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1G 1g tob noise & rpm drop - crankwalk

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AWD-Tony

Proven Member
6,801
3,735
Sep 11, 2017
Cincinnati, Ohio
My oe tob of 2 years started making noise and when I press the clutch, the noise goes away and rpm’s drop. In the video you can hear and see what’s going on. Engine has a hard time reving and rpm drops faster with clutch depressed. Don’t think it’s crank walk as I don’t see any movement on the balancer. You guys think it’s just a tob? I don’t see anything that stands out in my log.

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It goes just past this to 27 with a pry bar. Would this be .027? .0005 graduation. And is this crank walk? Also, what’s the limit for 6 bolt?

TOB seems fine btw so I’m thinking it’s cw

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It goes just past this to 27 with a pry bar. Would this be .027? .0005 graduation. And is this crank walk? Also, what’s the limit for 6 bolt?

TOB seems fine btw so I’m thinking it’s cw

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It's moving from 0 to 27?
That gauge is .0005. Three zeroes. Meaning the graduation is a single thousandth as it should be. Unfortunately this also meant you have .027 movement with is nesrly 4 times the allowable limit. You have crankwalk.

Just in case I'll clarify. If you zero that have and move it ba k and forth is shouldn't move more than 7 marks. .007.
Yes you are correct if it moves 27 that's. 027.
 
The main numbers are .001" (thousandths of inch). Each tick is .0005". Your picture is showing about .0245" (24-1/2 thousandths) if you started with it "zeroed" & needle is moving clockwise. Dail indicators can be read CW or CCW. If your measuring is accurate your endplay is 3x past the limit. Sorry but this would be crankwalk. Measured twice?
 
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The main numbers are .001" (thousandths of inch). Each tick is .0005". Your picture is showing about .0245" (24-1/2 thousandths) if you started with it "zeroed". If your measuring is accurate your endplay is 3x past the limit. Sorry but this would be crankwalk. Measured twice?
Whoops. Yes you're right each tick is .0005. But still it's way over service limit.
 
Yes. One full rotation is .050". You multiple .05" by the number of rotation count & then add the last remaining measurement before completing another full rotation. Gently push the plunger with your finger and watch how the 2 dials coincide.
 
Yes. I did zero it out with the crank pulled towards the front and needle is moving clockwise. So I do have cw.

What’s the next step after dropping pan?

The main numbers are .001" (thousandths of inch). Each tick is .0005". Your picture is showing about .0245" (24-1/2 thousandths) if you started with it "zeroed" & needle is moving clockwise. Dail indicators can be read CW or CCW. If your measuring is accurate your endplay is 3x past the limit. Sorry but this would be crankwalk. Measured twice?
Yup I measured 3 times. It clicks when I pull and push hard on the balancer.
 
You might as well just pull the motor. Motor's going to be coming out sooner or later to fix this. Schedule a motor rebuild for the future.
 
You might as well just pull the motor. Motor's going to be coming out sooner or later to fix this. Schedule a motor rebuild for the future.
I’ll probably slap it back together and sell it tbh

I appreciate everyone’s input
 
Sorry Tony.. It seems the CW has just begun. But probably the damage is still minimum.

BTW, the value of crank end play in the manuals above are not exactly the same as the original from Mitsubishi.
The standard value is 0.05mm~0.25mm (0.002"~0.010"). And the limit is 0.40mm (0.016").
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I’ll be dropping the pan to inspect further. Once the pan is off, I’ll inspect the play, thrust bearing & surfaces on crank and block. Since this just started, what’s the likelihood of getting away with just bearing replacement?

Crank is toast as the bearing wore into it. How can I tell if the block is any good?

I have the kiggly girdle but my machine shop couldn’t line bore it. Could this be a contributing factor?

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Crank is toast as the bearing wore into it. How can I tell if the block is any good?
Since crank walk means at least you have a metal to metal contact at crank journal #3, so you can't avoid the damage on crank #3 journal sidewall and #3 bearings once it occurs. And usually that's the minimum damage. The pic 2 and pic 3 are kind of typical wear at the beginning of crank walk.
If you don't see any contact mark or heat damage on #1/2/4/5 journal sidewall on the crank and the block/main caps, probably the block is still reusable by reconditioning.
I have the kiggly girdle but my machine shop couldn’t line bore it. Could this be a contributing factor?
I don't think that's the direct cause of the crank walk but it could have affected.
 
Since crank walk means at least you have a metal to metal contact at crank journal #3, so you can't avoid the damage on crank #3 journal sidewall and #3 bearings once it occurs. And usually that's the minimum damage. The pic 2 and pic 3 are kind of typical wear at the beginning of crank walk.
If you don't see any contact mark or heat damage on #1/2/4/5 journal sidewall on the crank and the block/main caps, probably the block is still reusable by reconditioning.

I don't think that's the direct cause of the crank walk but it could have affected.
I don’t see any contact marks on the cap side and it’s hard to tell on the crank. I’ll have to remove the crank to inspect it and the upper half of the block. Is this a procedure when assembling 4g blocks?

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That sucks Tony, do you know what caused it?
No clue tbh. Assembly error by me or not getting it align honed possibly. I'm going to have the machine shop assembly the rotating assembly this time.
 
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