IMS Ancillary Parts

Additional rear main no. 8 bearing seal and housing.



Fits:
Porsche 986/987 Boxster 1997-2009
Porsche 996/997 1997-2009



Our team of technicians has developed a Rear Main Seal that corrects the notorious rear main oil leaks on the m96 and m97 engines. It has been developed to solve the twisting of the last journal of the crank shaft, reducing engine vibration and extending engine life. Prevent engine failure, by replacing your factory rear main seal with our upgraded rear main bearing seal and housing.

Features:
• prevents crank warping
• decreases engine vibrations
• prevents piston rod #6 failure
• extends engine life

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996986REAREPS

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Bearing shell for intermediate shaft (no/shoulder). Require 2 per engine, single item only.



Fits:
Porsche 993 1994-98
Porsche 996 Turbo/GT2/GT3
Porsche 997.1 Turbo/GT2/GT3
Porsche 997.2 GT2/GT3

This product supersedes Porsche's old part numbers:
- 90110113500
- 99310113500

Click 'Zoom in' for large parts diagram.
Diagram ref no 30.

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99610143571

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Bearing shell for intermediate shaft (no/shoulder). Require 2 per engine,  Price is Each one 



Fits:
Porsche 911 1965-89
Porsche 964 1989-94
Porsche 993 1994-98
Porsche 996 Turbo/GT2/GT3
Porsche 997.1 Turbo/GT2/GT3
Porsche 997.2 GT2/GT3

This product supersedes Porsche's old part numbers:
- 90110113500
- 99310113500

Click 'Zoom in' for large parts diagram.
Diagram ref no 30.

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99610143571

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Bearing shell for intermediate shaft (no/shoulder) - Sold as a pair 

Fits:
Porsche 911 - 1965 to 1989
Porsche 964 - 1989 to 1994
Porsche 993 - 1994 to 1998
Porsche 996 turbo / GT2 / GT3
Porsche 997.1 turbo / GT2 / GT3
Porsche 997.2 GT2 / GT3

This product supersedes Porsche's old part numbers:
- 90110113500
- 99310113500

Diagram ref no 30.

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99610143571

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Bearing shell for intermediate shaft (with shoulder).
Sold as PAIR / Requires 1 pair per engine

Pair, includes two bearing shells for the intermediate shaft, with one shell having a thrust shoulder. This bearing set is used to control axial play and radial support of the intermediate shaft. These precisely machined shells maintain the correct end-float, allowing accurate cam timing and smooth chain drive function under high RPM loads.

Fits:
Porsche 911 - 1965 to 1989
Porsche 914/6 - 1970 to 1976
Porsche 964 - 1989 to 1994
Porsche 993 - 1994 to 1998
Porsche 996 turbo / GT2 / GT3
Porsche 997.1 turbo / GT2 / GT3
Porsche 997.2 GT2 / GT3

This product supersedes Porsche's old part numbers:
- 91610113700
- 99310113700
- 99310113701

Diagram ref no 29.

These high-quality bearings resist wear, maintain stability under loading, and reduce friction. The shoulder shell is designed to handle axial load and keep the shaft from shifting. Both shells are matched to OE tolerances for crush and thickness to preserve ideal oil film clearance and ensure long life.

•  Location: Inside the engine case, at the intermediate shaft bore, flanking the connecting housing
•  Function: Provides radial support and axial control (shoulder shell) for the intermediate shaft

Over time, the intermediate shaft bearing shells may wear, lose geometry, or develop surface fatigue. Symptoms of failure include increased endplay (shaft axial movement), chain rattle, timing variation, and rapid wear of adjacent sprockets or tensioners.

This pair should be replaced during any engine rebuild, crankshaft pull, or when measurements show endplay outside specification. Installing fresh shells restores proper shaft location and timing stability for durable performance.

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99610113780

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Bearing shell for intermediate shaft (with shoulder).
Sold as PAIR/ Requires 1 pair per engine



Fits:
Porsche 964
Porsche 993 1994-98
Porsche 996 Turbo/GT2/GT3
Porsche 997.1 Turbo/GT2/GT3
Porsche 997.2 GT2/GT3

This product supersedes Porsche's old part numbers:
- 91610113700
- 99310113700

Click 'Zoom in' for large parts diagram.
Diagram ref no 29.

