# 1994 F250HD 351 Rear main.



## areoseek (Mar 13, 2013)

My question is not a should I fix it, It is how long can I run it.

Anyone had a rear main seal go out on a 351?
How long did you let it go, and did it get much worse?

image attached, this is after about 5 hours, it slows as it cools down.

I loose a quart after about 6 hours of driving.

I'm not really looking forward to pulling the tranny to get to the seal, and don't want to do it until after the season. I made a catch pan so it's not dripping on the exhaust anymore.

Thoughts, opinions. thanks.


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## kimber750 (Sep 19, 2011)

So you have a pan of oil sitting above the hot exhaust?


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## boutch (Aug 3, 2015)

Wow a quart in 6 hrs. i dont think it can get any worst then that.


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## areoseek (Mar 13, 2013)

kimber750 said:


> So you have a pan of oil sitting above the hot exhaust?


nope. it's under the bell housing.


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## dieselss (Jan 3, 2008)

Personally I'd fix it now. still warm and not under the gun to fix it just yet


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## Randall Ave (Oct 29, 2014)

Just do the repair and get it over with. Or, she's over 20 years old, maby time to update


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## Dogplow Dodge (Jan 23, 2012)

Tighten the pan gaskets first. If not drop it off at a local trans shop and have them spend a couple hours fixing it. Or as Randall said... Trade her in


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## Randall Ave (Oct 29, 2014)

He could just leave it, it's like automatic fluid film at one quart every 6 hrs


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## mpriester (Oct 2, 2011)

Change it. It can get a lot worse.


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## areoseek (Mar 13, 2013)

Going to pull the tranny today and change it out. thanks guys.


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## dieselss (Jan 3, 2008)

Sounds like the best idea good luck


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## FredG (Oct 15, 2012)

dieselss said:


> Sounds like the best idea good luck


X2 It will only get worse. I had a 351W performed a lot better than the 5.4 IMO.


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## areoseek (Mar 13, 2013)

dieselss said:


> Sounds like the best idea good luck


Got her all done this afternoon! Was able to do it w/o dropping the trans, just slid it back on the bolts and held it up with a ratchet strap! No more leaks!


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## Jeep_thing (Mar 3, 2014)

areoseek said:


> Got her all done this afternoon! Was able to do it w/o dropping the trans, just slid it back on the bolts and held it up with a ratchet strap! No more leaks!


Good job!


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## FredG (Oct 15, 2012)

areoseek said:


> Got her all done this afternoon! Was able to do it w/o dropping the trans, just slid it back on the bolts and held it up with a ratchet strap! No more leaks!


Your all set, Good for you. You would of worried yourself to death if you tried to get another season out of it. Besides you would of spend a fortune on oil. Good Luck. lowred:


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## FredG (Oct 15, 2012)

Jeep_thing said:


> Good job!


Jeep, Are you in Central or western part of upstate? Or down by Albany?


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## Jeep_thing (Mar 3, 2014)

Rochester. Yes they now call us 'Western NY' but growing up it was always Upstate lol.


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