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What would cause this and how to fix?

What would cause this and how to fix?

Vikingone

Senior Jeeper
Posts
594
Thanks
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Location
Lake Worth FL
Vehicle(s)
85' CJ7, 4.2 Liter, swapped in T18
Bearings aren’t looking so hot. 5da91ab5fb901a935ace4e42d4af78d2.webp ea2c795433f306af428f5f5f0130f57d.webp


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Engine wasn't 'pre-oiled'(oil pump not spun up to psi)before first start after rebuild.
Engine was not prelubed during assembly.
Crappy bearing set...
OLG
 
Remember when I said to go hard or go home???

Hahahahaaha.

Those aren't the best looking, but they're not the worst. Any little bit of foreign material in there will cause scoring on a bearing. From the pictures, I can't tell if one side is worse than the other.

What does the crank look like?

I recommend taking a good look at the crank. If it's scored up pretty bad, you can have them hone it for you and get the correct size bearings. Either way, I'd take it to a machine shop to at least get it measured to make sure you get the right size bearings, because it could have been honed once already...especially if a PO rebuilt it.

When you put it all back together, do everything you can to keep foreign material off your parts and out of your block. Cover with a heavy garbage bag when you're not working on it.

And use assembly grease when you put everything together. That first start will be hell on every moving part, so protect it as much as you can.

Torque everything to spec...especially if you have to do it in steps. That's where the service manual comes in handy.

And remember, there's more to rebuilding an engine that just taking it apart and putting it all back together with new bits. You need to make sure gaps between the crank and bearings are within tolerance, crank end play, etc. I mean, I guess you could just put everything back together and hope it all works out, but I highly recommend checking all of your work against procedures in the service manual.

I think it's time to start a build thread! Keep it all in one spot.
 
:agree:

LG
 
Remember when I said to go hard or go home???



Hahahahaaha.



Those aren't the best looking, but they're not the worst. Any little bit of foreign material in there will cause scoring on a bearing. From the pictures, I can't tell if one side is worse than the other.



What does the crank look like?



I recommend taking a good look at the crank. If it's scored up pretty bad, you can have them hone it for you and get the correct size bearings. Either way, I'd take it to a machine shop to at least get it measured to make sure you get the right size bearings, because it could have been honed once already...especially if a PO rebuilt it.



When you put it all back together, do everything you can to keep foreign material off your parts and out of your block. Cover with a heavy garbage bag when you're not working on it.



And use assembly grease when you put everything together. That first start will be hell on every moving part, so protect it as much as you can.



Torque everything to spec...especially if you have to do it in steps. That's where the service manual comes in handy.



And remember, there's more to rebuilding an engine that just taking it apart and putting it all back together with new bits. You need to make sure gaps between the crank and bearings are within tolerance, crank end play, etc. I mean, I guess you could just put everything back together and hope it all works out, but I highly recommend checking all of your work against procedures in the service manual.



I think it's time to start a build thread! Keep it all in one spot.



Yeah I figure I’m this far in. A machine shop is a good idea. And I’ve already started a build thread. Check it out.


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Yeah, just saw it. Before you do anything else, get the service manual. Can't go wrong if you follow procedures in there. You'll definitely learn a lot.

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Yeah, just saw it. Before you do anything else, get the service manual. Can't go wrong if you follow procedures in there. You'll definitely learn a lot.

Sent via Google translate using braille through Tapatalk



I have a Haynes manual. Also have a chiltons manual from back in the day. Are they good enough?


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I have a Haynes manual. Also have a chiltons manual from back in the day. Are they good enough?


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No.....
You want a real FSM.
LG
 
Birthday is coming up. Maybe I can get the wife to buy it:)


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You're going to need it before then !
 
I would NOT touch another part of that jeep until you have the FSM in hand.
LG
 
Bearings aren’t looking so hot. 5da91ab5fb901a935ace4e42d4af78d2.webp ea2c795433f306af428f5f5f0130f57d.webp


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The first pic is your thrust bearing, usually it will look like that on motor with lots of miles or could have been started with someone pushing in the clutch on inital start (a no no), also as said before no prelube. The second pic looks like a high mileage bearing (normal), poor maintence or poor cleanliness on assembly on a low mileage motor.
As said before lube everything on assembly, also Lucas makes a good engine breakin lube for flat tappet cams.
 
Last edited:

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