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99610113780

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Bearing shell for intermediate shaft (with shoulder).
Sold as single / Requires 2 per engine



Fits:
Porsche 911
Porsche 964
Porsche 993 1994-98
Porsche 996 Turbo/GT2/GT3
Porsche 997.1 Turbo/GT2/GT3
Porsche 997.2 GT2/GT3

This product supersedes Porsche's old part numbers:
- 91610113700
- 99310113700

Click 'Zoom in' for large parts diagram.
Diagram ref no 29.

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99610113780

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Intermediate Shaft Sprocket / Timing Gear
The Genuine Porsche 90110512504 Intermediate Shaft Sprocket is the factory-engineered drive gear that ensures precise timing chain operation in Porsche 911 air-cooled flat-six engines. Mounted on the intermediate shaft, it transfers rotation from the crankshaft to the camshafts, synchronizing valve timing for optimal performance, smooth running, and reliability.
Sold each, 2 required per vehicle.

Fits:
Porsche 911 1970 - 1989
Porsche 964 1989 - 1994
Porsche 993 1995 - 1998
Porsche 996 Turbo / GT2 2001 - 2005
Porsche 997.1 Turbo 2007 - 2009 (Engine type 9770)
Porsche 997.2 Turbo 2010 - 2013 (Engine type 9770)

Diagram ref no 28

Over time, timing gears can develop tooth wear, pitting, or chain-track distortion, leading to slack, noise, or incorrect valve timing.
Replace with a Genuine Porsche part during engine rebuilds or timing service to restore:
• Original chain engagement and cam phasing
• Factory reliability and noise reduction
• Long-term timing accuracy

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90110512504

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Intermediate Shaft Sprocket / Timing Gear.
The OE Match 90110512504 Intermediate Shaft Sprocket is designed as a direct-fit replacement for the factory sprocket mounted on the intermediate shaft in many Porsche 911 models. It meshes with the timing chain to drive cam or auxiliary components, maintaining precise synchronization between crankshaft and camshaft assemblies.
Sold each, 2 required per vehicle.

Fits:
Porsche 911 1970 - 1989
Porsche 964 1989 - 1994
Porsche 993 1995 - 1998
Porsche 996 Turbo / GT2 2001 - 2005
Porsche 997.1 Turbo 2007 - 2009 (Engine type 9770)
Porsche 997.2 Turbo 2010 - 2013 (Engine type 9770)

Diagram ref no 28

The sprocket features correctly machined tooth profiles and balanced construction to minimize wear and chain noise. Each gear is dimensionally matched to Porsche factory specifications, guaranteeing perfect alignment, secure fitment, and long service life.

Ideal for use during engine rebuilds, timing chain service, or IMS restoration, this replacement sprocket restores proper chain drive operation and timing integrity to your air-cooled flat-six engine.

•  Position: Mounted on the intermediate shaft (IMS) within the timing chain housing
•  Function: Transmits rotational motion from the timing chain to cam drive or auxiliary systems, helping to maintain engine valve timing integrity.
•  Symptoms of wear: Chain rattle, poor timing, metallic noise, valve timing error
•  Benefits: OEM fit and durability, precision-machined teeth, corrosion resistance
•  Installation: Direct-fit replacement; replace with new chain and tensioners for optimal timing performance

An intermediate shaft sprocket that’s worn, damaged, or misaligned can introduce timing error, chain slack, noise, or accelerated wear of timing components. Replace it when:
•  You are performing a timing chain or IMS overhaul
•  You find tooth damage, pitting, or wear

•  You observe abnormal chain noise, jump, or performance loss

Using a fresh sprocket restores the proper tooth engagement, accurate timing, and longevity of the cam drive system, helping avoid expensive engine damage.

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90110512504

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Thrust Bearing for Intermediate Shaft. Sold as EACH.



Fits:
Porsche 911 1965-89
Porsche 914
Porsche 930 Turbo 1975-89
Porsche 964 1989-94
Porsche 993 1995-98
Porsche 996 Turbo/GT2/GT3
Porsche 997.1 Turbo/GT2/GT3
Porsche 997.2 GT2/GT3

Click 'Zoom in' for large parts diagram.
Diagram ref no 31

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99610113780

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Tooth-Type Timing Chain Used To Connect The Engine’s Crankshaft To The Intermediate Shaft (IMS).

