Humming/Slight Vibration Front End - Help!
So, here's my issue. I have a 1999 Jeep Grand Cherokee Limited with a 4" Rough Country lift. I bought it from a friend and immediately noticed a slight vibration and a weird humming sound in the front end that I could control whether it was there or not by the gas pedal. Let off the pedal and it went away, barely touch the gas and it returns. It came and went in intensity when the suspension flexed, so when the suspension sank it mostly, if not all, went away. When the suspension rose (like on the highway and the vehicle rises when driving as the road surface fluctuates) it intensified or came back.
Brought it in and a 4x4 shop said it was the pinion bearing, so I had them change it and all the seals in the front end. Sound is still there, but the tone has changed so I do believe the pinion bearing was bad. Next they said the front driveshaft needed to be rebuilt (specifically the cardan joint) so I had that done. The sound is still there. It's a low, humming type sound you can only hear at speeds of about 45 or greater. It increases in sound the faster I go. The wheel bearings/hubs are new. I can still mostly control the sound with the gas pedal.
Could the bad pinion bearing have caused the ring and pinion gear to have changed wear pattern to the point that it's now making noise? I'm going to pull the front driveshaft and drive it and will repost to let everyone know if the sound goes away.
Any help would be great!