Common oil leak??
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Common oil leak??
I have recently acquired an '86 F250 302EFI 4-speed truck in great shape. The only problem is that it seems to have a serious oil leak that drenches the gearbox. I'm wondering if it is the rear intake manifold seal leaking oil down the top of the bell housing and onto the tranny. It is difficult to see back there, is this a common leak point or should I be looking elsewhere? Thanks in advance for any help 
(Note: It does not appear to be gear oil, so I'm focusing on the engine.)
(Note: It does not appear to be gear oil, so I'm focusing on the engine.)
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Joined: Jun 2004
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check to see if the shifter plate(the suare part of the shifter assembly that bolts to the top of the trans) is leaking, sometimes it comes loose and gear oil will leak out of it but only when it is running with the clutch out. gear oil will sling off the gears inside and find its way out if the seal is bad or if the bolts are loose.
Elder User
Joined: May 2004
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From: Edwards Air Force Base
On 302 engines, the oil leaks are usually on the valve covers as another poster said or the rear main seal.
I have owned many 302 ci in everything from Grand Marquis to Pickup trucks and they all seem to have a hard time keeping the valve covers tight and dry and after 100k miles, start dripping from the rear main seal. They will keep going though so just think of it as an "anti-rust" system.
I have owned many 302 ci in everything from Grand Marquis to Pickup trucks and they all seem to have a hard time keeping the valve covers tight and dry and after 100k miles, start dripping from the rear main seal. They will keep going though so just think of it as an "anti-rust" system.
Senior User
Joined: Jun 1999
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From: Nova Scotia
My 302 leaks from the valve covers and maybe the rear main seal... looks worse than it is as I only have a cople small spots in the driveway. I add a quart every 1000-1200kms so that isn't bad. It is cheap undercoating.
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Senior User
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From: RI
Sometimes too, those valve cover bolts just loosen up. Maybe they just need to be tightened....could stop the oil leak if you're lucky.
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It appears to be the rear main seal. The flywheel must be flinging oil all around and it's finding its way around the outside of the bellhousing and down onto the tranny. Fortunately the clutch seems to be staying dry. Is it a two piece seal on these motors?
Hotshot
Joined: Feb 2004
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From: Marengo, Iowa
about the bolts, I'm sure there's a proper spec, I just snug them down, but not super tight. My habit is to grab the ratchet (3/8) by the head, so as not to get much torque, and tighten that way.
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From: Southern Arizona
Your rig has a one piece rear main seal. To replace, the flywheel/flexplate has to come off. I would also check to see whether you might be leaking from the rear of the intake manifold. I have seen a lot of leaks from there on 289's, 302's and 351's. As mentioned earlier, not a critical leak but worth keeping your eye on.
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