75906

The gasket associated with part number 75906 is produced in silicone rubber and is offered under manufacturer designations RG-75906-SP and APS-75906-S for Lycoming valve cover or rocker box cover locations. The silicone construction is formulated for lubricating oil resistance, low compression set, and extended flexibility to support reuse in service. One implementation uses aerospace mechanical grade AMS silicone material with a thickness of 1/8 inch and incorporates six bolt holes for attachment. The gasket is approved under FAA-PMA for use in certified aircraft in the Real Gaskets configuration.

Supported Lycoming engine series documented for this configuration include O-235, O-290, O-320, IO-320, AIO-320-B and -C, LIO-320-B and -C, AEIO-320-E1B and -E2B, O-340, O-360 including A, B, C, and D series, IO-360 including B series, HO-360-A and -B, HIO-360-B, LO-360, LIO-360 including B1G6, VO-360 and IVO-360 including A1A, TO-360 and LTO-360 76 series, O-480, O-540, IO-540 including C, D, J, N, and R series, AEIO-540-D series, and TIO-540 variants including -AF1A, -AF1B, -AG1A, -AK1A, -AA1AD, -AB1AD, -C1A, -E1A, -G1A, and -H1A series. The gasket is described as reusable and suitable for installation in a dry condition. Published installation guidance specifies cleaning old material from the valve cover and cylinder surfaces, installing the RG-75906-SP gasket dry, torquing the cover bolts to 25 in-lb, and after engine run-up or first flight checking and adjusting cover bolt torque to 20 in-lb. Documented corresponding or equivalent references for this gasket include part numbers 75906-SP, 06B26669, SLR75906, and AEL75906.

Dimensional and logistics data for silicone valve cover gaskets of this style include a listed thickness of 1/8 inch, six mounting holes, approximate pack dimensions of 6 by 6 by 0.2 inches, and a nominal unit weight of 0.01 pounds.

• Silicone valve cover or rocker box gasket for Lycoming engines
• Produced under manufacturer designations RG-75906-SP and APS-75906-S
• Constructed from silicone rubber with resistance to lubricating oil and low compression set
• Uses aerospace mechanical grade AMS silicone rated to withstand temperatures up to 400 °F
• Gasket thickness of approximately 1/8 inch with six bolt holes
• Reusable design that remains flexible over a wide temperature range from -85 °F to +401 °F in APS configuration
• Approved under FAA-PMA for the Real Gaskets implementation
• Intended for dry installation between the valve cover and cylinder head sealing surfaces
• Installation torque guidance of 25 in-lb initial and 20 in-lb after engine run-up or first flight for RG-75906-SP
• Supported Lycoming engine coverage including O-235, O-290, O-320, IO-320, O-340, O-360 and derivatives, IO-360, HO-360, HIO-360, LO-360, LIO-360, VO-360, IVO-360, TO-360, LTO-360, O-480, O-540, IO-540, AEIO-540-D series, and TIO-540 variants
• Associated and corresponding part numbers including 75906-SP, 06B26669, SLR75906, and AEL75906
• Approximate package dimensions of 6 in by 6 in by 0.2 in and unit weight of about 0.01 lb

Primary reference: 75906
Manufacturer model references: RG-75906-SP, APS-75906-S
Product type: Silicone valve cover or rocker box gasket
Material: Silicone rubber, aerospace mechanical grade AMS silicone in Real Gaskets configuration
Thickness: 1/8 in
Bolt holes: Six
Temperature range (APS silicone rocker gasket): -85 °F to +401 °F
Oil resistance: Formulated for lubricating oil resistance and low compression set
Approvals: FAA-PMA approved for RG-75906-SP gasket
Supported Lycoming engines (Real Gaskets configuration): O-235; O-290; O-320; IO-320; AIO-320-B,-C; LIO-320-B,-C; AEIO-320-E1B,-E2B; O-340; O-360-A,B,C,D; IO-360-B; HO-360-A,B; HIO-360-B; LO-360; LIO-360-B1G6; VO-360; IVO-360-A1A; TO-360 76 series; LTO-360 76 series; O-480; O-540; IO-540-C,D,J,N,R; AEIO-540-D series; TIO-540 -AF1A,-AF1B,-AG1A,-AK1A,-AA1AD,-AB1AD,-C1A,-E1A,-G1A,-H1A series
Dimensions (APS configuration): 6 in x 6 in x 0.2 in
Approximate unit weight: 0.01 lb
Corresponding or equivalent part numbers: 75906-SP, 06B26669, SLR75906, AEL75906
Product category: Valve cover or rocker box gasket for Lycoming engines