Have a 96 blazer with a whine in the front end and have replaced both hib and yet the noise persists it starts around 20 or 30 mph I have read about some 4x4 switch I need to test ...how do I go about doing this

 

does it do it at idle,when you rev the engine? Could be a pulley too. Pull the belt off. spin the tensioner and idler pulleys. if they are gritty replace em. friend had a car that made a noise,but not at idle. under load his idler pulley would whine.

 

No its deffinately in the front end somewhere motor is smooothhhh

It sounds like a hub does when its bad but its not the hubs lol

Also when I engage the 4x4 I beleive the whine/grind continues I will check tonight

 

How are your cv shafts? Mine are noisy but I have just grown used to it If you have a torn boot and there is no grease left in there they can be really noisy just like a bad hub.

 

I can feel the noise through the floor idk how I would go about checking if there good or bad without just droppin the cash to replace them my only worry is im going on a 600 mile trip this weekend and I know my pretty little 150k mile vortec will make it but that noise worries me