Rattling rumbling under light acceleration

[John Cunningham]

I have heard this noise in several GM trucks over the years. Its a light rattle rumble strip kinda noise under light acceleration. Instead me hanging under the truck while somebody drives ( dangerous) I thought somebody on this form would know exactly where this sound emits from.
I figure this might be safer than hanging upside down under the truck...
Thanks in advance and thanks for keeping me from going to the ER

 

[Kv5137kv5137]

I just started getting that also,, haven’t figured it out yet


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[Schimpfy]

I'm curious if your sound occurs similarly to mine. When I'm cruising between 40-45 mph, the tach's at 1K in 4th and there's a bit of load on the motor when I start climbing a mild grade is where mine happens. Higher RPMs, 3rd gear, <40 mph, >45 mph and cruising on flat road with no real resistance I've got no noise. It seems to be coming from somewhere around the back of the engine. My only guess right now is that cover plate on the front of the transmission vibrating at just the right resonance.

 

[Kv5137kv5137]

No only at light acceleration from start


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[randy fabian]

Check U-joint play/wear. Drive train noise is common at that speed and RPM

 

[John Cunningham]

I just started getting that also,, haven’t figured it out yet


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Just at light acceleration

 

[alpinecrick]

I have a rattle when the engine is fully warmed up, at a stop while in gear on my 96 K1500. I've had the truck up on the rack and checked everything I could think of, and so did the guys at the shop.

My WAG at this point is something in the CAT's or the muffler.

 

[Chevyguy78]

I have the exact same problem. its been doing it for about 2 years. It does it under light acceleration also.
I have been trying to figure it out forever and can not come up with anything. It is progressively getting worse. still same noise....