Hercules 4R100 Heavy Duty Transmission
Hercules 4R100 Heavy Duty Transmission
Hercules 4R100 Heavy Duty Transmission
Hercules 4R100 Heavy Duty Transmission

Hercules 4R100 Heavy Duty Transmission

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Options 4WD Include Billet Torque Converter
Product description
When you want the toughest!
  • Ultimate Duty 4R100 for the 7.3L Powerstroke
  • Designed for demanding conditions
  • Hercules Transmissions built to order - lead times average 1 week.
  • Each Unit 100% Dyno Tested – NO DOAs
  • Built in the USA
1999-2003 Ford 4R100 F250 - F550 and Excursion 7.3L Heavy Duty Diesel Transmissions:

Several years in the making.
After purchasing Factory Tech Transmissions in April of 2012, we spent the last couple years setting up the lathes and mills to cut special parts, installing blast cabinets, paint booths, and our state of the art $250,000 dynamometer powered by BlueReach Automation. We can duplicate actual driving and load conditions in a truck, including all upshifts and downshifts.


  • Designed for towing, sled pulling, and competition use.
  • Increased power transfer to the rear wheels
  • Improved shift feel
  • Clutch material designed to handle extended and elevated temperatures without burning.
  • Ultra Heavy Duty Internal Hard Parts

Standard Specifications in every Hercules transmission:

  • Direct and Forward clutches built with 120% of OEM clutch surface area.
  • Coast Clutch upgraded with 200% of OEM clutch surface area, custom spiral snap ring, and fully cut snap ring groove to hold up to exhaust brakes.
  • Overdrive built with 133% of OEM clutch surface area to hold up to towing in OD.
  • Intermediate clutches built with 133% of OEM clutch surface area.
  • Low Reverse Clutch Pack built with 133% of OEM clutch surface area.
  • Forward and Direct Clutch Packs built with 125% of OEM clutch surface area.
  • Pump modified for increased line pressure
  • Spiral snap ring over center support.
  • 45 element intermediate sprag
  • Case to center support sealed to prevent internal leakage
  • All steel planetary gears.

Center Support machined to accept case snap ring to insure the support has a solid resting surface.

Billet Forward Planet assembly.

Billet Output Shaft

The Intermediate Shaft is where we have made significant upgrades over our Heavy Duty Legendary Transmission. In the photo you can see the intermediate shaft has increased in size. The shaft has larger diameter and deeper spines. The center support hub is larger to accommodate the new shaft. The center support now uses dual bushings on the larger diameter of the shaft for greater support. 

The Billet forward clutch drum has a larger hub to accommodate the larger shaft. All this means is greater strength and more support for the center of the transmission. 

Low Reverse planet designed with Torrington bearings instead of bushings.

Metal thrust washer instead of plastic.

MagHytec Transmission Pan

Billet Aermet Input Shaft- Built for Competition Use.

Comes with our Hercules Converter. This is a multi plate "damperless" fully spined converter. It has approximately 300% increase in surface area over a standard 3 disc converter. Dual Torrington bearings. Bolts for cover instead of studs. Fits aftermarket flex plates.

  • Every single clutch pack is measured and set to exact clearances- every unit within .003"
  • Torrington bearings throughout
  • High Energy 850°frictions in all forward gears(including overdrive)- no 4R100 has ever had this. A DieselSite exclusive!
  • Full thickness steels for maximum heat transfer from clutches
  • Every re-manufactured part is run through our de-burring machine
  • New Output Speed Sensor
  • New Transmission Speed Sensor
  • New Transmission Range Sensor
  • New thermal bypass valve
  • Custom In-house built valve body for shorter shift duration - firmer shifts and longer clutch life.
  • We have a transmission hydraulic circuit pressure test machine to insure no internal leakage occurs.
  • Every Unit fully tested in our own Transmission Dynamometer - No DOA units leave here!
  • There are many more modifications we do to improve performance and reliability

Shipping based on your location. If you need lift-gate service, you will need to specify this and be aware that there is a 100.00 additional charge for this service - each time the lift gate is needed. If you need a lift gate for delivery and pick-up, the additional shipping cost will be 200.00. We will handle all the shipping arrangements getting the transmission to you in a shipping container and arrange the pick-up of your core when you are ready. So, this shipping cost is all inclusive (other than lift-gate if needed) to cover shipping to you and the shipping to get the core back to us.

Core Charge. The transmission is shipped to you in a molded shipping container. We must get this case back with your transmission core. If you send back your core without the case, you will only get $1000.00 of your core fee returned. The case has a $200.00 core fee on it. If you ordered a TC and do not send your tc core back with your transmission, there will be another $150.00 deducted.