Enter your VAT number here and click Verify:
Your details have been verified. VAT number registered to:
,
.
Your order will now be zero rated for VAT purposes. We reserve the right to verify these details after your order request has been made and reinstate VAT if required.
Your VAT details were not recognised or were invalid. Your VAT number must be matched to your Billing Country as specified above. This is currently specified as . You do not need to enter the country code part of your VAT number as this has already been selected in your billing address details above.
The VAT number checking service is currently offline. Please supply your VAT details within the comments or special instructions field below and we will apply a VAT discount after placing your order request.
Gearbox Anchors / Stops / Blocks
- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1978-1989 3.3L Turbo (930)
Gearbox Detent for 915 Gearbox
Sold each
Fits:
- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1978-1989 3.3L Turbo (930)
Diagram Ref No 21
What This Product Does
The detent operates within the transmission selector assembly, where it provides a locating and retaining action. Depending on the gearbox application, it is installed within the transmission case, gear housing or front transmission cover.
Functions
- Provides a defined locating point within the selector mechanism
- Assists with retaining the associated internal component in position
- Supports controlled selector movement inside the gearbox
- Replaces a worn or damaged detent during transmission inspection or rebuilding
Technical Details
- Part number: 91530313100
- Manufacturer: Porsche
- Component description: transmission detent or detent catch
- Identified as a short detent in applicable Type 915 transmission diagrams
- Diagram quantity varies between one, three and four according to the transmission assembly
Symptoms of Fault
- Notchy or difficult gear selection
- Less positive engagement through the selector mechanism
- A selected gear unexpectedly disengaging
- Visible scoring, wear or deformation found during gearbox dismantling
- Metal particles in drained transmission oil requiring further internal inspection
Why Replacement Matters
Wear or damage to the detent can affect the intended movement and retention of the selector assembly. Renewal during a transmission overhaul helps return the mechanism to its specified configuration. The corresponding spring, sleeve, locking components, selector parts, casing surfaces, seals and transmission oil should also be inspected while the gearbox is dismantled.
FAQs
- Is this detent used with a Type 915 gearbox?
It is identified in Type 915 transmission case and gear housing diagrams, as well as selected related transmission assemblies. Confirm the gearbox code and part number before ordering. - How many detents are required?
The quantity depends on the particular transmission and diagram. The supplied exploded diagrams specify assemblies using one, three or four pieces. - Should associated parts be checked?
Yes. Inspect the spring, sleeve, selector components, locking parts, housing surfaces and lubricant for evidence of wear or damage.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
91530313100
The product you are viewing cross references to these numbers
Porsche Gearbox Anchors, Stops & Blocks | Secure Transmission Positioning & Drivetrain Control
Gearbox anchors, stops, and blocks are vital structural components that stabilise and secure your Porsche’s gearbox under torque load. These parts prevent unwanted gearbox movement, maintain proper alignment with the engine and driveshafts, and protect surrounding components from vibration or stress.
At Design911, we supply precision-engineered gearbox anchors, stops, and mounting blocks designed to match or exceed original performance standards. Crafted from high-strength aluminium, steel, or reinforced polymer, these components ensure optimal gearbox stability under both road and performance conditions.
Whether you’re replacing worn anchors on a daily driver or upgrading a track-prepared Porsche, our gearbox anchors and stops deliver improved drivetrain control, reduced vibration, and long-term reliability.
What Do Gearbox Anchors, Stops & Blocks Do?
These components serve as the mechanical connection points that keep the gearbox firmly in place while allowing controlled movement during acceleration and braking.
Core Functions:
- Maintain correct gearbox alignment within the chassis.
- Absorb torque loads to prevent drivetrain movement.
- Support consistent gear engagement and shifting precision.
- Reduce vibration and protect mounts, linkages, and couplings.
Without properly functioning gearbox anchors or stops, the transmission can shift under load — causing excessive movement, misalignment, or even component damage during gear changes or hard acceleration.
Why Do Gearbox Anchors, Stops & Blocks Fail or Wear Out?
Over time, continuous stress, heat, and vibration weaken or deform these components, especially in high-performance or ageing vehicles.
Common Causes of Failure Include:
- Metal fatigue or cracking under torque stress.
- Corrosion or oxidation from road debris or moisture.
- Rubber or polymer degradation in hybrid anchor designs.
- Damage from harsh impacts or poor alignment.
- Loose fittings or worn mounting bolts causing play.
Once compromised, gearbox anchors can allow excess movement — resulting in drivetrain noise, gear misalignment, or premature wear to transmission mounts and couplings.
Why Replace Your Porsche Gearbox Anchors, Stops & Blocks?
Replacing worn or damaged gearbox anchors ensures your transmission remains securely mounted, properly aligned, and free from unwanted movement. Upgraded anchors or reinforced stops enhance stability and control, particularly in modified or high-performance Porsches.
Key Benefits:
- Restores proper gearbox alignment and support.
- Prevents driveline movement and gear misalignment.
- Reduces vibration, noise, and stress on surrounding parts.
- Improves gear change accuracy and drivetrain feel.
- Constructed from high-strength materials for long life.
- Suitable for road, restoration, or track applications.
For optimal performance, anchors and stops should be inspected and replaced during clutch, mount, or gearbox servicing.
Highlights
- Premium Porsche gearbox anchors, stops, and blocks.
- Designed for strength, precision, and long-term durability.
- Minimises drivetrain movement and vibration.
- Perfect fitment for Porsche 911, Cayman, Boxster, and more.
- Reinforced for performance, restoration, or repair use.
- Essential for maintaining transmission stability and balance.