1. Introduction
This instruction manual provides essential information for the JEGS Complete Transmission Rebuild Kit, designed for 1969-1986 GM or Chevy TH-350 automatic transmissions. This kit is specifically for non-lockup models with a 30-spline input shaft. It contains a comprehensive set of components required for a thorough transmission overhaul, aiming to restore optimal performance and extend the life of your transmission.
Proper installation and adherence to established automotive repair practices are crucial for the successful operation of the rebuilt transmission. If you are not experienced in transmission repair, professional assistance is highly recommended.
2. Kit Contents
The JEGS Complete Transmission Rebuild Kit includes the following components:
- High-Energy Clutches & Band
- Steel Clutch Plates
- All paper gaskets
- Pan gasket
- Rubber O-rings
- Rubber lip seals
- Metal clad seals
- Sealing rings
- Thrust washer kit
- Filter
- Front & rear bushings
- Modulator
3. Installation and Setup
3.1 Safety Precautions
- Always wear appropriate personal protective equipment (PPE), including safety glasses and gloves.
- Ensure the vehicle is securely supported on jack stands or a lift before working underneath.
- Disconnect the vehicle's battery before beginning work.
- Work in a well-ventilated area.
- Transmission fluid can be hot; allow the transmission to cool before draining.
3.2 General Installation Steps
The following steps outline a general procedure for rebuilding a TH-350 transmission. Refer to a comprehensive service manual for your specific vehicle and transmission model for detailed, step-by-step instructions, torque specifications, and diagnostic procedures.
- Transmission Removal: Safely remove the transmission from the vehicle. Drain all fluid and disconnect all linkages, electrical connections, and cooler lines.
- Disassembly: Disassemble the transmission carefully, keeping all components organized. Document the order of removal and orientation of parts, especially clutch packs and planetary gears. Inspect all hard parts for wear or damage.
- Cleaning and Inspection: Thoroughly clean all reusable components. Inspect the transmission case, valve body, drums, shafts, and gears for cracks, scoring, or excessive wear. Replace any damaged hard parts not included in this kit.
- Component Replacement: Replace all gaskets, O-rings, lip seals, metal clad seals, and sealing rings with the new components from the JEGS kit. Install the new high-energy clutches, steel plates, and band. Replace the front and rear bushings, filter, and modulator. Ensure all thrust washers are correctly installed.
- Reassembly: Reassemble the transmission in the reverse order of disassembly, paying close attention to proper clearances and torque specifications. Lubricate all moving parts with clean transmission fluid during assembly.
- Transmission Installation: Reinstall the rebuilt transmission into the vehicle. Reconnect all linkages, electrical connections, and cooler lines. Ensure all bolts are torqued to factory specifications.
- Fluid Fill: Fill the transmission with the recommended type and amount of new transmission fluid.
4. Operating (Post-Rebuild)
4.1 Initial Startup and Checks
- After filling with fluid, start the engine and allow it to idle. Cycle the shifter through all gear positions (P, R, N, D, 2, 1) several times, pausing in each gear.
- Recheck the fluid level with the engine running and the transmission in Park or Neutral (refer to your vehicle's service manual for the correct procedure). Add fluid as necessary until the correct level is reached.
- Inspect for any leaks around the transmission case, pan, and cooler lines.
4.2 Break-in Procedure
A proper break-in period is important for new clutch and band materials. Drive the vehicle gently for the first 500 miles, avoiding hard acceleration, heavy towing, or aggressive driving. This allows the new components to seat properly and ensures optimal performance and longevity.
5. Maintenance
Regular maintenance is essential for the continued reliable operation of your rebuilt transmission.
- Fluid and Filter Changes: Adhere to your vehicle manufacturer's recommended schedule for transmission fluid and filter changes. Use only the specified type of transmission fluid.
- Leak Inspection: Periodically inspect the transmission for any signs of fluid leaks. Address any leaks promptly to prevent fluid loss and potential damage.
- Cooling System: Ensure the transmission cooling system is functioning correctly to prevent overheating, which can severely damage transmission components.
6. Troubleshooting
If you encounter issues after rebuilding your transmission, consider the following common problems and potential causes:
| Symptom | Possible Cause |
|---|---|
| Fluid Leaks | Improperly seated gaskets or seals, damaged pan, loose bolts, incorrect torque. |
| No Engagement / Delayed Engagement | Low fluid level, incorrect band adjustment, valve body issues, internal assembly error. |
| Harsh Shifting / Slipping | Low fluid level, incorrect band adjustment, worn clutch plates (if not replaced correctly), modulator issue, valve body malfunction. |
| Overheating | Low fluid level, restricted cooler lines, faulty torque converter, internal friction. |
For persistent or complex issues, it is strongly recommended to consult a qualified transmission specialist or refer to a detailed service manual for diagnostic procedures.
7. Specifications
- Brand: JEGS
- Model Number: 62102
- OEM Part Number: 62102
- Compatibility: 1969-1986 GM/Chevy TH-350 (non-lockup) with 30-spline input shaft
- Item Weight: 9.4 pounds
- Product Dimensions: 23 x 15.5 x 4.2 inches
- Country of Origin: Made in USA
8. Warranty and Support
For specific warranty information regarding your JEGS Complete Transmission Rebuild Kit, please refer to the documentation included with your purchase or contact JEGS directly. For technical support or inquiries, please visit the official JEGS website or contact their customer service department.
You can find more information and contact details on the JEGS Store Page.