351w rear main replacement

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Apr 3, 2013 | 07:26 PM

kenrussel85

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351w rear main replacement

I just bought a 1990 F250 4x4 with a 351 and an auto tranny, only to get home and find oil dumping out between the tranny and engine. I want to know if there is a way to swap the seal out without removing the engine, as I live in an apartment and they kinda frown on that. I figure the tranny and transfer case, driveshafts also, have to be removed, but how hard is it? Any advice would be helpful, my woman isn't too happy with me as is with the oil leak.

Apr 3, 2013 | 08:21 PM

DBGrif91

Cargo Master

Joined: Jul 2009

Posts: 2,541

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From: Des Moines

I can't point you to specific posts, but I can remember at least a couple of guys on this forum claiming to have replaced the rear main seal with the engine in. If I remember correctly, once the oil pan was removed, they LOOSENED but did not remove the main bearings on the crank and then got enough pull on the tail to be able to replace it.

But don't quote me on that. Do more research before attempting to replace the seal that way.

Apr 3, 2013 | 08:53 PM

dmanlyr

Fleet Mechanic

Joined: May 2005

Posts: 1,575

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From: Puyallup, WA

It should be a one piece rear main seal. That means you are going to have to split the engine and tranny.

As to the amount of work, it is a pain if you do not have the proper lift and jack for the transmission. wood cribbing cut to fit would work, but not as nice as the proper tools, and, of course, if you don't have the jack and supports, well anything is possible, just how much you want to beat up your body wrestling around with heavy mechanical components while laying on your back.

And you are sure it is engine oil and not transmission oil that is leaking?

David

Apr 4, 2013 | 07:14 AM

sticky58

Junior User

Joined: Mar 2012

Posts: 73

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From: Fort Erie Ontario

have a real close look above tranny to make sure it isn`t the intake seal,if the back seal that runs along the block from head to head,leaks, they will give the look that it coming from between the engine and tranny.You will not get drivability issues,just a good size leak. Just my 2 cents worth and worth checking before pulling tranny

Apr 4, 2013 | 08:17 AM

timbersteel

Logistics Pro

Joined: Mar 2005

Posts: 4,698

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From: Mexico, Missouri

There's a great Write-Up on FSB.com or Supermotors.com...i can't remember which..either way you can count on needing a tranny jack, a weekend, several cases of beer depending on the "5 Stages of working in a Project". DBgrif has this as his signature line...I'm veering off topic...anybody want to post that write-up for "Rear Main Seal repair/replacement".. I dont have the link, but you can "Bing.com or Google.com" that topic as I wrote it, it should bring it up in Seach results.

Apr 4, 2013 | 11:03 AM

Evan_P

Logistics Pro

Joined: Mar 2012

Posts: 3,507

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From: Oregon

Here you are. Have it bookmarked as I think I might be doing mine this summer.
Rear Main Seal Change Write-up, What and What Not to do (56K...I wouldn't) - FSB Forums

Apr 4, 2013 | 09:04 PM

kenrussel85

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Thanks guys for the replies. As for it being engine oil or tranny fluid dmanlyr, I wasn't able to tell. By the time I got to it today the storms had just passed through and cleaned away all fluids. I did try starting the truck again though, and got under to see if I could find it. I can see oil from the valve cover gaskets, but not with the flow rate as yesterday. Right before I shut it off though, I heard a horrible noise that sounded like something was being thrown around either in the oil pan or the tranny bell housing.

It has the e40d if that helps at all. Stickey58, I'll check that rear intake seal tomorrow, that would be great if taking the top end apart fixes my problems