964
Porsche 964 Service & Maintenance
The 964 bridged old and new—the first 911 with power steering, ABS, and all-wheel drive, yet still gloriously air-cooled. These cars reward proper maintenance with an unmatched driving experience, and our technicians understand both their modern systems and their air-cooled soul.
Gold Meister Certified · PIWIS Factory Diagnostics · Stratford, CT
Our 964 Expertise
- 964 Carrera 2 and Carrera 4 specialists
- RS and RS America expertise
- 964 Turbo 3.3 and 3.6 service
- Speedster and Targa variants
- First-generation AWD system service
964 Services We Provide
Oil Service
Air-cooled specific lubricants with hydraulic lifter compatibility. Full visual inspection included.
G50 Transmission Service
Fluid change and inspection. Synchro assessment for shift quality issues.
AWD System Service (C4)
Transfer case fluid, center differential, and front differential service for Carrera 4 models.
ABS System Service
Early ABS system diagnosis and repair. Sensor and modulator service.
Engine Reseal
Comprehensive leak repair addressing case, timing covers, and oil return tubes.
964 Major Services
In-depth service procedures for the most critical 964 maintenance and repair work.
Engine Reseal & Rebuild
Engine-Out
964 Engine Specifics
The 964 uses the M64/01 (Carrera 2) or M64/02 (Carrera 4) 3.6-liter flat-six — the first 3.6L air-cooled engine. This engine introduced hydraulic lifters, eliminating mechanical valve adjustment but adding a new potential failure mode. The 3.6L engine also introduced cylinder head stud thread pulling in the aluminum case — a well-known issue where the stud threads strip out of the softer case material under thermal stress. Case savers (Time-Sert or Dilavar studs) are the standard repair, and we check for this during every engine-out service.
- M64/01 (C2) and M64/02 (C4): 3.6L flat-six with hydraulic lifters — no valve adjustment needed but lifters can fail
- Cylinder head stud thread pulling: aluminum case threads strip under thermal load — Time-Sert case savers are the fix
- Common leak points: oil return tubes, case half joint, timing covers, and valve cover gaskets
- Engine reseal is typically recommended every 80,000-100,000 miles or when leaks become significant
964 Rebuild Considerations
A full 964 engine rebuild follows the same fundamental process as other air-cooled rebuilds: case splitting, crankshaft and bearing inspection, cylinder and piston assessment, and cylinder head service. The 964's hydraulic lifters are inspected and replaced as a set if any are found to be collapsed or sticking. The dual-row chain tensioner upgrade is performed simultaneously if not already done. All fastener torque values are documented and the engine is test-run following factory break-in procedures.
- Hydraulic lifters tested for collapse and proper bleed-down rate — failed lifters replaced as a set per head
- Chain tensioner upgrade to dual-row performed during any engine-out service
- Cylinder head stud thread inspection: case savers installed wherever thread damage is found
- All seals, gaskets, and single-use fasteners replaced with genuine Porsche or quality equivalent parts
G50 Transmission Rebuild
Specialized
The G50 Gearbox
The 964 uses the Getrag G50 five-speed manual transmission with Borg-Warner synchros and a cable-operated shift mechanism. The G50 is generally considered the best manual gearbox fitted to air-cooled 911s, but after 30+ years of use, synchro wear (particularly 1st and 2nd gear), shift cable stretch, and bearing wear are common. A G50 rebuild restores the precise, short-throw shift feel that these gearboxes are known for.
- 1st and 2nd gear synchros wear first due to the largest speed differential during engagement
- Shift cable stretch causes increased shift throw and vague gate feel — cables are replaced during rebuild
- Main shaft and cluster bearings inspected for wear and replaced as needed
- Differential inspected: limited-slip units checked for clutch pack condition and proper preload
AWD System Overhaul (Carrera 4)
System
First-Generation 911 AWD
The 964 Carrera 4 was the first all-wheel-drive 911. Its AWD system uses a center differential, transfer case, and front differential to distribute torque. The system is heavier and more complex than later AWD systems, adding approximately 150 lbs over the Carrera 2. The center differential uses a planetary gear set with a viscous coupling that distributes torque based on wheel speed differences. Transfer case fluid, front and rear differential fluid, and center coupling condition all require regular maintenance.
- Center differential: planetary gear with viscous coupling — coupling fluid degradation causes lock-up or slip
- Transfer case: dedicated fluid change required every 30,000 miles — separate from engine and gearbox oil
- Front differential: independent fluid service with specific GL-5 gear oil
- AWD warning light diagnosis: PIWIS or 964-specific diagnostic tools identify specific fault locations
Dual-Mass Flywheel Conversion
Engine-Out
DMF Issues and Solutions
The 964 was among the first Porsches to use a dual-mass flywheel (DMF) to reduce drivetrain vibration. Over time, the DMF's internal springs and damper mechanism wear out, causing a characteristic rattling or knocking noise at idle and during gear changes. Failed DMFs cause drivetrain vibration that is transmitted through the clutch to the gearbox. The standard repair is replacement with a new DMF, but many 964 owners opt for a single-mass flywheel conversion using a Lightweight Flywheel kit, which eliminates the DMF failure mode entirely.
