Crank walking
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Crank walking
Well I took my new motor back to my engine builder to see whats been going on because the car was throwing a P0336 crank sensor performance code. The builder pull the oil pan and seen the thrust bearing was chewed up on the back side and the crank to. The engine builder said something was pushing on the crank, but what? When I put the motor and trans together I did it while they where out of the car and it bolted up great nice and smooth. The trans is a th400 with a TCI ultimate street fighter stall and TCI flexplate. What do you guys think? Now I'm spending more money rebuilding the motor again and I don't want to put it all back together to do it again.
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Somebody said the rear main bearing could have been installed wrong causing the crank walk? I also talked to some tranny guys and they said that if there was a problem with the stall bring installed wrong it would of chewed up the splines on the trans and they look good and the trans felt good.
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Originally Posted by Z28FirefighterI1
Well I took my new motor back to my engine builder to see whats been going on because the car was throwing a P0336 crank sensor performance code. The builder pull the oil pan and seen the thrust bearing was chewed up on the back side and the crank to. The engine builder said something was pushing on the crank, but what? When I put the motor and trans together I did it while they where out of the car and it bolted up great nice and smooth. The trans is a th400 with a TCI ultimate street fighter stall and TCI flexplate. What do you guys think? Now I'm spending more money rebuilding the motor again and I don't want to put it all back together to do it again.
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I know when I put it together I had clearance I could still spin my convertor. I don't know what to do? I can't tell the engine build that he's wrong and he screwed up thats just not going to work. What ever happened to the motor I need to know so it doesn't happen again.
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Originally Posted by Z28FirefighterI1
I know when I put it together I had clearance I could still spin my convertor. I don't know what to do? I can't tell the engine build that he's wrong and he screwed up thats just not going to work. What ever happened to the motor I need to know so it doesn't happen again.
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Like Collins mentioned, if someone hammered the crank pulley on, that could have messed the bearing up in the first place and then it got progressively worst. The only other option is that the bottom end wasn't put together right, 'cos a convertor shouldn't do that without causing other catastrophig failiure of some other system.
Not trying to say anything about your engine builder either but we had a customer who's engine (that was built by someone else) started making a real bad knocking sound after a few track passes and the engine builder told him it's probably because he pulled the wheels on the final launch before the bottom end acted up ... he's fixing it for free though but that's a bunch of BS, all our cars should have bottom end problems if that's true! Not everybody would admit an honest mistake.
Not trying to say anything about your engine builder either but we had a customer who's engine (that was built by someone else) started making a real bad knocking sound after a few track passes and the engine builder told him it's probably because he pulled the wheels on the final launch before the bottom end acted up ... he's fixing it for free though but that's a bunch of BS, all our cars should have bottom end problems if that's true! Not everybody would admit an honest mistake.
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dude, for the life of me i can't remember what other small issues can cause this from the tranny side of things. probably too drunk tonight. i would give TCI a call. they are an easy bunch to talk to. that, or the thrust clearance just wasn't right when the eninge was built.
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If you know how the main bearings are crank go together, you'd see that a walking crank is pretty much impossible. For the crank to walk, the thrust bearing must be SERIOUSLY fugged up, or non-existant. With proper bearings and clearances, the crank thrust should be between .003" and .004". Mine came out to be .0035".
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Did you buy a flex plate that was made for a TH400 on an LS1 therefore it didn't require the spacer? Also, if you did use a spacer is is possible you had one of the truck cranks that doesn't need the spacer and you used one anyways? Just brainstorming here man I hope you get it figured out.
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The spec sheet on the motor said the crank end play was set to .005 and now its like .050. The flex plate was the one for the ls1 it came with a crank spacer and the motor did need it the crank was stock.
#18
You guys are not alone with this crank walking thing:
http://www.performancetrucks.net/for...hlight=bearing
It would be extremly valuble if the root cause for theese failures could be found.
Are there any common factors in the thre trust bearing faliures?
It is a bit scary......
Br//
http://www.performancetrucks.net/for...hlight=bearing
It would be extremly valuble if the root cause for theese failures could be found.
Are there any common factors in the thre trust bearing faliures?
It is a bit scary......
Br//
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Thanks for the link but I still don't know what caused it, they didn't know in the link but thats weird that theres that many that have this problem but knowbody knows how it happens.