1995 GMC Sierra noise

1995 GMC SIERRA
273,000 MILES • 5.7L • V8 • 4WD • AUTOMATIC
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STONEWALL41305
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  • 1 POST
I just replaced the transmission. This noise was happening beforehand, it is coming from the front of the tranny/ back of the motor. It sounds like a rattling sound, I dont think its the tranny due to it being a completely different one and the torque converter has been replaced as well. What could it be?
Mar 18, 2014 at 11:46 AM
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CARADIODOC
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  • 34,308 POSTS
A rattling or banging sound from that area is usually caused by a cracked flex plate. To find that you can often turn the engine by hand at the vibration damper, and the ring gear on the flex plate won't turn as much. Put a chalk mark on the ring gear teeth and the transmission case, then rotate the vibration damper a tiny amount and see if the chalk marks move the same amount. If you see a definite delay or difference, suspect the flex plate. Sometimes the broken parts get wedged together and you won't see that difference. Then you have no choice but to take it apart to inspect it. The breaks occur right around the six mounting bolts where it bolts to the crankshaft.
Mar 19, 2014 at 1:29 PM