In our last issue, we had Remac Transmissions, in San Dimas, California, go through a Ford 4R100 auto trans to make it better than new.  This time, we will be installing that beefed-up trans so that our F-250 shop truck will be able to safely perform a multitude of tasks, from moving parts to towing trailers of all sizes.  However, before that can happen, the better than new automatic needs to be installed. 

While installing an automatic transmission may seem a simple task, each vehicle and transmission type has some unique aspects to consider. For example, this installation will take place in a 4×4 with a transfer case. If you have a high-milage truck, be sure to have the T-case inspected and if needed, have it refreshed too. We’ll cover the basics for our vehicle, and provide a few tips and tricks along the way. This should help you if you decide to do a 4R100 replacement on your own Super Duty. DW

1 While Remac ships its transmission with a torque converter that is prefilled with EOM spec transmission fluid, it is best to check it before installation to be sure it is topped off.

2 The basic transmission will need to be bolted to the transfer case for our 4×4 Ford.

3 The 7.3L Power Stoke, like most engines, has freeze plugs at the back of the block. They should be inspected and replaced if needed. Brass is preferable to steel for the freeze plugs. They won’t rust out over time and hold better than steel, due to the greater differential in thermal expansion with the cast iron block.

4 Ford used two different starters for the 7.3L engines. Early models used a standard starter and matching adapter. Seen here is the early model (1994-2000) version. The starter adapter ring will need to be changed to use the later model high-torque unit. While this 2002 originally had the high-torque starter and adapter ring, it was swapped out sometime in this truck’s history. Either setup will work on the 7.3L Power Stoke engines. (Note the 1985-94 6.9L and 7.3L IDI units are different)

5 The flex plate is bolted to the ended of the crankshaft flange, after the starter adapter ring is installed.

6 Flushing the transmission lines and transmission oil cooler is recommended, before the new transmission is installed.

7 A tip for doing the transmission installation yourself: The fuel pump on the frame is easier to access with the transmission out. If your truck is a high miler, you might want to replace this pump now for added insurance down the road.

8 The transfer case should be bolted to the transmission while it’s outside of the truck. It is simpler to do this now than when installed in the truck with the floorboard in the way.

9 The torque converter, after checking that it is full of fluid, is installed on the transmission input shaft. Look closely and you’ll also see that the front driveshaft is bolted to the T-case, before installing the unit in the truck. This is said to be easier than bolting to the front output while in the truck.

10 The transmission and transfer case assembly is lifted into the truck with the aid of a transmission jack. The unit is bolted onto the motor and the front driveshaft is bolted to the front differential yoke.

11 The transmission mount is bolted to the back of the 4R100 transmission. This mount is then tightened to the rear transmission cross member.

12 Always be sure to reinstall the dust shield at the bottom of the bell housing.

13 The rear driveshaft is a two-piece unit with a center support bearing. Ours was well used and in need of repair. It was replaced will an all-new unit from J.E. Reel, which is better than stock.

14 If your truck has had the automatic transmission fail catastrophically, a new oil cooler is recommended. This and flushing the hard lines will keep metal shavings from the old system from contaminating your new setup. Here you see a larger transmission oil cooler from a 6.0L Ford being installed. (The June 2015 issue of Diesel World has more on this upgrade.)

15 The transmission must be filled with 10 quarts of the correct type of automatic transmission fluid and then rechecked and topped off after starting the engine and putting the transmission in gear a few times to circulate the fluid throughout the system.

16 With the new Remac automatic transmission in place, a test drive had to be conducted. The unit performed flawlessly and should last longer than the stock unit.

Domestic Diesel

J. E. Real Driveline

Remac Transmissions