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Looking for Torque Specs

jweston71

New member
My husband and I are replacing

My husband and I are replacing rear main seal on a 1984 3.0L 140HP 4 Cyl. Mercruiser Motor. Can't seem to find the Torque specs for the Main bearing bolts. Can anyone help?
 
"Jenn:

You need to buy a ma


"Jenn:

You need to buy a manual (from this site, hopefully). It has all kinds of good advise in there--including torque specs.

Jeff"
 
"Jenn,

I have the detailed


"Jenn,

I have the detailed engine service manuals at my fathers house, I'll look it up and see what I can find for you. It covers every engine Mercruiser used, and should be in there. Give me a day or so."
 
"Main bearing cap bolts: 65 ft

"Main bearing cap bolts: 65 ft-lbs.
Rear main seal retainer nuts: 135 in-lbs.
New Seloc service maunal: Priceless.

BTW, are you sure the rear main seal is bad?
Some of Mercruiser's crankcase ventilation systems are woefully inadequate, causing oil leakage at the front and rear main seals."
 
"Thanks to all of you who resp

"Thanks to all of you who responded. I appreciate the help. There is a fishing tournament In a few weeks, and we are trying to get it back in the water by then. We have decided to get the manual, too. This boat went down on a nearby lake a few years ago, and I think they only did half of the repair job on it after they pulled it up.
So it will be an ongoing process for a while I think. But we get to enjoy it in between, without breaking the budget.

Thanks again to all."
 
"Troy,

Can you give me an


"Troy,

Can you give me an idea on how to know the difference? We took the seal out, and they looked pretty bad. When my husband tipped the motor up after we took it out, the oil ran out around the seal, but is there something else we should look for? And do we have to run it to tell? Because right now, we have it out of the boat.

Thanks again,
Jenn"
 
"Sounds like the seals need to

"Sounds like the seals need to be replaced anyway.
Now that the engine is out, I'd repalce them both anyway, just because... and look at everything else you can't see when the engine is in the boat.

Regarding the crankcase ventilation, my 5.7L had two small diameter corrugated plastic tubes running from the valve covers and just kind of pointed toward the air cleaner/flame arrestor. I had significant leakage from the front main seal. It wasn't continuous, but if I'd run the engine at about 3000 rpm for about 30 minutes, I'd loose a quart of oil. There was some misalignment of the timing cover gasket, but even after I fixed that, I was still seeing a lot of leakage. The engine, at the time, was a brand new factory short block so I really wasn't ready to go after the front main seal. After realizing the crankcase wasn't being ventialted properly, I replaced the corrugated tubing with regular 1/2" hoses. I drilled a hole in the top of the air cleaner and glued a plastic 'T' in there and connected the hoses to that. I also put a PCV valve in each hose to prevent a backfire from causing a crankcase explosion. That was three years ago and I haven't leaked a drop of oil since."
 
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