main bearings
#1
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Year: 1989
Model: Cherokee
Engine: 4.0L Rebuilt Renix "Low Output" haha
main bearings
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
#2
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Year: 2000
Model: Cherokee
Engine: 4.0
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.
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.
Last edited by Jamie57; 10-26-2009 at 04:39 PM. Reason: additional info
#4
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Year: 1989
Model: Cherokee
Engine: 4.0L Rebuilt Renix "Low Output" haha
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?
#5
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Year: 1995
Model: Cherokee
Engine: 4.0
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
Rod bearings are cheap. Do it while your down there.
Good Luck
#7
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Year: 1989
Model: Cherokee
Engine: 4.0L Rebuilt Renix "Low Output" haha
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
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#10
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Year: 1989
Model: Cherokee
Engine: 4.0L Rebuilt Renix "Low Output" haha
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?
#12
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.
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.
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Model: Cherokee
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?
Besides low oil pressure, is oil consumption another symptom of any of the aforementioned failing parts? Or would oil consumption point direction at rings?
#14
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?
Besides low oil pressure, is oil consumption another symptom of any of the aforementioned failing parts? Or would oil consumption point direction at rings?
#15
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Year: 95
Model: Cherokee
Engine: 4.0
crank bearings
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.