1986 F-150 180,000

[quote:c6e6a7dda5="johnson69d"]I am leaking oil out of my rear main seal of my 300 straight 6 how do I go about changing the seal[/quote:c6e6a7dda5]

E-mail me for some diagrams. :)

The 300 Ltr 6 has a one piece rear seal. It can be replaced with the engine still in the truck but this requires removal of the transmission. Fords straight 6 engine is possible their best. So replacing that seal even with that sort of mileage is a good idea.

I might consider doing a compression test to ascertain the condition of the combustion chamber. If compression is good, you may want to consider removing the engine to replace the main seal. For little more work and not a lot more expense, you will be able to replace the main and rod bearings also. A worn bearing can cause seal failure. Also freshen up the oil pump. This additional work is all dependent on the overall condition of the truck, how long you will keep the truck, and how much money you wish to invest. If compression is bad consider a used engine or a rebuild of your engine.

Good luck and let us know. :)