Brian1
Elite Explorer
- Joined
- February 2, 2000
- Messages
- 5,387
- Reaction score
- 644
- City, State
- Albuquerque, NM
- Year, Model & Trim Level
- 1991 XLT
- Callsign
- KG5BAQ
The rear main oil seal on the 4.0L OHV engines are notorious for leaking. It is claimed that the crankshaft surface is too polished and the normal oil seal lip can not retain the oil on the polished surface. I had mine replaced by a shop the last time I had my clutch replaced and it started leaking again not long after. This time, after living with the few drips every time for years, I did my own clutch job and decided to change my rear main seal again, this time the Right Way.
The info to replace the seal is found in Ford TSB 94-12-13. Here is a small how-to for replacing just the seal, you will have to get to it first by removing the trans and flywheel/flex plate which will not be covered here.
Ford TSB 94-12-13, the important install info:
Parts Needed:
Ford F5TZ-6701-A Crankshaft Oil Seal Assembly - Do not buy a normal parts store rear main seal! Use the Ford seal only! It includes a metal sleeve that presses on over the crank with a rougher sealing surface so the seal will actually seal the oil in. It runs around $50 +/- online. My local dealer wanted $75
Tools Needed:
OTC 7834 Rear Crankshaft Seal Installer for Ford ($100-$125 online)
Small drill bit and drill (1/16" to 3/32" works well)
Small slide hammer with screw attachment
Metric Allen wrench to fit OTC tool
Socket and socket wrench to fit OTC tool
Procedure:
1. Once I got to the seal I confirmed it was leaking by the oil around the area and not anywhere else. I cleaned the area with some degreaser and lightly washed it off with water and then let it dry.
2. Drill a small hole in the seal being very careful not to hit the crank or outer seal bore.
3. Screw in the screw and tip from a small slide hammer. If you don't have a slide hammer, a regular screw and a vice-grip should be a reasonable substitute.
4. Pull the seal out and clean any oil or sludge away from the area.
5. Install the OTC crank adapter
6. Lightly oil the crank and adapter surfaces
7. Place the Ford seal with sleeve as 1 unit on the adapter then place the driver over the seal and begin to tighten center bolt. Note the "steps" in the seal driver, 1 drives the metal sleeve and 1 drives the seal and keeps both aligned perfectly.
8. Tighten center bolt with hand tools only until the tool bottoms out
9. Remove the OTC tool and you are done!
Yes, the OTC installer tool is expensive but why risk pounding in a $50 seal with a makeshift tool? The sleeve is a tight fit on the crank and the tool presses it on easily in 1 piece. Well worth the cost to make sure the seal is installed without damaging it.
The info to replace the seal is found in Ford TSB 94-12-13. Here is a small how-to for replacing just the seal, you will have to get to it first by removing the trans and flywheel/flex plate which will not be covered here.
Ford TSB 94-12-13, the important install info:
Parts Needed:
Ford F5TZ-6701-A Crankshaft Oil Seal Assembly - Do not buy a normal parts store rear main seal! Use the Ford seal only! It includes a metal sleeve that presses on over the crank with a rougher sealing surface so the seal will actually seal the oil in. It runs around $50 +/- online. My local dealer wanted $75
Tools Needed:
OTC 7834 Rear Crankshaft Seal Installer for Ford ($100-$125 online)
Small drill bit and drill (1/16" to 3/32" works well)
Small slide hammer with screw attachment
Metric Allen wrench to fit OTC tool
Socket and socket wrench to fit OTC tool
Procedure:
1. Once I got to the seal I confirmed it was leaking by the oil around the area and not anywhere else. I cleaned the area with some degreaser and lightly washed it off with water and then let it dry.
2. Drill a small hole in the seal being very careful not to hit the crank or outer seal bore.
3. Screw in the screw and tip from a small slide hammer. If you don't have a slide hammer, a regular screw and a vice-grip should be a reasonable substitute.
4. Pull the seal out and clean any oil or sludge away from the area.
5. Install the OTC crank adapter
6. Lightly oil the crank and adapter surfaces
7. Place the Ford seal with sleeve as 1 unit on the adapter then place the driver over the seal and begin to tighten center bolt. Note the "steps" in the seal driver, 1 drives the metal sleeve and 1 drives the seal and keeps both aligned perfectly.
8. Tighten center bolt with hand tools only until the tool bottoms out
9. Remove the OTC tool and you are done!
Yes, the OTC installer tool is expensive but why risk pounding in a $50 seal with a makeshift tool? The sleeve is a tight fit on the crank and the tool presses it on easily in 1 piece. Well worth the cost to make sure the seal is installed without damaging it.
