Rear main seal replacement

DEREKW

MEMBER
1987 FORD F-250
7.5L
V8
4WD
AUTOMATIC
101,000 MILES

So I have the truck listed above which has a problem with the rear main seal. I really don't want to take it to an auto repair shop because they are charging $1,000.00. So I'm watching many videos on how to replace the seal. My main question is where the main seal is located at. Do we have to take the engine and transmission out?

Thank you!

1 Reply

ASEMASTER6371

MECHANIC
52,797 POSTS

Good afternoon,

The seal is around the crankshaft at the rear of the motor.

The hard part is getting to it. The oil pan has to be removed as well as the oil pump. It is a 2 piece seal the goes inside the rear main bearing cap.

The estimate was a good price considering it takes about 9 hours for this job. Since you have 4 wheel drive, it is difficult to get the pan down. The engine has to be unbolted off the mounts and jacked up as high as it can go.

I attached a short YouTube video on replacing the seal with the rear main cap off.

https://www.youtube.com/watch?v=WSy5hywk_ls

No the engine does not have to come out at all. It is all done in the truck.

Roy

A split lip-type crankshaft rear oil seal is provided for servicing these engines.
1. Remove the oil pan and the oil pump, if required.
2. Loosen all the crankshaft main bearing cap bolts, thereby lowering the crankshaft slightly but not to exceed 0.7938 mm (1/32 inch).

CAUTION: Use care to prevent scratching or damaging the crankshaft sealing surfaces.

3. Remove the rear crankshaft main bearing cap, and remove the crankshaft rear oil seal from the rear crankshaft main bearing cap and cylinder block. On the cylinder block half of the crankshaft rear oil seal use a seal removal tool, or install a small metal screw in one end of the crankshaft rear oil seal, and PULL on the screw to remove the crankshaft rear oil seal.

V8 ENGINES
On some models, the oil pump must be removed when removing the oil pan. These models are indicated in the ``Oil Pan, Replace'' procedures.
1. Remove oil pan as previously described.
2. Remove oil pump attaching bolts and the oil pump.
3. To install, prime pump with engine oil and apply sealant to gasket.
4. Insert distributor intermediate shaft, making sure that it is properly seated, then install oil pump. Do not force pump into place if it will not readily seat, as the intermediate shaft may be misaligned with distributor shaft. To align, rotate intermediate shaft until pump can be seated without applying force.
5. Install oil pan.

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