ISR Performance Transmission Mount - Nissan 240SX S13 / S14 (KA24DE / SR20DET) (IS-TMK-240)

Eliminate drivetrain slop and sharpen your 240SX's shift feel with the ISR Performance transmission mount. Engineered for the Nissan 240SX S13 and S14 with KA24DE or SR20DET drivetrains, this performance transmission mount reduces transmission movement under load for more precise, confidence-inspiring shifts and improved drivetrain response.

Key Features:

• Performance transmission mount
• Reduces transmission movement under load
• Improved shift feel and drivetrain response
• Fits Nissan 240SX S13 and S14
• Compatible with KA24DE and SR20DET drivetrains
• Direct bolt-on replacement
• ISR Performance quality and engineering

Performance Benefits:

• Reduced Drivetrain Movement: Firmer mount keeps transmission in position under acceleration and braking
• Improved Shift Feel: Less transmission movement translates to more precise, direct gear changes
• Better Response: Reduced drivetrain slop improves throttle and shift response
• Durability: Performance materials outlast factory rubber significantly
• Direct Fit: Bolt-on replacement for factory transmission mount
• SR20DET Compatible: Fits both factory KA24DE and popular SR20DET swap drivetrains

Specifications:

• Brand: ISR Performance
• Part Number: IS-TMK-240
• Product: Performance Transmission Mount
• Fitment: Direct bolt-on replacement
• Weight: 1.1 lbs
• Barcode: IS-TMK-240

Fitment Information:

• 1989-1994 Nissan 240SX S13 - KA24DE and SR20DET
• 1995-1998 Nissan 240SX S14 - KA24DE and SR20DET
• Note: Verify compatibility with your specific transmission for SR20DET swap applications
• Installation: Professional installation recommended

What's Included:

• ISR Performance transmission mount (IS-TMK-240)
• Mounting hardware
• Installation instructions

Installation Notes:

• Professional installation recommended
• Support transmission with a jack before removing old mount
• Remove factory transmission mount hardware
• Install ISR Performance mount using included hardware
• Torque all fasteners to manufacturer specifications
• Lower transmission onto new mount carefully
• Check for clearance issues before driving

Why Replace Your Transmission Mount?

The transmission mount secures the transmission to the chassis, holding it in position while absorbing the torque and vibration generated by the drivetrain. Factory rubber transmission mounts are designed to provide compliance and vibration isolation, but they degrade over time — the rubber cracks, hardens, and eventually tears, allowing the transmission to move excessively under load. On a 240SX, a worn transmission mount causes vague, imprecise shift feel as the transmission shifts position during gear changes, and can cause driveline vibration and clunking under acceleration and deceleration. Replacing a worn mount restores proper drivetrain positioning and shift feel.

Performance Mount vs. Factory Rubber:

ISR Performance's transmission mount uses firmer materials than the factory rubber mount, reducing the amount of transmission movement under load. This firmness provides a more direct, precise shift feel — the transmission stays in position during gear changes rather than moving with each shift. The trade-off is a slight increase in NVH (noise, vibration, harshness) transmitted into the cabin compared to a factory rubber mount, which is acceptable for performance-oriented 240SX builds. For daily-driven builds where NVH is a priority, the factory rubber mount may be preferable if it is not worn.

KA24DE and SR20DET Compatibility:

The IS-TMK-240 is compatible with both the factory KA24DE drivetrain and the popular SR20DET engine swap. The SR20DET swap is one of the most common modifications on the 240SX platform, replacing the factory KA24DE with the turbocharged SR20DET from the Nissan Silvia for significantly increased power potential. The transmission mount location and mounting points are shared between the KA24DE and SR20DET drivetrains in the 240SX chassis, making the IS-TMK-240 a versatile choice for both stock and swapped builds. Verify compatibility with your specific SR20DET transmission configuration before ordering.

Replace as a Set - Engine and Transmission Mounts:

When replacing the transmission mount on a 240SX, it's strongly recommended to inspect the engine mounts at the same time. Engine and transmission mounts work together to hold the entire drivetrain in position, and they wear at similar rates. If the transmission mount is worn, the engine mounts are likely approaching the end of their service life as well. Replacing all drivetrain mounts together ensures the entire drivetrain is properly secured and provides consistent performance improvement across all mounts. ISR Performance offers engine mounts for the 240SX platform to complement the transmission mount.

Signs of a Worn Transmission Mount:

• Vague or imprecise shift feel
• Clunking or thudding under acceleration or deceleration
• Visible transmission movement when revving engine in neutral
• Driveline vibration at certain RPM ranges
• Difficulty engaging gears smoothly
• Transmission appears to have shifted position in the tunnel

240SX Platform Context:

The Nissan 240SX (S13 and S14) is one of the most popular platforms in the North American performance and drift community, prized for its rear-wheel-drive layout, balanced chassis, and extensive aftermarket support. Whether running the factory KA24DE or a popular SR20DET swap, maintaining proper drivetrain mount condition is essential for reliable, precise operation. A well-maintained drivetrain mount setup is particularly important for drift and performance driving, where the drivetrain is subjected to repeated hard acceleration, deceleration, and direction changes that stress the mounts significantly.

Why ISR Performance?

ISR Performance is a respected manufacturer of performance drivetrain and suspension components for popular JDM platforms, known for their quality construction and correct fitment on the 240SX platform. Their drivetrain components are trusted by 240SX enthusiasts worldwide for reliable performance and genuine improvement over worn factory components. ISR Performance's focus on the S13/S14 platform ensures their mounts are engineered to the correct specifications for reliable, long-term performance.

Perfect For:

• Nissan 240SX S13 and S14 builds with worn or failed transmission mount
• KA24DE and SR20DET 240SX builds wanting improved shift feel
• Drift and performance 240SX builds needing reduced drivetrain movement
• 240SX drivetrain refreshes replacing all worn mounts
• Anyone seeking ISR Performance quality for their S13/S14 drivetrain

Perfect For: Nissan 240SX S13 and S14 owners (KA24DE or SR20DET) seeking ISR Performance transmission mount for reduced drivetrain movement, improved shift feel, and reliable drivetrain positioning.

Pro Tip: Replace the engine mounts at the same time — they wear together, the labour overlap is significant, and a complete drivetrain mount refresh makes a noticeable difference in shift feel and drivetrain response on the 240SX.

Direct Bolt-On: Fits S13 (1989-1994) and S14 (1995-1998). KA24DE and SR20DET compatible. 1.1 lbs. Professional installation recommended. Inspect engine mounts at same time.

Sharpen your 240SX's drivetrain with ISR Performance transmission mount — reduced movement, improved shift feel, KA24DE and SR20DET compatible.