78 F-100 engine problems
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Joined: Apr 2009
Posts: 14,333
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From: Stanley, VA
Man, this bites! Everything that I've read, also says to remove the "spike or pin" if converting to the rubber seal. So, the spike isn't there, but it doesn't look like anyone removed it. If I use the neoprene seal (even if installed correctly) it will always leak a little
if I go with the rope, it might not hold up without that spike
if I go with the rope, it might not hold up without that spikeOne thing to consider, make your own pin.
I would get a small diameter roll pin drill a hole through the cap (according to what I've read, from the factory it's not a blind hole, it's drilled through) and use the roll pin as the spike.
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Senior User
Joined: Sep 2013
Posts: 429
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From: New Hampshire
So, I've been talking to another gentleman over in the 335 forum. He has three M blocks. One is a 70's era 400, ones a 81 351M. Both of these blocks are on stands and he took a look at both rear main caps and neither has pins. Both of those cranks have the knurling and came factory with neoprene seals. The third engine is in a truck that's up and running, it is running a neoprene seal, but he's not sure if it came from the factory that way as the motor had been rebuilt before he got it.
I forgot to ask him if his running truck leaks oil, but I doubt it with how diligent he is about his vehicles.
So I'm going with the neoprene and see what happens.
I forgot to ask him if his running truck leaks oil, but I doubt it with how diligent he is about his vehicles.
So I'm going with the neoprene and see what happens.
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Senior User
Joined: Sep 2013
Posts: 429
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From: New Hampshire
Me too, I don't think the y make Depends that will fit a 351M!
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Senior User
Joined: Sep 2013
Posts: 429
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From: New Hampshire
The seal is changed and everything is buttoned up. I took it for about a 10 minute ride and no leaks. Took it for a 5 min ride and saw a little oil coming down the flywheel cover
not as bad as last time, but then again it's still too early to tell.
One thing I forgot to mention from before is that I noticed oil on the starter (where the black part mates with the part that is bolted to the bellhousing) and on the bottom starter bolt. I figured this would go away with the seal and pan gasket being changed. It did not
not as bad as last time, but then again it's still too early to tell. One thing I forgot to mention from before is that I noticed oil on the starter (where the black part mates with the part that is bolted to the bellhousing) and on the bottom starter bolt. I figured this would go away with the seal and pan gasket being changed. It did not
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FuelishPleasure
1973 - 1979 F-100 & Larger F-Series Trucks
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Nov 9, 2010 10:48 AM