bolts securing RH damper to body at top mount

Note
2x bolts, 15mm, 41 Nm
Install RH rear brake caliper onto knuckle

Note
2x bolt, E18, 83 Nm, Install new bolts, Remove the S-hook from vehicle
Remove bolt securing RH rotor to hub

Note
1x bolt, 10mm, 5 Nm
Install hub jack adapter onto RH rear hub

Note
5x lug nuts, 21mm, Hand tight
Position and raise support stand to simulate RH rear suspension at ride height
Use rear ride height torque gauge to verify RH suspension is set to ride height specification

Note
May need to slightly adjust stand or compression tool
Measure from bottom of quarter panel to center of axle as a secondary check to make sure RH suspension is set to ride height

Note
Distance should be 427 mm
Torque bolt securing RH rear toe link to knuckle

Note
1x bolt, 18mm, 76 Nm, Mark with paint pen
Torque bolt securing RH rear upper fore link to knuckle

Note
1x bolt, 18mm, 76 Nm, Mark with paint pen
Torque bolt securing RH rear lower fore link to knuckle

Note
1x bolt, 18mm, 76 Nm, Mark with paint pen
Torque bolt securing RH rear upper aft link to knuckle

Note
1x bolt, 21mm, 134 Nm, Mark with paint pen
Remove support stand from underneath RH suspension
Remove hub jack adapter from RH rear hub

Note
5x lug nuts, 21mm, Hand tight
Install bolt securing RH rotor to hub

Note
1x bolt, 10mm, 5 Nm
Remove spring compressor from RH rear coil spring
Raise vehicle fully and lower lift onto locks

Note
Set vehicle to comfortable working height, Make sure there's an audible click of the locks on both sides before lowering, otherwise vehicle may tilt to the side
Disconnect oil pump connector

Note
1x connector, Do not push down on red tab, Pull red tab to disengage lock, Pull again to release connector
Connect the 12V power supply to oil pump

Note
1x connector
Remove fill plug from RDU

Note
1x plug, 8mm Allen, 15 Nm
Install dipstick into fill port
Run the oil pump power supply for 1 minute
Wait 1 minute for fluid to settle
Pull out dipstick to verify fluid is at correct level

Note
Make fluid level adjustment if necessary
Install fill plug into RDU

Note
Install new fill plug O-ring, 1x plug, 8mm Allen, 15 Nm
Disconnect 12V power supply tool from oil pump
Connect oil pump connector

Note
1x connector, Engage locking tab
Install RH rear suspension cover

Note
1x bolt, 10mm, 6 Nm, 2x tabs
Apply Loctite 222 onto mid aero shield bolts and install mid aero shield

Note
9x bolts, 10mm, 5 Nm
Lower vehicle partially and set onto locks

Note
Raise lift off locks, then hold lock release lever to keep locks free while vehicle is lowered, Set vehicle to comfortable working height
Install RH rear wheel

Note
5x nuts, 21mm, 175 Nm, Start lug nuts by hand before using power tool
Lower vehicle until tires are touching the ground

Note
Raise lift off locks, then hold lock release lever to keep locks free while vehicle is lowered
Torque RH rear wheel

Note
5x nuts, 21mm, 175 Nm
Install RH rear wheel cap

Note
1x cap, Align valve stem with wheel cap cavity
Torque the RH rear halfshaft nut.

300 Nm (221.2 lbs-ft)

Note
32 mm deep impact socket
Remove coolant bottle cap
Inspect coolant level and top off as necessary

Note
Ensure that the fluid level is at the Max line
Connect first responder loop and 12V negative terminal

Note
1x nut, 10mm, 6 Nm, 1x connector, Engage locking tab, Connect FRL first before connecting 12V to avoid damage to car computer
Press and hold park button to release EPB service mode

Note
Remove wheel chocks if necessary
Open LH front door
Connect to vehicle using Toolbox 3.0
Select ‘Actions/Autodiag’ tab and search for ‘ Purge'
Select ‘
TEST_VCFRONT_X_THERMAL-COOLANT-AIR-PURGE
via Toolbox: (link)via Service Mode:
Thermal ➜ Actions ➜ Coolant Purge Stop or Coolant Purge Start
Thermal ➜ Coolant System ➜ Coolant Purge Start
via Service Mode Plus:
Drive Inverter ➜ Front Drive Inverter Replacement ➜ Coolant Air Purge
Drive Inverter ➜ Rear Drive Inverter Replacement ➜ Coolant Air Purge
Drive Inverter ➜ Rear Left Drive Inverter Replacement ➜ Coolant Air Purge
Drive Inverter ➜ Rear Right Drive Inverter Replacement ➜ Coolant Air Purge
Drive Unit ➜ Front Drive Unit Replacement ➜ Coolant Air Purge
Drive Unit ➜ Rear Drive Unit Replacement ➜ Coolant Air Purge
’, click ‘Run’, and allow routine to complete
Note
Make sure vehicle is not in drive state, Plan is still running despite the stop message, Coolant pumps will be audible, Test lasts approximately 10 mins, Idle speed = ~1500 RPM, Test will vary speeds from 3500-6500 RPM and actuate valve between SERIES and PARALLEL, Putting vehicle into drive state will stop this routine, If speeds hover at 7000 RPM, that means the pumps are air locked, perform vacuum fill again, Continue to add coolant and purge until the coolant level reaches between the NOM and MAX Lines on the bottle, Select ‘X’ at top right of window to close once complete
Inspect coolant level and top off as necessary

Note
Ensure that the fluid level is at the Max line
Install coolant bottle cap
Install rear apron

Note
14x clips. Hold rear wall of frunk to keep from flexing while engaging front clips
Install the HEPA filter assembly. See Assembly - Filter - HEPA (Remove and Replace).
Close the hood.
Remove the HSD cable from Ethernet port to disconnect Toolbox 3.0 from vehicle
Raise all windows and close all doors.
Remove the vehicle from the lift. See Raise Vehicle - 2 Post Lift.
Review wheel alignment requirements and add correction codes as needed. See Alignment Requirement - Suspension.

2020–2024 Model Y Service Manual

Heat Exchanger - Rear Drive Unit (3DU) (Remove and Replace)

Remove

Install

Figure 1

Figure 2

Figure 3