The Telma AC50-55 is an electromagnetic retarder designed for installation on Ford E-350/450 Cutaway chassis, integrated with a Telma Control Module (TRCM). This device provides supplementary braking, enhancing vehicle safety and reducing wear on the service brakes by offering friction-free deceleration.
Function Description:
The Telma AC50-55 operates by using electromagnetic forces to create a braking torque on the driveline. When activated, typically via a foot switch integrated with the brake pedal, an electrical current is passed through coils within the retarder. This generates a magnetic field that interacts with rotating discs (rotors) connected to the driveshaft, inducing eddy currents. These eddy currents create a resistance to rotation, effectively slowing down the vehicle without mechanical friction. The braking force is proportional to the current applied to the coils, allowing for modulated deceleration. The Telma Control Module (TRCM) manages the activation and intensity of the retarder, often integrating with the vehicle's existing systems, such as the brake pedal and potentially the cruise control. A light bar display provides visual feedback to the driver regarding the retarder's power level. The system is designed to activate progressively with brake pedal application and deactivate when the pedal is released or when the vehicle comes to a complete stop. It also prevents activation if the accelerator is pressed or cruise control is engaged, ensuring safe operation.
Important Technical Specifications:
The manual provides detailed technical data for various Ford E-350/450 Cutaway configurations, including different wheelbases (138.0", 158.0", 176.0", 186.0", 190.0", 208.0"), engine types (5.4L, 6.0L/6.8L), transmission models (FORD 5R110), axle makes (DANA 70/70HD), and drive types (4X2).
The retarder model is AC50-55, with part number CN201155.
Key components of the installation kit (TIK10677) include:
- Retarder Unit: AC50-55 / 12V (1410-1550)
- Brackets: Left Side Retarder Bracket (4.5 Degree) TIB03123, Right Side Retarder Bracket (4.5 Degree) TIB03124, Ford E350-450 Chassis Bracket TIB03127. These brackets are crucial for mounting the retarder to the chassis frame rails.
- Mounts: Telma Shock Mount Set (30 Shore) JZ1007XX-30, which includes rubber mounts to absorb vibrations.
- Fasteners: Various bolts (9/16"-12 UNC, 1/4"-28 UNF, 5/16"-18 UNC, 1/2"-13 UNC, M14, M16x1.5x100mm), nuts (9/16"-12 UNC, 3/8"-16 UNC, 1/4"-28 UNF, 5/16"), lock washers (9/16", 1/4" split, 3/8" split, 5/16" split, 1/2" med split), all-metal locknuts (1/2"-20UNF, M16-2.0), and fender washers. Specific torque values are provided for these fasteners, such as 150 lb-ft (±10%) for 9/16" bolts, 65 lb-ft (±10%) for M14 bolts, 17 lb-ft (±10%) for 5/16" bolts, and 75 lb-ft (±10%) for 1/2" bolts.
- Control System Components: Harness W/ JD331121 TID11050, Control / Relay Box Bracket TIB01017, Telma Control Module Ford CAN TIG31063, Ford E350-450 Pedal Clamp TIB05002, Ford E350-450 Foot Switch Bracket TIB05046, Ford E350-450 Pedal Bracket TIB05047, Foot Switch JC120102, Telma Light Bar Display TIG11010, Music Wire / Return Spring TIF05021.
- Driveshaft Information: The system requires a slip assembly on each side of the Telma. U-joints should be SPICER part number SPL36-1X (1410). Flange yokes (Spicer part number 3-2-429) are also specified. Driveshaft lengths and angles are critical and must conform to Ford QVM guidelines and Spicer recommendations. Shaft lengths over 50" should use 4" tubing. Minimum tube diameter and thickness are specified (e.g., 2.50" diameter, 0.083" thickness for some configurations, 3.00" diameter, 0.083" thickness for others, and 4.00" diameter, 0.083" thickness for longer shafts). Angle tolerance is ±0.2°, and dimension tolerance is ±1/16".
- Electrical System: The battery pack must consist of two batteries connected in parallel, equivalent to diesel OEM capacity. Power and ground cables (4AWG and 10G) are specified.
- Vehicle Speed: Maximum allowed vehicle speed is 80mph or 89mph depending on the specific configuration.
Usage Features:
- Integrated Control: The Telma Control Module (TRCM) integrates with the vehicle's brake pedal via a foot control switch, providing progressive retarder activation.
- Driver Feedback: A light bar display in the dash provides visual indication of the retarder's power level (4 stages).
- Safety Interlocks: The system is designed to prevent activation when the accelerator is pressed or cruise control is engaged, ensuring safe operation. It also turns off when the brake pedal is released or when the vehicle comes to a complete stop.
- Reduced Brake Wear: By utilizing electromagnetic braking, the Telma retarder significantly reduces the reliance on the vehicle's friction brakes, extending their lifespan and reducing maintenance costs.
- Enhanced Control: Provides additional braking power, especially beneficial for heavy vehicles or those operating on long descents, offering better control and stability.
Maintenance Features:
- Installation Checklist: A comprehensive "Post Install Checklist" (Section 6) is provided to ensure proper installation and functionality. This checklist covers physical checks (batteries, Telma cables, relay box, Telma unit, control module, foot switch, indicator lights), general wiring, control harness, power harness, drive shafts, and operational checks (road test).
- Vent Tube Extension: A plastic vent tube extension is installed on the grease chamber vent tube to prevent crimping and restriction, ensuring proper ventilation of the retarder.
- Corrosion Protection: Terminals and connections for power and ground cables should be coated with anti-corrosion paint or body undercoat after installation to protect against environmental elements.
- Harness Routing: All wiring harnesses (power and control) must be secured with rubber-coated cable clamps and routed away from heat sources (exhaust system components) and moving parts (rotors) to prevent damage. Minimum clearances (e.g., 4 inches from rotors, 6 inches from exhaust) are specified.
- Drive Shaft Verification: Critical dimensions and angles of the driveshafts must be measured and verified against the installation drawings using an electronic anglemeter (0.1 degree accuracy) to ensure proper driveline angularity and prevent vibrations or damage.
- Dynamic Balancing: All drive shafts must be dynamically balanced after modification to prevent vibrations.
- Foot Switch Adjustment: The plunger-type foot switch requires careful adjustment to ensure proper activation within the brake pedal's free play, with a specified 1/8" gap when the pedal is in its highest position.
- Telma Control Module Configuration: After wiring installation, a PC connection is required to configure the Telma Control Module (TRCM) and check for proper function. Power cycling the module (by unplugging and reconnecting the gray connector) is necessary after configuration changes.
- Axle Shim Installation: Some configurations may require axle shims (not included in the kit) to adjust the axle angle, following Ford guidelines for proper shim type and procedure. This involves loosening u-bolt nuts, lifting the chassis, sliding the shim over the centering pin, and re-tightening.
- Exhaust Modification: For some wheelbases (e.g., E350 138"), a shorter replacement muffler may be necessary.
Need help?
General
To Next Page