My 1985 Chevy S10 4x4 2.8 is making a roaring sound when I'm accelerating but goes quiet when I ease up on the pedal and coast - it is very noticeable - I just had my front wheel bearing replaced because my mechanic said that it needed it - this did fix some noises but not this one
If your truck has a thermostatic clutch on the cooling fan, it's possible that the clutch isn't operating properly. When mine failed, I got the same effect you're describing.
Standard Tranny or Automatic..
if Standard Tranny Check the oil in it
Also RUSTED out Body mounts .. Body is Sitting on the Tranny
This is an automatic and I would say the noise is coming from the back but it's hard to say - it seems to drive fine
check the GREASE in the REAR END
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.