Home / Shop / Crown Automotive Manual Transmission Synchro Blocking Rings 640397K Rings, Steel, Natural, T90, Kit

Crown Automotive Manual Transmission Synchro Blocking Rings 640397K Rings, Steel, Natural, T90, Kit

SKU: CWA640397K

Manual Transmission Synchros

Crown Automotive

Crown Automotive Manual Transmission Synchro Blocking Rings 640397K Rings, Steel, Natural, T90, Kit

SKU: CWA640397K

Manual Transmission Synchros

BACKORDER This item will be special ordered in for you. Contact us prior to purchase if you require an ETA.

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Description

Worn teeth just don't have the same bite. Crown Automotive manual transmission synchro blocking rings replace those with "dull" teeth to help restore shifting performance. Steel or brass synchronizer rings are available individually, as a set, or packaged with keys and springs. Choose the quality and value of Crown synchro blocking rings to once again enjoy grind-free shifts.

Part Type

Manual Transmission Synchros

Data: v4.2 - Upd: 2026-10-15 04:45:28

Specifications

Product Attributes - Brand: Crown Automotive
Product Attributes - Manufacturer's Part Number: 640397K
Product Attributes - Part Type: Manual Transmission Synchros
Product Attributes - Product Line: Crown Automotive Manual Transmission Synchro Blocking Rings
Product Attributes - UPC: 848399077865
Product Attributes - Synchro Material: Steel
Product Attributes - Synchro Gear Finish: Natural
Product Attributes - Quantity: Sold as a kit.
Product Attributes - Notes: Kit includes two blocking rings, three keys, and two springs.

Reference Information

Brand Name/s	Crown Automotive
StreetFX SKU	cwa640397K
SFX Item ID	5437345
Supplier Item Code	5437345
Manufacturer SKU	640397K
Manufacturer UPC	848399077865
Alternative References	T90

Compatibility

Application Data

Application Notes	Application (Fitment): 1945-1949 CJ-2A;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1945
Ending Year	1949
Make	JEEP
Model	WILLYS
Submodel	CJ-2
Engine Type	L4
Engine Size	2.2L/134
Engine Family	WILLYS L4 GAS
Engine Version	Go Devil

Application Notes	Application (Fitment): 1945-1949 CJ-2A;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1949
Ending Year	1949
Make	JEEP
Model	WILLYS
Submodel	CJ-3
Engine Type	L4
Engine Size	2.2L/134
Engine Family	WILLYS L4 GAS
Engine Version	Go Devil

Application Notes	Application (Fitment): 1953-1968 CJ-3B;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1959
Ending Year	1960
Make	JEEP
Model	CJ3
Submodel	BASE
Engine Type	L4
Engine Size	2.2L/134
Engine Family	WILLYS L4 GAS
Engine Version	Hurricane

Application Notes	Application (Fitment): 1953-1968 CJ-3B;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1960
Ending Year	1960
Make	JEEP
Model	CJ3
Submodel	BASE
Engine Type	L4
Engine Size	2.2L/134
Engine Family	WILLYS L4 GAS
Engine Version	Hurricane

Application Notes	Application (Fitment): 1953-1968 CJ-3B;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1966
Ending Year	1966
Make	JEEP
Model	CJ3
Submodel	BASE
Engine Type	L4
Engine Size	2.2L/134
Engine Family	WILLYS L4 GAS
Engine Version	Hurricane

Application Notes	Application (Fitment): 1953-1968 CJ-3B;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1966
Ending Year	1966
Make	JEEP
Model	CJ3
Submodel	BASE
Engine Type	L4
Engine Size	2.2L/134
Engine Family	WILLYS L4 GAS
Engine Version	Hurricane

Application Notes	Application (Fitment): 1953-1968 CJ-3B;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1966
Ending Year	1966
Make	JEEP
Model	CJ3
Submodel	BASE
Engine Type	V6
Engine Size	3.7L/225
Engine Family	GM V6

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1959
Ending Year	1960
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	L4
Engine Size	2.2L/134
Engine Family	WILLYS L4 GAS
Engine Version	Hurricane

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1960
Ending Year	1960
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	L4
Engine Size	2.2L/134
Engine Family	WILLYS L4 GAS
Engine Version	Hurricane

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1966
Ending Year	1966
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	L4
Engine Size	2.2L/134
Engine Family	WILLYS L4 GAS
Engine Version	Hurricane

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1966
Ending Year	1966
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	V6
Engine Size	3.7L/225
Engine Family	GM V6

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1966
Ending Year	1971
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	L4
Engine Size	2.2L/134
Engine Family	WILLYS L4 GAS
Engine Version	Hurricane

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1967
Ending Year	1967
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	V6
Engine Size	3.7L/225
Engine Family	GM V6

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1967
Ending Year	1968
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	L4
Engine Size	2.2L/134
Engine Family	WILLYS L4 GAS
Engine Version	Hurricane
Engine VIN Code	4

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1967
Ending Year	1968
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	L4
Engine Size	2.2L/134
Engine Family	WILLYS L4 GAS
Engine Version	Hurricane
Engine VIN Code	J

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1968
Ending Year	1968
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	L4
Engine Size	3.1L/192
Engine Family	Perkins diesel 4-cylinder

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1968
Ending Year	1968
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	L4
Engine Size	3.2L/3147cc
Engine Family	Perkins diesel 4-cylinder

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1968
Ending Year	1968
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	L4
Engine Size	3.2L/3147cc
Engine Family	Perkins diesel 4-cylinder

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1968
Ending Year	1968
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	V6
Engine Size	3.7L/225
Engine Family	GM V6

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1968
Ending Year	1971
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	L4
Engine Size	2.2L/134
Engine Family	Willys 4-cylinder

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1969
Ending Year	1969
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	V6
Engine Size	3.7L/225
Engine Family	GM V6

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1970
Ending Year	1970
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	L4
Engine Size	2.2L/134
Engine Family	WILLYS L4 GAS
Engine Version	Hurricane
Engine VIN Code	F

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1970
Ending Year	1970
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	V6
Engine Size	3.7L/225
Engine Family	GM V6

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1970
Ending Year	1970
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	V6
Engine Size	3.7L/225
Engine Family	GM V6

Application Notes	Application (Fitment): 1955-1971 CJ-5;Notes: w/ T90 Transmission:: Includes 2 Blocking Rings, 3 Keys, and 2 Springs;Included in Package;Axle: N/A;Transfer Case: N/A;Transmission: T90;Engine: Any
Beginning Year	1971
Ending Year	1971
Make	JEEP
Model	CJ5
Submodel	BASE
Engine Type	L4
Engine Size	2.2L/134
Engine Family	Willys 4-cylinder
Engine Version	Hurricane
Engine VIN Code	F

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Crown Automotive Manual Transmission Synchro Blocking Rings 640397K Rings, Steel, Natural, T90, Kit

Crown Automotive Manual Transmission Synchro Blocking Rings 640397K Rings, Steel, Natural, T90, Kit

Description

Part Type

Specifications

Reference Information

Compatibility

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