Hello everyone. I just had brand new 2inch Fabtech leaf spring shackles installed along with a 1.5 inch torsion bar crank and now i have a humming noise at around 30 mph. My mechanic says the noise is minimal and that it will cause no harm. Is this true, and what could cause this and how could it be fixed. Thanks.

 

my truck did this too never corrected it still does it...

 

What you have done is changed the harmonics of the driveline-thats all! Keep grease in the joints! and watch for balance problems...

 

Ok, thanks guys. But what do you mean by checking for balance problems.

 

Humming from the front or the back? If it's from the front the tires could be cupped and when you cranked the T-bars it changed the camber angle, so you may be able to feel it now.