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302 rear main seal

Discussion in 'Ford Trucks' started by NoSnow, Jun 29, 2003.

  1. NoSnow

    NoSnow Member
    Messages: 32

    I have an oil leak on rear main of my 81-302. F-150,4X4, manual, if it matters. My Haynes manual doesn't cover this part.
    How big of a job is this, I put a clutch release bearing in last year and hopping I don't have to pull trans again.
    Anyway, would someone be willing to post the instructions from their manual?
    Bob
     
  2. wyldman

    wyldman Member
    Messages: 3,265

    The trans will have to come back out,and then pop off the flywheel,and the seal is right there.Just pop it out,and put a new one in.Be carefull when installing so you don't fold the seal lip over.There are special seal installers available,or you can use a band type piston ring compressor.Tighten up the band,until the seal fits over it.Loosen it off to expand the seal.Put it over the back of the crank,and tighten it down,and the seal can then be popped in,as it will be guided right over the crank.
     
  3. wyldman

    wyldman Member
    Messages: 3,265

    You may also want to spend an extra few minutes diagnosing it,as it could be coming from somewhere else.Shampoo it off well,and then run it until you see the leak.

    The back of the intake,rocker covers,and the oil pan can all look like a rear main.Make sure you narrow it down before you tear into it.
     
  4. NoSnow

    NoSnow Member
    Messages: 32

    I'm pretty sure it is rear main. Already did rocker and front cover. Looks like pan leaks a little also though not as bad.
    Got the truck for 2K and have got 6 years use with very little $ & time put into it. With the list of repairs it will be needing this year I believe the rear main is a fatal diagnosis, just not willing to pull trans again. Looks like the old beast may be having a retirement party this fall.

    Thanks for the replys
    Bob
     
  5. Pelican

    Pelican 2000 Club Member
    Messages: 2,075

    Chris, is that a 1 piece seal there? My '81 F-350 with 351 had a 2 piece seal that I was able to replace by dropping the pan.
     
  6. Arc Burn

    Arc Burn PlowSite.com Addict
    Messages: 1,139

    Good question Pelican,I did some work on an older Chevy(i realize we are talkin fords)and was surprised to see a 2 piece seal,drop the pan like you said and your in business.
     
  7. wyldman

    wyldman Member
    Messages: 3,265

    You guys are right.The 81's had two piece rear mains,which only require pan removal.

    In mid year 82 or so,they switched to the one piece style.

    I actually wrote my original post thinking it was a 91,not an 81.Sorry for the confusion.Don't see too many 1981 plow trucks around anymore.

    So you only have to drop the oil pan,and the trans can stay in the truck.Pull the rear main cap,and install the new two piece seal.
     
  8. NoSnow

    NoSnow Member
    Messages: 32

    Well maybe I'll take a shot a it then. Could use pan gasket anyway.
    BTW- not a plow truck, just a tool hauler for landscaping.
     
  9. Pelican

    Pelican 2000 Club Member
    Messages: 2,075

    You'll need to loosen the motor mounts and jack the motor by the crank pulley. Next allow the pan to drop onto the front axle and rest there. Remove the oil pump bolts and allow the pump to drop into the pan. With a bunch of wiggling, you can slide the pan out to the rear of the truck.

    Pull the rear bearing cap, push out old seal, oil new seal and slide into place. Retorque bearing cap.

    Lay the oil pump in the bottom of the pan in the right orientation for mounting, wiggle and slide pan into place and rest on axle. Install oil pump, and then the pan gaskets. Reinstall pan. Lower engine, tighten motor mounts.

    Good luck!