4R100 Master Rebuild Kit 1998, new and ready to install. Fits the 4R100. Ships fast from the USA.
The 1998 model year is the first year Ford built the 4R100, and it is also the year that causes the most ordering mistakes. If your 1998 heavy-duty Ford truck or E-Series van slips between gears when it is warm, has lost overdrive, or drained black fluid with clutch lining on the magnet, you are looking at an overhaul, and this 4R100 master rebuild kit is built for that first-year unit. It is new, carries Raybestos frictions, and is pictured with the friction and steel packs, band, filter, gaskets and the full seal set.
Ford took the E4OD case and gearset for 1998 and changed the parts that failed: a common F81P pump casting, a stamped-steel coast clutch drum with wider-tooth steels in place of the cast-iron E4OD drum, and a PTO option. The clutch packs, seals and gaskets still do the same job. Each pack is applied by a piston sealed with rubber, and each friction relies on lining that has not been cooked. Raybestos is a long-time friction supplier to the rebuild trade, and a master kit renews every pack and seal at once so the first-year unit leaves the bench evenly fresh instead of half new and half worn.
Check that the problem is inside the case. Look at the connector, pull codes and run a line pressure test so a wiring or EPC fault is not mistaken for burnt clutches. Then confirm what is on the bench, because in 1998 the E4OD was still in some trucks. A 4R100 case has a PTO port and an E4OD case does not, and Transmission Digest notes the stator support orientation tells an E4OD pump from a 4R100 pump. Our 4R100 vs E4OD identification guide shows both checks, and the E4OD and 4R100 wear points guide covers what to inspect once it is apart.
This kit is listed for the 1998 4R100 only. First-year coast clutch drums came in two forms: the non-PTO drum YC3Z-7G387AA with two frictions on a bushing, and the PTO drum YC3Z-7G387BA with three frictions on a bearing. A later revised drum may have been installed in a previous repair, so count the coast clutch plates in your unit. If your 1998 truck turns out to have an E4OD, use the E4OD/4R100 parts page to find the E4OD kit for that year. For later units, the 1998-2005 4R100 kit is the better match. When in doubt, send us your year and VIN.
Clean every part, then inspect the pump body and gears, the drums and the bushings before any new part goes in. Sonnax's vacuum test guide notes the 1996-1998 E4OD valve body tests at the same locations as the non-PTO 4R100, which helps when you test the 1998 valve body. If the pump is scored, replace it with a 4R100 pump for 1998-2004, and if the overdrive planet is blued, swap in a 1998 4R100 planetary. Fit a locking spiral retaining ring behind the OD piston return spring, soak frictions in MERCON V before assembly, set clutch pack clearances, and prime the pump. Flush the cooler, install a rebuilt converter, then check the fluid level hot in Park.
| Fits | 4R100 1998 |
| Part type | Master Rebuild Kit |
| Condition | New |
| Brand | Raybestos |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Look for a PTO port on the case; a 4R100 has one and an E4OD does not. The coast clutch drum is also stamped steel on a 4R100 and cast iron on an E4OD.
The listing specifies Raybestos frictions. The kit is pictured with frictions, steels, band, filter, gaskets and seals.
It is listed for 1998. Later units can have revised coast clutch drums and other running changes, so the 1998-2005 kit is the better match for those years.
Any worn hard parts found at teardown, typically pump parts, bushings or a heat-damaged planetary, plus a locking OD retaining ring and a rebuilt torque converter.
MERCON V. Set the final level hot with the engine running in Park.
