T56 noise at low rpm
#1
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Location: Des Moines, IA
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I have had my car for a few months now and just noticed that when I'm in the 1500-2500 rpm range it sounds like a rattling noise coming from the rear of my trans, and its mainly when I'm decelerating. I changed the trans fluid over the weekend, it shifts smoother but the noise is still there. Is this noise normal? Someone please help!!!
#3
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IMO, that noise comes from excess mainshaft clearance due to normal wear. I recently rebuilt my T56 and tightened the main shaft clearance and it no longer has the low RPM rumble or pea gravel in a box sound. This is not an easy adjustment and requires disassembly of the tranny.
#4
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Mine does a similar noise in 4th from 1000-1500 rpms, sounds like gravel bouncing around in the trans. I just rebuilt it and put preload on the main and countershafts, and some end play on the counter extension. I just figured it was the counter and extension shafts making noise since there is no load on them. I've tried cheapo Valvoline ATF, M1 synthetic ATF, and Pennzoil synchomesh, same sound with all three.