I have been investigating a whine (possibly transmission or rear diff.) and was curious if there was a good place to start (common bearing or somthing that would cause whine while in motion). If there is how do I go about checking it? I have a 97 impreza L 2.2 MT with aprox. 163k.

Congrats 1st for that is a good package. Check the rear fluid 1st. Mine was a '97 Legacy and while all other levels were topped etc. The rear diff plug was so frozen it was like it had never moved in 10 yrs. So a good refill of that.

The other whine is between the two drives and has something to do with the center bearing possibly.

I have been investigating a whine (possibly transmission or rear diff.) and was curious if there was a good place to start (common bearing or somthing that would cause whine while in motion). If there is how do I go about checking it? I have a 97 impreza L 2.2 MT with aprox. 163k.

 

Whine or hum?

 

Changes when you turn?

 

Changes when you are on/off the throttle, or at just the right throttle setting to take the load off the transmission?

 

 

Dave

Whine or hum?

 

Changes when you turn?

 

Changes when you are on/off the throttle, or at just the right throttle setting to take the load off the transmission?

 

 

Dave

 

Turning does not affect it. You tend not to hear it under accl. When you come off the throttle you hear it in all gears, but I have found that it is most pronounced at a little bit higher speeds. The other reason I thought rear diff was that my FSM said something about excessive backlash. When I am at constant throttle (not accelerating or decelerating) the car will sort of jerk back and then forward again like its hard for it to maintain a constant throttle. The FSM said that the side pinion or ring (not sure at the moment, i don't have it in front of me) in the rear diff could be going out and to fill oil to recommended level.

rear diff failures in subarus are rare, but since it's not a bad idea to change the rear diff fluid once in 163,000 miles , that's probably not a bad thing to do. keep an eye on fluid color and consistency as it's coming out and how much comes out. then refill.

 

can you tell if it's front or rear?

 

front diff issues are far more common, though of the multiple i've personally seen i've only seen it on EJ25's.

rear diff failures in subarus are rare, but since it's not a bad idea to change the rear diff fluid once in 163,000 miles , that's probably not a bad thing to do. keep an eye on fluid color and consistency as it's coming out and how much comes out. then refill.

 

can you tell if it's front or rear?

 

front diff issues are far more common, though of the multiple i've personally seen i've only seen it on EJ25's.

 

I changed the rear diff oil the other day, that stuff smells terrible. It seemed pretty low when I pulled the top plug I could barely touch the oil with the tip of my finger, so it was definitely a good way below that top filler level. There was a little bit of bronze flakes in the fluid, and the standard fine metal shavings on the magnetic plug.

 

It seems to drive a little smoother after the oil change, but it did not affect the gear whine at all.