Drivetrain Noise

[rage707]

Hey All,

I have a noise coming from the drivetrain. It happens when I let off the gas. It sounds very similar to the popping and burbling of the exhaust so its tough to pinpoint where its coming from. It happens on the highway and at slow speeds and the sound slows down as I slow down. It kinda vibrates the floor, anyone got any ideas?

Thanks

 

[trinity_gt]

Exhaust rubbing on the driveshaft at all?

 

[rage707]

Nope, Any other ideas?

 

[trinity_gt]

Well, if it's only audible on the overrun (i.e. when the drivetrain is loaded opposite to the way it is when you're accelerating) then about the only thing it can be is the front pinion bearing. During acceleration, the meshing action of the hypoid gears tends to push the pinion out of the diff housing, loading the rear bearing. When in overrun, the front bearing is most heavily loaded. If the noise is only there when that bearing is loaded...

I thought perhaps the exhaust was touching the driveshaft if an engine mount was weak allowing the engine to rock excessively, drawing the driver's side muffler toward the driveshaft, when loaded in overrun.

 

[rage707]

That sounds possible. It does happen only when I let of the gas. It happens more once it gets warmed up. Its like a rubbing sound in the rear that vibrates the floor and slows down as the car slows down. It gets worse when I hit the brakes when Im coming to a stop. If it is the pinion bearing, would it be covered under warranty?

Thanks a lot

 

[trinity_gt]

Assuming the bearing is defective and assuming you've not done any mods that would otherwise affect it and assuming the car is still in the drivetrain warranty period, sure, I would think it'd be covered.