Main bearings

[MouTine]

Can main bearings been changed underneath while engine is in car? I mean same way like rod bearings. If crankshaft is hanging by front and rear seals and tranny is supported, is there room enought to slide top bearing halfs away and install new ones?

Or did I just got major brain fart?

 

[96mystic_915]

drop the k member and have good luck

 

[ksigatmsu7f02]

I can honestly say I have never tried it nor heard of it being done but I would take the guess that you either wouldn't be able to get the old bearings out or get the new bearings in safely without scarring. Not to mention the wear on the crank that could potentially quickly ruin a new set of bearings....that guess is based on pulling one cap at a time....as for pulling all caps and letting the crank fall slightly....iunno....I wouldn't try it....

 

[96mystic_915]

you may be able to loosen both end caps and hang the crank then be able to do it but im not sure at all

 

[96mystic_915]

after looking at all the stuff involved you would have to drop the trans and pull the front and rear cover and pull the k member its easier to just pull the motor and do it there is no easy way to do it in the car its not like a pushrod motor so just pull the motor and make your life easy

 

[CJK440]

You can leave the crank in place. Keep in mind, there is some oil clearance already and the crank is sitting on the lower caps so all your clearance is up top too.

Since the bearings have a tang on one side you have to rotate that side out first. A trick is to remove the cap and lower bearing shell then rotate the crank until the oil hole in the crank is visable. Then insert something such as a short nail with a head larger than the oil hole (so you don't lose it) making sure the head of the nail sticks up off of the main journal no more than the thickness of the bearing (otherwise you will damage the block). Then manually rotate the crank in the proper direction until the head is touching the non-tanged edge of the bearing and make sure it sits against the edge of only the bearing and doesn't hit the block web.

Keep rotating and the shell will simply spin out.

I am not sure if/how you can R&R the C shaped thrust bearing in these motors though. And remove and torquing the side & Jack bolts will be fun too.



The bigger question is why are you R&Ring the mains?? I'm guessing if the bearings are worn/damaged there will be crank issues as pointed out above.

 

[96mystic_915]

pull the motor turn the crank and get new bearings

 

[MouTine]

The bigger question is why are you R&Ring the mains?? I'm guessing if the bearings are worn/damaged there will be crank issues as pointed out above.

Well... I have just a light litle knocking sound coming when flooring the gas pedal with low rpms and engine is hot. When driveing normal, cold engine or without load, there's no any abnormal sound. Im guessing its rod bearing and this main bearing s*hit just came up in my head, but maybe I pass it and stick with rod bearings. Thanks guys.

 

[96mystic_915]

if it was a consistant know it would be a rod but if it does not do it all the time i would try the rod bearings