Gearbox Mounts

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

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PFR57-414BLK

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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
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PFR57-414H

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Gearbox mount cup washer.
Sold each

Fits:
Porsche 911 1965-89
Porsche 911 (930) Turbo 1975-89
Porsche 964 CARRERA RS
Porsche 993 CARRERA RS

Diagram Ref No 6

Gearbox mount cup washer. 
Fits above and below the engine/transmission mounts.



Fits:
Porsche 911 1965-89
Porsche 911 (930) Turbo 1975-89
Porsche 964 CARRERA RS
Porsche 993 CARRERA RS

Click 'Zoom in' for large parts diagram.
Diagram Ref No 6

Price shown is for each.

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90130531100PRM

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Gearbox mount set (4 pcs).
Fits to gearbox mount 91137503109 / 91137503110.

Fits:
Porsche 911 1987-89 G50 Gearbox equipped cars

These replacement transmission mounts are the same durometer as your factory bushings. Tired of the drivetrain slop that your worn bushings are creating, but don't want to move up to a harder durometer? These are your answer.

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91137503110

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Gearbox mounting washer G50
2 required per car



Fits:
Porsche 911 G50 - 1986 to 1989

Click 'Zoom in' for large parts diagram.
Diagram ref no 9

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91137530500

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Gearbox Mounts Hexagon-Head Bolt Nut. M 8.



Fits:
Porsche 911/912 1965-89
Porsche 911 (930) Turbo 1975-89

Click 'Zoom in' for large parts diagram.
Diagram Ref No 9

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90007606402

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Gearbox Mounts Hexagon-Head Bolt Nut. M 8.
Gearbox mount hexagon-head bolt nut (part number 90007606402), designed for Porsche 911, 912, and 930 models (1965–1989). Manufactured to match original Porsche specifications, this M8 nut provides precise thread engagement, corrosion resistance, and dependable fastening strength for gearbox mounting applications.
Sold each.

Fits:
Porsche 911/912 1965 - 1989
Porsche 911 (930) Turbo 1975 - 1989

Diagram Ref No 9

Ideal for gearbox mount installations, transmission rebuilds, or hardware restorations on classic air-cooled Porsche models.

Over time, gearbox mounting hardware can corrode or lose torque retention due to heat, vibration, and age. A fresh nut ensures secure fastening and proper alignment of gearbox mounts. Replace during gearbox removal, rebuild, or mount replacement to maintain reliability and prevent drivetrain movement or noise.


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90007606402

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Gearbox Mounts Hexagon-Head Bolt. M 8 x 35.

Fits:
Porsche 911/912 1965-89
Porsche 911 (930) Turbo 1975-89

Diagram Ref No 7

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90007503203

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Gearbox rubber mount. Sold individually. 2 per gearbox required.


Fits:
Porsche 912

Click 'Zoom in' for large parts diagram.
Diagram Ref No 34.

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90230549201

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Gearbox rubber mount. Sold individually. 2 per gearbox required.



Fits:
Porsche 912

Click 'Zoom in' for large parts diagram.
Diagram Ref No 34.

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90230549201

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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.

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91137504306

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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.

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91137504306

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HD Semi-Solid Gearbox Mount Set (G50).

Improve drivetrain precision and shifting response with the HD Semi-Solid Gearbox Mount Set, designed for Porsche 911 models equipped with the G50 transmission (1987–1989).
This high-durometer semi-solid mount set replaces worn factory rubber bushings to deliver tighter drivetrain control, reduced movement, and improved alignment without introducing harsh vibration.
By minimizing gearbox motion under load, it enhances shift feel, stability, and feedback, creating a more connected and confident driving experience.
Sold As A Set Of 2 bushes (4 halves).

Fits:

• Porsche 911 1987-1989 3.2L G50

Fits On To Diagram Ref No 1

What This Product Does:

• The HD version is made from rubber with roughly 25 % higher durometer (i.e. stiffer) than original rubber mounts.
• It fits into the stock mounting brackets / spacers (i.e. “installs in stock transmission mount hangers replacing worn factory rubber”) 
• Because it is semi-solid rather than full solid, it retains some vibration isolation while cutting down drivetrain slop.

Symptoms Of Worn Or Soft Gearbox Mounts:

• Thuds, clicks, or knocking noises from the drivetrain, especially under shifting or torque load
• Excessive vibration felt in the cabin or floorboard
• Drivetrain “slop” or delayed response when you apply or remove throttle
• Shifts may feel less crisp due to slight misalignment or movement
• Additional stress on driveshafts, couplings, or mount brackets
• Transmission housing might appear to move or twist during load changes

Why Upgrading Matters:

• Improved Shift Feel & Response — with less drivetrain flex, shifts feel more direct
  
• Better Drivetrain Alignment Under Load — geometry stays more consistent under torque
  
• Reduced Clunk / Play — eliminates slack or movement that can degrade feedback
  
• Durability — stiffer rubber lasts longer, resists deformation, aging, and oil exposure
  
• Balanced NVH — better than stock in performance use, but not as harsh as full solid mounts
  
• Plug-and-Play Fitment — designed to use original mount brackets and spaces

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91137503110

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HD Semi-solid gearbox mount set of 2 (4 halves).
Fits to gearbox mount 91137503109

Fits:
Porsche 911 1987-89 Only for G50 Gearbox equipped cars

High Density 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 transmission mount hangers replacing worn out factory rubber.

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91137503110

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Hexagon head bolt for Gearbox carrier. M 12 X 1,5 X 68.
Sold each.

Fits:
Porsche 911 Carrera 1987 - 1989
with G5000,  G5001,  G5002,  G5050 gearbox

Diagram ref no 5



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91137531703

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