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Replacing Rod Bearings. Easy?

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Old Mar 2, 2009 | 09:31 AM
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Replacing Rod Bearings. Easy?

well, i guess the stock motor didnt like the 7.5k redline with the conventional oil(oops) and now im getting a knock from one of my rear bank cylinders.

So now im debating on doing another 3.5 swap or changing out the rod bearings.

My question is, could i just drop the oil pan, crankcase/upper oil pan and that cradle thing thats hold the crankshaft then just unbolt the connecting rods, push them up and remove/change the bearings?

OR

do i HAVE to drop the crankshaft out via removing all the timing assembly, tranny and flywheel?

I pretty much just wanna reach up in there and swap them out if possible.

Im also questioning this method because this is how my friend did it on his Taurus SHO
Old Mar 2, 2009 | 09:48 AM
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Believe it or not, you could set the cylinder you're working on at BDC and probably be able to push the connecting rod/piston up, but I dont know how much room you'll have with the crankshaft and counterweights in the way. If you take the caps off, you could actually shift the big end of the rod over and rotate the crank a little so the journal is over to one side, and the rod is on the next, put the bearing in, and rotate the crank, making sure the rod is out the way, seat the rod with bearing on the journal and repeat. On my next disassembly, maybe ill simulate the motor being in the car on the engine stand just to see how much clearance we'd have. In theory, I think if you're careful, it could be done and would save lots of time.



Thats the best pic I have at the moment.

Last edited by TJ_Max; Mar 2, 2009 at 09:53 AM.
Old Mar 2, 2009 | 10:31 AM
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Mmmmmmmm
Old Mar 2, 2009 | 10:39 AM
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tat pic helps out ALOT!! i was looking for a picture just like that. the FSM has the etch-a-sketch drawing of one and doesnt help too much and i tossed my old 3.0's so i had nothing to look at for reference. Think ill try this tomorrow
Old Mar 2, 2009 | 08:50 PM
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If the bearing is bad, odds are the crank pin needs to be machined. A complete teardown is necessary.
Old Mar 2, 2009 | 08:59 PM
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Originally Posted by nismology
If the bearing is bad, odds are the crank pin needs to be machined. A complete teardown is necessary.
geesh, there went my day well guess ill just go buy another 3.5 and put some cosworth heads on it


FYI, it only knocks at around 3k in up.. not bad at all yet but i dont drive it anymore.. 2.5k and below, dont hear a thing. Could this mean i just have to change the bearings and the crank pin might still be good?
Old Mar 2, 2009 | 10:44 PM
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Whats crazy about it all is you can drop the crank with the engine in the car, lol. More tricks to keep the pistons up, but woulda been a pretty cool experience if you ask me. I do agree with nismology in that, you cant just change a rod bearing, you have to correct what caused it to go bad in the first place,and then fix any damage that could be associated with the bearing issue. Doing things right is a **********.
Old Mar 2, 2009 | 10:48 PM
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Originally Posted by TJ_Max
Whats crazy about it all is you can drop the crank with the engine in the car, lol. More tricks to keep the pistons up, but woulda been a pretty cool experience if you ask me. I do agree with nismology in that, you cant just change a rod bearing, you have to correct what caused it to go bad in the first place,and then fix any damage that could be associated with the bearing issue. Doing things right is a **********.
yea i agree and sadly to say, imma 1/2 a**ed kinda guy sometimes when it comes to things like that.. I honestly think the bearing might have just warped but owell... Ill set it aside and rebuild it later or something ..

I still might drop the crankcase tomorrow and try it. Ill keep everyone updated to let them know the process
Old Mar 3, 2009 | 07:10 AM
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Originally Posted by ghostmax301
yea i agree and sadly to say, imma 1/2 a**ed kinda guy sometimes when it comes to things like that.. I honestly think the bearing might have just warped but owell... Ill set it aside and rebuild it later or something ..

I still might drop the crankcase tomorrow and try it. Ill keep everyone updated to let them know the process
At the least, you'll learn something new - and what else can you hurt if you do change a bad rod bearing ?? It might work for a while if the journal isn't chewed up.
Old Mar 3, 2009 | 09:06 AM
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Nitrous FTL.
Old Mar 3, 2009 | 10:38 AM
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Originally Posted by ajcool2
Nitrous FTL.
honestly dont think it was the nitrous, that could possibly mess up the valves but i think it was just engine heat too hot and conventional oil. had 150miles on a new oil change, drained it out and it had broken down into almost water like and was BURNT!.

I think i need a new radiator or something too because my idle temp is around 186-195*
Old Mar 3, 2009 | 03:14 PM
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ok, going to attack it tomorrow!!

Quick question though, if the journals are SLIGHTLY scratched, can i lightly sand with 1000-3000 grit sand paper?
Old Mar 3, 2009 | 06:04 PM
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Originally Posted by ajcool2
Nitrous FTL.
I was thinking more like nitrous+7500rpms+stock rod bolts= knock knock

btw do not sand it, it'll mess it up and that rod will have very low oil psi and wipe out the bearing/crank journal to the point were the crank it too far out of wack and can be re-machined for over sized bearings

just replace the bearing baby the motor till you get a chance to rebuild or replace
Old Mar 3, 2009 | 06:07 PM
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Originally Posted by ghostmax301
i think it was just engine heat too hot and conventional oil. had 150miles on a new oil change, drained it out and it had broken down into almost water like and was BURNT!.
hey are you using the 3.5 oil pan and cooler
Old Mar 3, 2009 | 06:18 PM
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motor swap should be cake walk for you..just use synthetic since you rev so high
Old Mar 3, 2009 | 09:50 PM
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I was thinking more like nitrous+7500rpms+stock rod bolts= knock knock

btw do not sand it, it'll mess it up and that rod will have very low oil psi and wipe out the bearing/crank journal to the point were the crank it too far out of wack and can be re-machined for over sized bearings

just replace the bearing baby the motor till you get a chance to rebuild or replace
yes, im using 3.5 oil pan and cooler and when i spray, i would let off the button at about 6.3k then N/A to about 7.2k. Only reved to 7.5 if it was a close race or at the top of 4th

and now that you & my father say that about the journals, im just gonna grab this other motor. cause it hard for me to baby a motor lol
Originally Posted by JAMAICANLOVRBOY
motor swap should be cake walk for you..just use synthetic since you rev so high
it really is.lol just took me 2 1/2 days to do one from driving in to backing out with a 3.5 with a floorjack and hand tools.lol

and full synthetic all the way now from now on
Old Nov 14, 2011 | 08:38 PM
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Sorry to bring up an old post, but has anyone confirmed that you can in fact change the bearings with the engine still in the car?
Old Nov 15, 2011 | 12:34 PM
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My brother did it.
Old Nov 15, 2011 | 12:34 PM
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LOL@ my comments in this thread
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