transmission carrier Genuine Porsche part 90137503100

HD Semi-solid engine mount set. Fits to existing engine or gearbox mount shell.
One kit includes 2 halves of mount, (2 kits required per car).

Fits:
Work as engine mounts in 1965-1989 911/912/930
Work as transmission mounts in 1972-1986 911/912/930 (915/930 Transmission Only)

Fits to number 8 on the diagram.

High Density engine/transmission mounts are the perfect compromise between stock rubber and our Semi-Solid mounts. Their heavy duty 25% higher durometer rubber construction makes them ideal for performance oriented cars, but still allows absorption of vibrations and noise associated with solid mounts. Installs in stock motor mount or transmission mount hangers replacing worn out factory rubber.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

91137504306

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Transmission / gearbox carrier.



Fits:
Porsche 911 upto 1971

Click 'Zoom in' for large parts diagram.
Diagram ref no 21

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

90137503100

The product you are viewing cross references to these numbers

Transmission / gearbox carrier.



Fits:
Porsche 911 upto 1971

Click 'Zoom in' for large parts diagram.
Diagram ref no 21

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

90137503100

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Powerflex Gearbox mount carrier bush.
Sold as a complete set for one gearbox mount

OEM Part Number: 90137503100 



Fits:
Porsche 911 1965-89
Porsche 912 1965-69

Made in our Dark Grey 80A durometer material to give the appearance of rubber but with the performance and longevity of polyurethane, reducing bush deflection by an impressive 50%. A small increase in NVH, usually at idle, should be expected when stiffening the connecting mount between the transmission and chassis. The harder the material used, the greater the NVH transmitted.

Click 'Zoom in' for large parts diagram.
Diagram ref no 21

Powerflex. Replacing your car rubber suspension bushes with Polyurethane Suspension Bushes will give you:

- Better road holding
- Constant steering geometry
- Increased tyre life
- More responsive steering
- Longer service life of suspension components

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

PFR57-414

The product you are viewing cross references to these numbers

Powerflex Powerflex Black Series Gearbox carrier mount bush.
Sold as a complete set for one gearbox mount

OEM Part Number: 90137503100 



Fits:
Porsche 911 1965-89
Porsche 912 1965-69

Made in our Dark Grey 80A durometer material to give the appearance of rubber but with the performance and longevity of polyurethane, reducing bush deflection by an impressive 50%. A small increase in NVH, usually at idle, should be expected when stiffening the connecting mount between the transmission and chassis. The harder the material used, the greater the NVH transmitted.

Click 'Zoom in' for large parts diagram.
Diagram ref no 21

Powerflex. Replacing your car rubber suspension bushes with Polyurethane Suspension Bushes will give you:

- Better road holding
- Constant steering geometry
- Increased tyre life
- More responsive steering
- Longer service life of suspension components

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

PFR57-414BLK

The product you are viewing cross references to these numbers

Powerflex Gearbox mount carrier bush.
Sold as a complete set for one gearbox mount

OEM Part Number: 90137503100 



Fits:
Porsche 911 1965-89
Porsche 912 1965-69

Made in our Dark Grey 80A durometer material to give the appearance of rubber but with the performance and longevity of polyurethane, reducing bush deflection by an impressive 50%. A small increase in NVH, usually at idle, should be expected when stiffening the connecting mount between the transmission and chassis. The harder the material used, the greater the NVH transmitted.

Click 'Zoom in' for large parts diagram.
Diagram ref no 21

Powerflex. Replacing your car rubber suspension bushes with Polyurethane Suspension Bushes will give you:

- Better road holding
- Constant steering geometry
- Increased tyre life
- More responsive steering
- Longer service life of suspension components

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

PFR57-414H

The product you are viewing cross references to these numbers

HD Semi-Solid Engine Mount Set.

Enhance drivetrain precision and performance with the HD Semi-Solid Engine / Transmission Mount Set, designed specifically for Porsche 911 and 912 models
These heavy-duty mounts replace the factory rubber units with a semi-solid, high-durometer compound — around 25 % firmer than standard — providing improved control and response without sacrificing comfort.
The semi-solid design effectively reduces engine and gearbox movement under acceleration, braking, and cornering, giving sharper throttle response, smoother gear changes, and tighter handling stability.
One kit includes 2 halves of mount, (2 kits required per car).

Fits:
Work as engine mounts in 1965-1989 911/912/930
Work as transmission mounts in 1972-1986 911/912/930 (915/930 Transmission Only)

Fits On To Diagram Ref No 8 And 49

What This Product Does:

• In the Heavy Dusty semi-solid version, the stiffer rubber reduces unwanted flex while still providing some damping, hence a compromise between fully soft and fully rigid (solid) mounts.

Symptoms / Indications That Replacement Or Upgrading Is Needed:

• Engine / gearbox movement or “rocking” under throttle or deceleration
• Clunking or banging noises from the engine bay when shifting or applying torque
• Increased vibration in the cabin or floorboard
• Misalignment over time, causing stress or wear in driveshafts, couplings, or mount brackets
• Feel of looseness or lag in throttle response or drivetrain “lash”

Why Upgrading to HD Semi-Solid Mounts Matters:

• Sharper Response & Less Flex - Because mounts deflect less, the engine / gearbox stays more stable under load, improving throttle response, shift feel, and power delivery.
  
• Better Drivetrain Alignment - Less movement helps maintain correct angle relationships between engine, gearbox, driveshafts, etc., reducing stress and wear.
  
• Improved Stability Under Load - During hard cornering, braking, or acceleration, stiffer mounts help avoid drivetrain “twist” or slop, which can upset handling balance.
  
• Dampening Retained - Semi-solid design still absorbs vibration and noise more than fully rigid mounts, providing a balanced tradeoff for street use.
  
• Straightforward Installation - Because the inserts fit existing mount shells, installation is simpler — no need for custom brackets or drastic modifications.
  
• Good for Performance / Restoration Builds - Especially in cars that see spirited driving or occasional track use, the HD semi-solid mounts are a common upgrade that improves control without completely sacrificing comfort.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

91137504306

The product you are viewing cross references to these numbers