Table of Contents
Many people have expressed interest in how to build a 4R100 transmission to handle over 1000hp. This build will see 4WD launches, drag racing, towing, and daily driving. Below is a detailed guide on the entire process, covering part identification, specifications, assembly, aftermarket upgrades, and custom solutions to address common issues.
Note: This guide of 4R100 transmission does not cover disassembly, but it will cover as much as possible.
Key Components and Modifications
Torque Converter
For the torque converter, I chose Precision Industries converters, known for their full billet construction and no core charge. They are made fresh in-house. Before assembly, ensure everything is lubricated with transmission grease.
Input Shafts
There are three main input shafts for 4R100 transmission on the market. I opted for an Aermet shaft due to its superior strength, though a 300M shaft is suitable for most applications. For added durability, I incorporate an extra stress-relieving step in my process.
Pump Assembly
– Disassembly and Inspection: Carefully disassemble the pump and inspect all components for wear or damage. Ensure gears and housing are in good condition.
– Upgrades: Install billet coated pump gears with a 9-lobe design for better performance. Use alignment bands during reassembly for precise fitting.
– Valves: Replace stock valves with Sonnax and Transgo components for improved pressure regulation and clutch control.
Clutch Drum and Overdrive
Coast Clutch Drum
– Replacement: Upgrade to a stamped steel version or a PTO version with a ball bearing for enhanced durability.
– Assembly: Install the molded piston using a lip wizard to avoid seal damage. Ensure the sprag locks counter-clockwise.
Overdrive Planetary
– Billet Overdrive Planetary: Use a billet overdrive planetary for better strength, replacing the factory cast one. Reassemble gears and pins from the factory piece, ensuring the inclusion of the thrust bearing.
– Overdrive Ratio: .71:1.
– Assembly: Assemble with bearings and intermediate shaft, confirming the correct assembly by checking the locking direction of the intermediate shaft.
Overdrive Return
– Disassembly and Inspection: Ensure all check balls are free moving. Replace bonded pistons and install Sonnax spiral lock rings for better reliability.
Center Support and Intermediate Components
Center Support Sleeve
– Design: Opt for a dual load aftermarket design with aluminum plated bearings.
– Sealing Rings: Replace direct clutch sealing rings and ensure proper assembly with a snap ring to prevent movement.
– Gaskets: Use Sonnax gaskets with printed silicone around feed holes for better sealing.
Assembly
– Torque Specifications: Apply blue Loctite and torque bolts progressively to 100-120 IN.LB.
Forward and Direct Drums
Direct Drum
– Clutch Pack: Use a 5-pack drum packed with 8 Alto red clutches and Kolene steels. Replace 1-way diodes with sprags for increased durability.
– Clearances: Ensure proper clutch pack clearances using appropriate snap rings.
Forward Drum
– Billet Drum: Use a billet forward drum for added strength. Align clutches correctly and remove the wave-plate for a firmer shift feel.
Planetary Gears and Output Shaft
Rear Planetary
– Upgrades: Opt for a 6 pinion steel version and add thrust bearings for durability. Stress relieve all parts.
Low/Reverse Hub
– Reinforcement: Weld and stress relieve the hub to prevent breakage. Use 7 Alto reds on this hub.
Output Shaft
– Material: Choose a 300M output shaft for maximum strength.
Valve Bodies and Solenoids
Accumulator Body
– Valves and Springs: Use Sonnax valves and OE springs with retainer clips for shift valves. Modify the line pressure modulator to .500 for desired performance.
Main Valve Body
– Valve Kits: Combine Sonnax and Transgo kits, ensuring each valve moves freely and seals properly.
– Plate Modifications: Drill holes in the Tugger kit plate for better fluid flow.
Main Plate
– Identification: Differentiate between single notch (non-PTO) and two-notch (PTO) models.
Solenoid Body
– Identification: Identify between PWM and On/Off styles by measuring pin OHMs.
Case Preparation of 4R100 Transmission
Flatness
– Inspection: Scan for flatness using a Faro, resurfacing as needed to ensure within .0004″ accuracy. Apply fixes during assembly to prevent distortion.
Clutch Pack Applications
– Overdrive Clutch Pack: Applied in 4th only.
– Coast Clutch Pack: Applied in reverse, 3rd with TCIL lamp on (overdrive off via button on shifter) but not 3rd with TCIL lamp off and manual 1st and 2nd.
– Intermediate Clutch Pack: Applied in 2nd, 3rd, 4th, and manual 2nd.
– Direct Clutch Pack: Applied in reverse, 3rd, and 4th.
– Forward Clutch Pack: Applied in all forward gears, including manual lockout.
– Low/Reverse Clutch Pack: Applied in reverse and 1st manual but not first when shifter is in drive.
Final Tips and Recommendations
Pump Reassembly
– Alignment Band: Use a band to ensure alignment of pump gears and housing.
– Valve Assembly: Replace pressure regulator and converter regulator valves for better performance.
– Pump Gears: Opt for billet 9-lobe pump gears to enhance pressure stability.
Center Support
– Dual Load Design: Choose a dual load aftermarket design for added strength.
– Sealing Rings: Replace with new sealing rings for better performance and durability.
– Assembly Torque: Use blue Loctite and torque bolts to specified levels to prevent loosening.
Clutch Packs
– Coast Clutch Drum: Ensure proper assembly and clearance for longevity.
– Direct Drum: Replace with performance-oriented parts, ensuring proper clutch pack clearance.
– Forward Drum: Choose billet versions for strength, aligning clutches correctly.
Valve Bodies
– Accumulator Body: Install Sonnax valves for better shift control.
– Main Valve Body: Use a combination of Sonnax and Transgo kits for optimal performance.
– Solenoid Body: Ensure identification and installation of correct solenoid type for your setup.
Conclusion
This guide provides a comprehensive overview of building a high-performance 4R100 transmission, highlighting key components, upgrades, and assembly tips. While not every modification is necessary for all builds, these steps are tailored to meet specific power goals and anticipated use. Stay tuned for more updates, and feel free to share any insights or ask questions! Happy building!
Related Links
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