- DMF failure symptoms: rattling at idle, knocking during gear changes, drivetrain vibration
- Single-mass flywheel conversion eliminates the DMF failure mode — slightly increased drivetrain noise at idle is the tradeoff
- Lightweight Flywheel kits reduce rotating mass for quicker throttle response
- Clutch disc and pressure plate replaced simultaneously since the engine is out for flywheel access
Power Steering Overhaul
In-Situ
First Power-Steered 911
The 964 was the first 911 with power steering — a ZF hydraulic power steering system. After 30+ years, the power steering pump, reservoir, and high-pressure lines commonly develop leaks. The pump itself can become noisy as internal vanes wear. The power steering fluid reservoir plastic degrades and cracks, and the rubber high-pressure hoses deteriorate from heat exposure near the engine. A complete power steering overhaul addresses all components in the hydraulic circuit.
- ZF power steering pump: internal vane wear causes whining noise and reduced assist — rebuild or replacement
- Reservoir: plastic body cracks with age and heat exposure — replacement with new reservoir
- High-pressure hose: rubber deterioration from engine heat causes leaks — replaced with new hose assemblies
- Rack and pinion seals: rack seals can leak, causing fluid loss and contaminating the steering components
Common 964 Issues & Solutions
Every model has its common issues. Here's what we see and how we address them.
Oil Leaks
Engine reseal addressing multiple common leak points. Thermal cycling causes gasket deterioration.
Dual-Mass Flywheel (DMF)
DMF replacement when noise or vibration appears. Often converted to single-mass setup.
Power Steering Pump Leaks
Pump reseal or replacement. Reservoir and line inspection for deterioration.
Convertible Top Hydraulics
Hydraulic cylinder and pump service for Cabriolet and Targa models.
964 Service Intervals
Factory-recommended maintenance schedule to keep your 964 performing at its best.
Every 3,000-5,000 miles
- Oil and filter change
- Visual leak inspection
- Brake check
- Tire rotation
Every 15,000 miles
- Spark plugs
- Air filter
- Fuel filter
- Brake fluid flush
Every 30,000 miles
- G50 transmission fluid
- Differential fluid(s)
- Power steering fluid
- Complete chassis inspection
Why Your 964 Needs a Specialist
The 964 introduced systems that were new to the 911—power steering, ABS, and sophisticated all-wheel drive. Yet it retained the air-cooled engine that requires specialized knowledge. Our technicians bridge both worlds, understanding the modern conveniences while respecting the traditional powerplant.
964 Service FAQs
- What are the common engine problems on a Porsche 964?
- The 964's M64 3.6-liter engine is generally robust, but common issues include oil leaks from the engine case halves, thermal reactor exhaust stud failures, and dual-mass flywheel problems on early models. The Carrera 4 variant adds complexity with its AWD system, including a center differential and front differential that require regular fluid changes. Bore scoring is extremely rare on the 964 compared to later M96 engines.
- How do I know if my 964 dual-mass flywheel needs replacing?
- Symptoms of a failing dual-mass flywheel include a rattling noise at idle that disappears when the clutch pedal is pressed, vibrations through the drivetrain during acceleration, and a clunking sensation when shifting gears. Many 964 specialists recommend converting to a single-mass flywheel when the dual-mass unit fails, which eliminates the failure-prone design while providing a more direct throttle feel.
- Does the 964 Carrera 4 AWD system need special maintenance?
- Yes. The 964 C4 uses an early all-wheel-drive system with a center differential, front differential, and a driveshaft running through the center tunnel. All three units require dedicated fluid changes every 30,000 miles. The center differential clutch packs can wear over time, causing harsh engagement or judder during tight turns. The front CV boots should be inspected at every service for cracks or leaks.
- How much does a 964 G50 transmission rebuild cost?
- A G50 transmission rebuild on a 964 typically costs between $3,500 and $6,000 depending on the extent of wear. Common issues include second-gear synchro wear (a known weak point), worn shift forks, and bearing noise. A full rebuild includes new synchro rings for all gears, fresh bearings, seals, and a new shift detent assembly. The rebuilt unit should be filled with the correct GL-4 gear oil specification.
- What power steering issues are common on the 964?
- The 964's power steering system is prone to high-pressure hose leaks, worn pump seals, and rack-end leaks after 25 to 30 years of service. Symptoms include groaning noises when turning, fluid puddles under the front axle, and a heavy steering feel. A complete power steering overhaul includes rebuilding or replacing the pump, flushing the system, replacing all hoses, and resealing or replacing the steering rack.
Ready to Schedule Your 964 Service?
Contact us today to schedule your appointment. Our Gold Meister certified technicians are ready to provide factory-level care for your Porsche 964.
964 Service Areas
We serve 964 owners across CT, NY, NJ, MA, and PA.