Hello. I have a 1992 Jeep Cherokee 5-speed manual 4.0 l. It has started making a loud howling/humming noise is the best way I can describe it, and the noise occurs when I am in gear and letting off the gas as soon as I press the gas the noise stops. I can't pinpoint the exact location but it sounds like it is somewhere up front by the passenger side from me being inside the cabin. If anybody knows what it can be please let me know. Like I said the noise occurs while I'm driving in gear when I let off the gas. I checked the fluid in the transmission which was fine also my rear end was fine both full with fluid. Can someone please let me know what it possibly could be. Also the loud humming / vibration type noise happens in all the gears when I release the gas pedal as soon as I press the gas pedal it goes away and sometimes if I press the clutch in the noise goes away and sometimes I push the clutch in and the noise doesn't go away

 

Most commonly this is pilot bearing

 

Oh really, than you for your response. I will look into it.

 

Pilot bearing/bushing only makes noise when the engine and input shaft of the trans are at different speeds. Never in gear driving down the road.

 

I'm not sure where that info comes from but that wasn't my experience when mine did the same thing. If the bearing fails then the shaft alignment is lost and it makes noise all the time. If its only partially failed then it may only whine when the speeds differ

 

Well yeah, if it's blown to hell, yes. But is that what the OP is describing?

 

When he clutch not pressed in, the pilot bearing isn't turning with respect to the input shaft and doesn't make noise. If the pilot is completely trashed, it can take out the main input bearing. I had that happen to me. It started out real noisy when pushing the clutch in and eventually seized up and stalled the engine with the clutch pushed in while stopped.