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torque converter banging??? Flywheel or tranny??

3K views 5 replies 4 participants last post by  boneyard Buick 
#1 · (Edited)
hey guys
i got a 1989 blazer s10 with a 4.3L v6 and an older th350 transmission. The stock 700R4 blew up before i got the truck and it was replaced with a turbo 350 and a new torque converter. Lately when i've been starting the truck, theres a banging either in the starter or in the torque converter area. I put a 9/16 wrench on the bolt of the torque converter and moved it both ways, it will move about an inch and then stop and when you push the other way it goes about an inch then stops, im not sure if thats what th350's are supposed to do or if thats normal. Also i think it might be the starter because i was starting the truck the other day and something got in the way of the teeth for the flywheel and the teeth on the starter and made a *ping* noise and fell to the ground. The piece that came out is about 3/4" long and its a hollow pice of steel with a slit running down the side of it. Im not exactly sure if that would cause this problem and that piece that came out was something to do with the inside of the starter that allows the gear to come down and bang the flywheel or a clip to hold something in the starter, but i dont know where else this piece would come from, but im just posting it on the board to see if anybody had a clue. Also when i start the truck it has a rough "sounding" start and when its running its fine, but when i turn the truck off, the noise comes back until the crank stops moving and thats it. One of my buddies said it was the starter for sure, until i showed him that the torque converter moved about an inch either way then stopped, but im not certain if thats normal or not.. ANy help???? i have no idea and i just dont want to buying parts without fixing the problem. Thanks :thumbup:
 
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#2 ·
if the converter bolts r tight, then i would look at the flexplate, could be cracked. since the 4.3 is basically a 5.7 with 2 cyls. cut off, theres no difference in the back of the blocks.and the 350 shouldnt have any real issues, so thats where id start looking 1st.. gl
 
#3 ·
torque converter banging???

I had a chevelle that sounded like that and finally the flex plate gave out completely. it was cracked around the six bolts in the crank. if you unhook the coil an have someone crank the motor over watch the flex plate turn,it should not wobble or it is cracked.good luck
 
#5 ·
T C banging

It sounds like the flywheel broke at the flange of the crank, I have seen this happen a few times. And as far as the metal piece that you found, check the starter, there is a piece there that limits the travel of the bendix and it is probaly what that piece of metal was or part of it. Hope this helps, good luck, Happy wrenching!!!, :) , Perry.
 
#6 ·
hey guys
thanks for the help
but no one was right. LoL
It turns out that the flywheel bolts didnt have the washers on them, so the fywheel bolts backed out about an 1/8th each and the flywheel was really sloppy, but some of them were still tight so when i moved the flywheel by hand you couldnt notice it.

But when i found this out i just looked underneath to make sure once more and i seen the back of the crank imbetween the flywheel and i noticed the flywheel moved before the crank so thats when i started the tear down of the truck. But its fixed now, proper bolts and washers, starts and kills like a dream and the flywheel was not cracked at all. before i bought the truck the converter and flywheel were brand new.

Thanks for the help! :thumbup:
 
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