As an authorized Thorney Motorsport facility, we provide expert diagnosis and repair of McLaren SSG dual-clutch transmissions. We fix the dreaded weep hole leak, replace clutches, and rebuild gearbox internals — all without the dealership price tag.
As a Thorney Motorsport Toronto facility, our technicians specialize in the Graziano-built SSG dual-clutch transmission. From weep hole leaks to full clutch replacements, we handle it all.
Weep Hole Leak Repair
The dreaded weep hole leak is caused by an internal transmission pump seal failure. We properly diagnose and repair this issue, preventing gear oil from contaminating the clutch fluid circuit and avoiding catastrophic gearbox damage.
Clutch Replacement
McLaren's wet dual-clutch packs wear over time, especially with aggressive driving or improper fluid levels. We replace worn clutch packs, restoring smooth, crisp shifts and full engagement across all seven gears.
Solenoid & Valve Body Repair
Debris scoring on solenoid pistons and clogged film-ways are common failure points. We clean, recondition, or replace solenoid assemblies and the Synchro Actuation Valve block to restore proper hydraulic shift pressure.
Transmission Fluid Service
Many McLarens leave the factory under-filled, accelerating internal wear. We perform precision fluid service using only McLaren-approved transmission oil and clutch hydraulic fluid to manufacturer specifications.
Seal & Gasket Replacement
Internal rubber and poly seals degrade over time, causing fluid leaks and pressure loss. We replace all worn seals, O-rings, and gaskets throughout the transmission to eliminate leaks and restore shift quality.
Full Gearbox Rebuild
For transmissions with extensive internal wear or multiple failure points, we offer a complete rebuild service including disassembly, ultrasonic cleaning, inspection, and replacement of all worn components.
The Weep Hole Leak Explained
One of the most common and misunderstood McLaren transmission issues — and we know exactly how to fix it.
What Is the Weep Hole?
The weep hole is a small diagnostic opening at the bottom of the McLaren transmission case. It connects to an internal sealed cavity near the transmission pump. When the pump seal that separates gear oil from clutch fluid begins to fail, fluid weeps out through this hole rather than mixing internally.
If you see fluid pooling underneath your McLaren near the transmission, it is likely the weep hole leak. While a small drip may not cause immediate shift issues, ignoring it risks catastrophic damage if gear oil pressurizes and contaminates the clutch system — which can also damage the airbrake hydraulics.
How We Fix It
Unlike quick-fix solutions that simply plug the hole, our approach addresses the root cause. We inspect the internal pump seal condition, evaluate fluid contamination levels, and perform a proper repair that prevents future gear oil and clutch fluid cross-contamination.
Full diagnostic scan of transmission pressures and fluid condition
Internal pump seal inspection and replacement
Fluid contamination testing and flush if needed
Proper weep hole restoration and sealing
Post-repair pressure testing and road verification
Why Choose Foreign Automotive
25+Years Experience
ThorneyMotorsport Toronto
OEMParts & Fluids
50%+Less Than Dealer
Warning Signs Your McLaren Needs Transmission Service
Recognizing these symptoms early can prevent costly damage and keep your McLaren performing at its best.
High Clutch Temperature Warning
If your dashboard displays a clutch temperature warning during normal driving, this indicates the clutch pack is slipping or transmission fluid is low, creating excessive friction and heat.
Hard or Delayed Shifts
Rough, hesitant, or delayed gear changes point to solenoid issues, low hydraulic pressure, or worn clutch packs. A glitching Transmission Control Module can also disrupt gear timing.
Gear Slipping
If gears slip or disengage unexpectedly — particularly between 2nd and 4th gear — it typically indicates advanced clutch wear or a faulty clutch cut-off valve solenoid.
Fluid Leak Under the Car
Any fluid pooling near the transmission area should be inspected immediately. It may be the weep hole leak, a breather valve issue, or a deteriorating external seal.
Burning Smell
A burning odour from the engine bay or rear of the vehicle can indicate overheating transmission fluid or clutch material friction. Do not continue driving — have it inspected promptly.
McLaren Models We Service
All McLaren models share the same Graziano SSG 7-speed dual-clutch transmission. We service the entire lineup.
MP4-12C
2011–2015. The model that launched the modern McLaren era. Known for higher DCT failure rates due to early production tolerances and factory fluid fill inconsistencies.
675LT
2015–2017. The Longtail variant of the 650S, built for track performance. The aggressive driving these cars see accelerates clutch wear and solenoid stress. Regular transmission fluid service is essential.
650S
2014–2018. Shares the same DCT as the 12C with refinements. Common issues include clutch wear, solenoid piston scoring, and the weep hole leak from pump seal degradation.
570S / 570GT
2015–2021. McLaren's most popular model with the highest volume of reported transmission issues. Prone to under-filling from the factory and breather valve fluid ejection.
600LT
2018–2021. Track-focused variant that sees harder use, accelerating clutch pack and solenoid wear. Transmission fluid maintenance is critical for these high-output models.
720S / 750S
2017–present. McLaren's flagship Super Series. Despite refinements, the same DCT platform means it shares the same potential failure points including seal degradation and solenoid issues.
Senna
2018–2020. McLaren’s ultimate track weapon. The extreme forces generated during track use place enormous stress on the DCT, making proactive maintenance critical for reliability.
765LT
2020–2022. The most aggressive Longtail yet. High-revving track use demands strict transmission fluid maintenance and proactive clutch monitoring to avoid costly failures.
GT / Artura
Newer McLaren models with evolved drivetrain architecture. We stay current with the latest McLaren transmission technology to provide expert service across the full range.
Frequently Asked Questions
Common questions about McLaren transmission repair at Foreign Automotive.
What is the McLaren weep hole leak and is it serious?
The weep hole is a diagnostic opening in the transmission case that leaks fluid when an internal pump seal fails. While a small leak may not cause immediate drivability issues, ignoring it can lead to gear oil contaminating the clutch fluid system, causing catastrophic gearbox failure. If you see fluid dripping near the transmission, have it inspected as soon as possible.
How often should I change my McLaren transmission fluid?
McLaren recommends changing the transmission fluid every 40,000 miles or 4 years, whichever comes first. The clutch hydraulic fluid, which is shared with the rear wing system, should be changed every 20,000 miles. Many McLarens come from the factory under-filled, so verifying the correct fluid level at every service is critical to preventing premature wear.
How much does a McLaren clutch replacement cost?
A full McLaren clutch replacement typically costs significantly less at our facility compared to dealership pricing. The job requires removing the subframe to access the transmission and is a labour-intensive procedure. We provide a detailed estimate after our initial diagnostic assessment, and our pricing is typically 50% or more below dealer rates.
Can you repair my McLaren transmission without replacing it entirely?
In most cases, yes. Many McLaren transmission failures are caused by relatively inexpensive components like rubber seals, solenoid pistons, or the Synchro Actuation Valve block. Our diagnostic process identifies the specific failure point, allowing us to perform targeted repairs rather than a full transmission replacement — saving you thousands.
Do you use OEM McLaren parts?
Yes. We use genuine McLaren-approved parts and fluids for all transmission work. This includes McLaren-specified transmission oil, clutch hydraulic fluid, seals, and gaskets. Using the correct specifications is essential for the longevity and proper operation of the SSG dual-clutch transmission.
McLaren Transmission Problems?
Do not wait for a small leak to become a major failure. Contact Foreign Automotive for expert McLaren transmission diagnosis and repair in Kitchener-Waterloo.
