If you own a Tesla Model S or Model X built between 2012 and 2020, there is a known design flaw in the rear drive unit (the Large Drive Unit, or LDU) that will eventually destroy the motor if left unaddressed. The fix is a coolant delete — a preventive procedure that takes the failed component out of the equation before it causes damage. We perform this service in Sacramento.
What’s the Problem?
The LDU’s rotor shaft has a factory coolant seal that, by design, fails over time. When it does, coolant enters the motor cavity. The damage cascade is severe: coolant shorts the stator windings, rusts or seizes the rotor, and can destroy the inverter electronics. Full drive unit replacement typically runs $10,000–$20,000 or more.
This isn’t a “might happen” issue — every LDU with the original rotor cooling design is considered at-risk. Tesla acknowledged this by releasing a redesigned unit (Revision U, late 2023) that reroutes coolant away from the rotor entirely. That’s effectively Tesla’s own admission that the original design doesn’t work long-term.
Which Vehicles Are Affected?
- All rear-wheel-drive Tesla Model S (2012–2020) — single motor, uses the LDU in the rear
- All Performance (P-series) dual-motor Model S and Model X — the rear unit on P85, P90D, P100D, Performance variants is the LDU
- Not affected: Standard dual-motor (non-Performance) Model S and Model X — those use a smaller rear unit (RDU) without the rotor cooling design flaw
If you’re not sure which drive unit your car has, we can verify from the VIN.
What Is the Coolant Delete?
The coolant delete caps off the rotor cooling circuit inside the LDU, stopping coolant from flowing through the area around the rotor shaft where the failing seal sits. The rest of the cooling system — the stator, inverter, and gearbox — continues to receive full coolant flow. In fact, because 100% of coolant volume now flows through the stator and inverter rather than splitting between the rotor and stator circuits, thermal performance for those components actually improves.
The procedure uses a purpose-built delete kit. No coolant is lost from the rest of the system. Drive unit performance is unchanged for normal driving — the rotor cooling circuit was only meaningful under extreme sustained loads like towing or sustained high-speed track use.
When Should You Do This?
Before the seal fails — that’s the entire point. If your LDU is already leaking coolant, you may still be able to perform the delete to stop further ingress, but internal damage assessment is needed first. Signs of an active coolant leak include:
- Wet or rusty speed sensors near the rear drive unit
- Coolant odor from the rear of the vehicle
- Unexplained coolant level loss
- Motor performance warnings or reduced power
If you own one of the affected vehicles and haven’t had this done, the time to do it is now — before Sacramento’s summer heat cycles accelerate seal degradation.
Our Process
- VIN verification and drive unit identification
- Visual inspection of the LDU for existing coolant leakage or seal damage
- Coolant delete kit installation — capping the rotor circuit
- Coolant system pressure test and top-off
- Post-service verification via Service Mode thermal data
Schedule Your LDU Coolant Delete
Call (916) 957-6884 or use our contact form. AT Automotive, 8561 Weyand Ave, Sacramento, CA 95828. Mon–Fri 10am–5pm.
For other Tesla Model S and Model X services, see our independent Tesla repair Sacramento page.
Our Warranty
Every repair at AT Automotive is backed by a 12-month / 12,000-mile warranty on parts and labor.