Product Description
A4688 – TRANSMISSION SLAVE VALVE (1/8" NPT PORTS)
PART NUMBER(S):
Fleet Products: A4688-G | OE: A4688, A-3991 | Automann: 174.4688
DESCRIPTION:
Model: Transmission Slave Valve
Vehicles: Fuller 6613, 9513, 12510, 12513, 12515, 14909, Mack, Navistar, Freightliner, and other heavy-duty trucks
• Valve Type: Slave valve for manual transmission systems
• Function: Regulates air flow for transmission shifting (range/slave function)
• Port Configuration:
• Two 1/8" NPT supply ports
• Two 1/8" NPT delivery ports
• One 1/8" NPT control port
• One 1/8" NPT exhaust port
• Port Thread Type: NPT
• Port Thread Diameter: 0.125"
• Mounting: Inline, transmission-mounted
• Material: Heavy-duty metal construction
• Includes: Mounting gasket
• System Integrity: Direct replacement for listed OEM and aftermarket part numbers
• Performance/Technology: Plug-and-play with existing air control systems; supports precise air modulation during gear shifts
• Compatibility: Eaton Fuller, Mack, Navistar, Freightliner, and other heavy-duty truck transmissions
Applications:
Used in air-actuated manual transmission systems to control range selection. Engineered for long service life in demanding fleet environments. Ensures accurate shifting in Fuller-style transmissions requiring slave valve actuation.
CROSS-REFERENCE(S):
A4688, A-4688, A4688NP, A4688P, A4688G, A3991, A-3991, A3991X, FUL A4688, FUL A3991, FULA4688, FULA3991, 3088-A4688, 3088-A-4688, 3088A4688, 3088-A3991, 422-159-C, 422159C, 422159C91, 422159C92, 0587-A4688, DMA4688, EF36770, GSV-3677, 3676, 3677, 36770, M13A4688, 14612, TRV4688, WAF237, S-3291, S3291, FUR-A-4688, VTC-2913, SM-3780, KA4688, A4688P, 1738352B, 35530409, 6WA4688, 48A4688P, A4688G
A cross-reference listing means this part may be a compatible replacement for these part numbers based on OEM or distributor data.
IMPORTANT INSTALLATION NOTES:
✔ All ports are 1/8"-27 NPT – verify port cleanliness before installation
✔ Use supplied gasket for secure inline mounting
✔ Install in transmission-mounted position; secure to avoid vibration fatigue
✔ Directly compatible with Fuller-type range shift air circuits
✔ Replace immediately if leaking, sticking, or failing to actuate
SOLD AS NEW
Brand new and ready to install, with OEM Grade Reliability
SUPPORT & ORDERING
For technical support, installation guidance, or to confirm fitment, Call: 1-877-243-0442 | Email: sales@fleet-products.com
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