Ford Super Duty 4R100 Transmission - Photos

10. These are three different converter clutch materials found in the 4R100 transmission. The one on the outside is a competitor's brand. The one in the middle is the stock clutch material. The one on the inside is what Wood uses in all his rebuilds. Notice how thick the disc and outer engagement teeth are. This increase in thickness, as well as tooth count, adds strength and helps Wood's transmissions stand up to higher torque loads.
10. These are three different converter clutch materials found in the 4R100 transmission.
11. Here again are the three converter clutch materials. Notice the difference in color between the Wood unit and the other two. The reason for this is that the Wood clutch is made from a special high-energy material that is super-expensive and long-lasting.
11. Here again are the three converter clutch materials. Notice the difference in color be
12. This picture shows the inside of the torque converter Wood installs with each high-performance transmission. This torque converter features furnace-brazed fins and bearings throughout to increase durability.
12. This picture shows the inside of the torque converter Wood installs with each high-per

13. Here you can see the difference between a stock torque converter and the Wood unit. The front cover of the Wood unit is a billet-machined piece. This prevents converter housing flex, as well as eliminates the possibility of the converter separating from the flexplate.
13. Here you can see the difference between a stock torque converter and the Wood unit. Th
14. Wood replaced each and every high-wear washer (front) with high-quality Torrington bearings (rear). This reduces transmission drag and easily doubles the service life of the parts.
14. Wood replaced each and every high-wear washer (front) with high-quality Torrington bea
15. Shown here are just a few of the internal clutches Wood replaces during the rebuild process. He only uses factory-type materials because when properly lubricated, these clutches almost always outlast any other aftermarket-type materials. We couldn't give away any secrets, but Wood told us that each and every clutch cluster receives additional friction materials.
15. Shown here are just a few of the internal clutches Wood replaces during the rebuild pr

16. This is just one of many billet-shaft upgrade options Wood offers his customers. This one happens to be a 300M input shaft for the 4R100; in addition, he also offers intermediate and output shafts that are each load-tested to 2,200 lb-ft of torque. These are only necessary for drag racing, sled pulling, and other extreme applications.
16. This is just one of many billet-shaft upgrade options Wood offers his customers. This
17. The 4R100's center support (shown) is the most common culprit when it comes to transmission failure. For this reason, Wood spends a lot of time machining down this aluminum part so that a steel snap ring can be installed in front of it. The steel then becomes the wear surface instead of the aluminum. We don't expect you to visualize this unless you've seen the inside of a 4R100; just know that this simple step is one of many machining processes each Wood transmission undergoes.
17. The 4R100's center support (shown) is the most common culprit when it comes to transmi
18. After reassembly, Wood replaced the '99 OE transmission cooler found under our donor's truck with the improved type found on newer 6.0L trucks. As you can see, the difference in surface area is obvious; this resulted in a 30-degree temperature drop verses the smaller unit's 15. This upgrade is nice because it bolts on easily in the same location, and uses genuine factory Ford parts.
18. After reassembly, Wood replaced the '99 OE transmission cooler found under our donor's

19. Each and every transmission Wood rebuilds also receives a brand-new factory Ford radiator. This is always necessary because, once contaminated with clutch material, it's almost impossible to get the same efficiency from the built-in transmission cooler. In the case of '99 trucks, Ford didn't include a built-in transmission cooler with the radiator. This is part of the reason why they had that silly bypass circuit with the check valve shown earlier. In '00-and-later trucks, they improved this design and included a separate circuit for ATF temperature regulation at the bottom of each radiator. This design helps bring the ATF up to normal operating temperature at initial start-up. It also helps cool the ATF under extreme conditions.

Another service John Wood offers his customers is custom ECU tuning via SCT's performance interface and computer software. We had him tune our donor's truck for improved power and higher top speed, as well as speedometer calibration settings for 40-inch tires. In addition, this software can take out power for improved reliability in fleet trucks or set a speed governor for teenage drivers. Our donor really liked the performance gains this retune provided for his truck. In fact, it worked so well, he decided to get rid of the plug-in tuner that caused his troubles in the first place. After over 1 1/2 years and nearly 29,000 miles on the Wood-prepped transmission, our donor is very happy and still enjoying his Super Duty's newfound reliability and performance. The cost of this rebuild was not inexpensive, but considering what you get for the money, we feel it's one of the best programs available for the 7.3L Super Duty owner.

For those of you who don't need to spend a fortune on transmission performance like our donor did, but still want to tow reliably with up to 350 hp, Wood has an option for you too. This year, he came out with a new rebuild program where he guarantees his work for 75,000 miles or three years, whichever comes first. This program was designed for the average Joe who simply has an intake, exhaust system, and/or a programmer. The price for the Towmaster rebuild is $3,600-not bad, considering the average dealership rebuild is around $3,800.