Fits:
Porsche 986 Boxster 2.7L 2001>>2004
Porsche 986 Boxster S 3.2L 2001>>2004 

Porsche 987.1 Boxster 2.7L MKI 2005>>2008
Porsche 987.1 Boxster S 3.2L MKI 2005
Porsche 987.1 Boxster S 3.4L MKI 2006>>2008

Porsche 987.1 Cayman 2.7L MKI 2005>>2008 
Porsche 987.1 Cayman S 3.4L MKI 2006>>2008

Porsche 996 Carrera 3.4L 2001
Porsche 996 Carrera 4 3.4L 2001
Porsche 996 Carrera 3.6L 2002>>2004
Porsche 996 Carrera 4 3.6L 2002>>2004
Porsche 996 Carrera 4S 3.6L 2002>>2005 
Porsche 996 Targa 3.6L 2002>>2005

Porsche 997.1 Carrera 3.6L MKI 2005>>2008
Porsche 997.1 Carrera S 3.8L MKI 2005>>2008
Porsche 997.1 Carrera 4 3.6L MKI 2006>>2008
Porsche 997.1 Carrera 4S 3.8L MKI 2006>>2008
Porsche 997.1 Targa 4 3.6L MKI 2007>>2008
Porsche 997.1 Targa 4S 3.8L MKI 2007>>2008

NOTE: For The 2001 Model Year, Porsche Replaced The Intermediate Shaft's Roller-Type (Duplex) Chain With A Tooth-Type Chain. This Listing Is For The Later Tooth-Type Chain And Is Not Compatible With Earlier Engines Equipped With The Roller-Type Chain.

While Unlikely, It's Possible That An Earlier Engine May Have Been Rebuilt And Upgraded To Use The Newer Chain Design. For This Reason, Design 911 Strongly Recommends Confirming Which Type Of Chain Your Engine Uses Before Placing An Order. To Assist With Identification, Our Product Images Include A Helpful Comparison Between The Roller-Type (Duplex) Chain And The Tooth-Type Chain.

Diagram Ref No 17  

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99610517158

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Tooth-type timing chain used to connect the engine’s crankshaft to the intermediate shaft (IMS).

Fits:
Porsche 986 Boxster 2.7L 2001-04
Porsche 986 Boxster S 3.2L 2001-04 

Porsche 987-1 Boxster 2.7L 2005-08
Porsche 987-1 Boxster S 3.2L 2005
Porsche 987-1 Boxster S 3.4L 2006-08

Porsche 987-1 Cayman 2.7L 2005-08 
Porsche 987-1 Cayman S 3.4L 2006-08

Porsche 996-1 Carrera 3.4L 2001
Porsche 996-1 Carrera 4 3.4L 2001

Porsche 996-2 Carrera 3.6L 2002-04
Porsche 996-2 Carrera 4 3.6L 2002-04
Porsche 996-2 Carrera 4S 3.6L 2002-05 
Porsche 996-2 Targa 3.6L 2002-05

Porsche 997-1 Carrera 3.6L 2005-08
Porsche 997-1 Carrera S 3.8L 2005-08
Porsche 997-1 Carrera 4 3.6L 2006-08
Porsche 997-1 Carrera 4S 3.8L 2006-08
Porsche 997-1 Targa 4 3.6L 2007-08
Porsche 997-1 Targa 4S 3.8L 2007-08

NOTE: For the 2001 model year, Porsche replaced the intermediate shaft's roller-type (duplex) chain with a tooth-type chain. This listing is for the later tooth-type chain and is not compatible with earlier engines equipped with the roller-type chain.

While unlikely, it's possible that an earlier engine may have been rebuilt and upgraded to use the newer chain design. For this reason, Design 911 strongly recommends confirming which type of chain your engine uses before placing an order. To assist with identification, our product images include a helpful comparison between the roller-type (duplex) chain and the tooth-type chain.

Diagram ref. 17.  

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99610517158

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