[blu96gm]

I have a 4.3 5 speed and when I'm in low rpm something under the truck rattles. But when I drop the gear or once I've reached a certain rpm(about 2500) it stops. What could it be?

I appreciate the help thanx.

 

[Whifflebat]

How low of RPM? My old volvo rattled when you lugged the engine... If not that, then it could be alot of different things. Where under the truck?

 

[blu96gm]

I'm thinkin at around 2000 and it comes from somewhere in the middle of the truck or towards the back undercarriage.

 

[chevyman992002]

i get a vibration out of my 4.3 right around 1100 rpm. it's always been there, so i dont worry about it.