less than 10,000mls one new longblock

Holy Crap!!! What kind of noises did that sucker make when that happened!?!

I don't understand how and why that would break on the front of the shaft.. not like it was on the back end from abuse or overload??? Must have been a stress point or defect?

i was about 100mls into my trip when i heard a faint knocking sound
followed by a what i thought was a loud back fire or a loud snap then motor died and that was it
doesnt look like anything else is damaged

it was prolly just a bad crank
lucky me i won

Was this a new shortblock or a reman engine?
If the crank was turned undersize with the wrong radius it can cause a weak spot.

I have never even heard of a 3.0 crank ever breaking like that, something was wrong with the rebuild i'm guessing.

i had bought a 2 door gen 1 for 100.00 for parts
and it had a remaned longblock in it that had never been started so i took off all of the parts down to the longblock and put all off my parts on it and put in my 4dr
ran great up until the crank snapped
so i guess ill put a new crank in it and see what happens
i have had nothin but bad luck with these 3.0s
my original 3.0s crank pulley had came off twice

That would be my take. Curious to see what undersize the rod bearings are stamped with. Mitsubishi had a TSB about not cutting the cast crank undersized. Pretty sure they use a rolled fillet on the crank that cant be duplicated on a rebuild.

Can you get a close up of the fracture?


Kevin

I also would like to see a good pic of the fractured area. I can also get the crank examined at a testing lab but I expect even at the photo level it will be clear where the failure propagated from.

To me this is another mark against remanufactured engines. Mass rebuilding of most foreign engines makes for some very unreliable crap.

I'd like to see a close-up picture of the main and rod journals.

In that last picture, the main journals appear to be uncut. The rod journals are harder to see, but also appear uncut, except for #2 which is right next to the break. That journal looks like it seized and shows no undercut fillet radius - perhaps the fillet is full of bearing material. Can you get a picture of the #2 rod? I'd want to remove it and check the color for heat damage and see if the wrist pin is ok.

It's hard to tell without better pictures, but try to take some and let's see if there's further damage that would suggest whether rebuilding that block is wise.

Frank

All the bearings look good except for the number
# 1
the short side of the broken crank moved front to back
and whore on the sides of the bearings
the bearings have a 25mm printed on them