Coolant Delete Bypass for Large Drive Units (LDU)

Large Drive Unit — Tesla Model S/X Coolant Bypass (Coolant Delete Plate)

Early Tesla Large Drive Units (LDU) contain a coolant path through the rotor shaft that relies on internal seals.

Over time these seals commonly fail, allowing coolant to enter the motor or inverter — a failure mode that has affected a large number of early Model S and Model X vehicles.

A common failure symptom is an Isolation Fault Alert, which may indicate coolant intrusion and compromised high-voltage insulation inside the drive unit.

The coolant bypass / coolant delete plate eliminates this internal coolant path entirely, preventing the rotor seal failure that can lead to catastrophic drive-unit damage.

This upgrade can be performed as a DIY installation using our Coolant Delete Plate, or installed by our technicians at Gruber Motor Company in Phoenix.  The additional cost is labor since the entire drive train needs to be dropped out of the Tesla to gain access to the drive motor and coolant system to install this modified coolant delete option.

This modification does not remove thermal management in the drive train, but prevents further coolant ingress into the inverter electronics, or stator and rotor in the main drive motor.

Choose Your Path

Why these fail

• Rotor seal coolant path — Coolant travels through the rotor shaft using internal seals that eventually wear, harden, or lose sealing force.
• Coolant contamination — Once breached, coolant can damage bearings, stator windings, and inverter electronics.
• Escalation — Early warning signs such as hum, whine, vibration, or isolation faults can quickly become major drive-unit failure.

Our solution

• Coolant delete plate / bypass manifold — Eliminates the internal rotor coolant path entirely.
• Preventive protection — Helps stop the common rotor-seal coolant leak failure before it causes extensive damage.
• Professional installation available — Installed by Gruber Motor Company for owners who want a turnkey solution.
• Drive-unit health review — During installed service, we check for evidence of coolant ingress and related damage.
• Escalation path if needed — If your unit already shows contamination, noise, vibration, or isolation faults, we also offer complete rebuild services.

Service & coverage

Professional installation is performed at our Phoenix facility by EV drive-unit specialists. We validate the drive unit after service and support out-of-state customers with scheduling and transport options.