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Crankshaft Catastrophe

Veg_Out said:
The sound was like gravel and concrete with a few big rocks inside a cement truck, like you had a microphone right inside.

I heard the knock, and had been hearing in for a couple weeks. Figured it was time to test injectors, replace the crankshaft pulley etc. Was talking with Slim Shady on the tele and he suggested tightening the torque converter bolts. I agreed and headed home for the day. I wanted to hear if the knock went away at higher rpm, so while I was doing about 30, near my house, I slipped it into Neutral and revved, not very high, maybe 1800 rpm, and all of a sudden, the worst possible gravel in your motor/tranny noise you've ever heard.

I have located a 6.2. I have made a deal for it, I think. I have never pulled a motor before, and I'm a little nervous about it, but do have access to an "ok" shop.

Then today, I popped by the mechanics shop and he asked me, "has it always rolled while in park," right after he'd suggested that he was 90% sure the crankshaft had broken. I answered "no". He did start it and it died/he thinks it locked up. Ran and sounded like scary hell for 10 seconds, and now won't turn over.
If I need a tranny, I've found a couple of 6.5 trucks around Boise with blown motors, and I can buy the whole heap for less than a tranny.
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i would unbolt he TC,push it back out of the pilot and fire it up.i bet the mill runs just fine.
 
bison said:
i would unbolt he TC,push it back out of the pilot and fire it up.i bet the mill runs just fine.
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X2. Just pull the TC bolts and see what turns. TC or engine. The trans pump can lockup the engine.

Trans in and out rebuild can be done for $895 plus hard parts on a 4x4. Hard parts are like OD gears etc.

My transmission blew a bearing and sprag in the OD unit. The parts went through the OD planet and ruined the gears. $250 for those hard parts.

Sounded like I was dragging the exhaust on the pavement when it went into OD. Trans temp then went over 250...

3 weeks to get an engine in and out... Yes it is a big job, but, a cake walk over a Duramax. You can get to everything fairly easy to get it out.
 
I had a similar thing happen to me a few years back in my '84 Monte Carlo SS. Driving along not really going fast maybe 40mph, and BANG then sounded like rocks in a can and it quit. Thing made a god-awfull racket and wouldn't run more than a few seconds, so i figured the engine had grenaded - it had lots of miles on it. I built a new engine, took the old one out & started looking at it - nothing looked wrong. I turned the torque converter over a few times, there was the noise!! Evidently the lockup portion of the converter had grenaded internally and spewed crap throughout the tranny that locked up the engine & destroyed the trans internals. Replaced the tranny/converter & all was good, i never cease to be amazed at failures anymore!!!
Don
 
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Veg_Out said:
Yes, this was my exact next question/point.
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Yes it might be a bitch.most bolts can be reached from below,might have to modefy a ratchet wrench to get the highest one's. If that fails,you can unbolt the tranny and push it back a bit and work from the top.You might get lucky and be able to turn the engine backwards.
Dont be surprized if you invent new cuss words:smile5:
 
bison said:
Yes it might be a bitch.most bolts can be reached from below,might have to modefy a ratchet wrench to get the highest one's. If that fails,you can unbolt the tranny and push it back a bit and work from the top.You might get lucky and be able to turn the engine backwards.
Dont be surprized if you invent new cuss words:smile5:
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Perhaps I can sell some new cuss words at walkingjdesigns.com? Looks like I'll be needing the cake!
 
Worst case you could pull the engine with the torque converter still attached, leave the tranny in the truck, and pop off the oil pan & main caps and pull it with what's left of the crank if it's seized. A little more headache but i'd lot rather do that than fight with the upper converter bolts in the truck. :nonod:
Don
 
The picture says it all.
 

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Lots of great discussion here guys.

Has anyone looked at the oil pan to see if there are any big dents in it? I've seen diesels grenade and the common denominate is holes in the pan/block with parts sticking out! Oh yeah, alot of oil on the undercarriage also.

Good luck Veg!
 
daustin said:
Worst case you could pull the engine with the torque converter still attached, leave the tranny in the truck, and pop off the oil pan & main caps and pull it with what's left of the crank if it's seized. A little more headache but i'd lot rather do that than fight with the upper converter bolts in the truck. :nonod:
Don
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I hope you would;nt do that with a good engine would ye, if its the tranny you want out):h
 
We've got metal flakes on the dipstick. Current guess is thrown rod. Draining oil this afternoon to verify.

The suggestion of removing the engine with the converter attached is what we will likely do.
 
You are right Dan. But, I was really hoping for one of those "made it 400k" stories. It was running so good. I guess the bulb burns brightest before burnout.
 
Veg_Out said:
You are right Dan. But, I was really hoping for one of those "made it 400k" stories. It was running so good. I guess the bulb burns brightest before burnout.
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Yes, it's usually a flash, or in this case a bang:smile5:
 
Easiest way I found my broken crank was to remove the flex plate cover, put a socket on the balancer bolt with a breaker bar and rock it back and forth.

My balancer moved about an eighth of a turn while the flex plate stayed still.

I think there is supposed to be a solid piece of seel connecting the two:smile5:
 
I wonder what the percentage of us on this site running 6.5's are actually running on their 2nd or more motor?
 
The 95HD and the 97 3500 in my sig both blew the engines before 100,000 miles. The 92 and 95LD both have over 250,000 miles on original engines. I think alot has to do with luck.There has to be many fleet engines that made it to 400,000 miles. Where I used to work, the gasser engines were making it to 300,000 miles.
I'm trying to figure out why the 94 that I'm working on busted the crank. The balancer checked out good.
 
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