I am needing to replace my main bearings, and i was wondering what way i should do it. Do i need to pull the motor, or do i have to actually pull the crank out, or what do i have to do to replace those suckers. Thanks

 

Are you sure it's the main bearing and not the rod bearings?. They usually go first, unless you ran it out of oil.
Both can be done with the engine in the car. Much easier if you have a hoist. Cleanliness is the key.
Either way it's not a job for a rookie.

 

Drop the pan, and replace them. I would do your oil pump and rod bearings while your down there.

 

i just replaced the oil pump, and i still have low oil pressure so i was told to replace the main bearings. I know engines inside and out, and i have acess to a hoist, so does the crank have to be removed in order to get the top bearing out, or can it just be tapped out?

 

They make a tool or you can carefully use the old bottom bearing to slide it enough to grab it. Careful, dont hit the crank!

Rod bearings are cheap. Do it while your down there.

Good Luck

 

Oh and Jamie57 is right for sure, It takes a lot to wipe out a Main. It probably is your rod bearings.

 

i think what happened is the guy that had it before me didn't change the oil as much as he should.... so do i just need to replace the rod bearings, or the main, or both? oh and thanks for all your help

 

Personally I would do both. But good luck with whatever you do and let us know if it works!

 

Same here. do both. better than getting it all buttoned up and then finding you need to do it. What's 6 rod bearings go for $40?

 

ok thanks! so if i do both would it just be easyier to pull the motor out and do it all, or should i still just be able to do it all with a hoist, and dropping the oil pan?

 

You can do both on the hoist. Just take your time. don't rush it and do all the steps, including the plastigage!

 

The FSM describes how to replace the main bearings without pulling the motor. Drop the pan and let it sit overnight so the oil can drip off.

FWIW,
Low oil pressure is generally a cam bearing issue so don't be too shocked if the new main barings don't solve your problem. The cam is the first component to get oil from the pump, so once those bearings are worn the pressure drops off.

 

With low oil pressure as a symptom, how do you diagnose whether the cause is main bearings, rod bearings, cam bearings, a weak pump, or a failing OPSU?

Besides low oil pressure, is oil consumption another symptom of any of the aforementioned failing parts? Or would oil consumption point direction at rings?

 

Oil consumption would be the rings. Low pressure is as Frankz mentioned. The main and rod bearings would cause a knocking sound due to being worn.

 

Ive been told to do both while you have it pulled. I don't have the skill or hoist so Im having it done at shop. My oil pressure is still good.