VMethos
09-04-2008, 09:15 PM
Ok... so, I've seen that it has been a fairly common problem in the past, (several pages of documentation that you can read HERE (http://forums.nasioc.com/forums/showthread.php?t=103494) if you want) but just wanted to see if anyone else had any additional input.
MConte and I were discussing similar problems in this THREAD (http://www.dirtyimpreza.com/forums/showthread.php?t=5893&page=5), but it probably should be placed in its own thread here.
Anyways...
The problem is this:
--The car makes a whining/grinding noise while decelerating in gear
--The noise is related to road speed and does not alter due to gear selection or rpm
--The whine is very faintly there while in neutral
--There is NO noise while idling at a stop or from pressing in the clutch pedal
--There is NO noise during acceleration
So, I took it to the Subaru dealership and was told that the center diff (viscous coupler as the mechanic called it) probably needed to be replaced. My car has about 75,000 miles on it... but I have run it pretty hard in the snow and dirt, so it could be a possibility.
After reading through a fair bit of the first linked thread and thinking about it, I'd like to exhaust some other possibilities before swapping in a new center diff.
I am running tire pressures of 39/35 now, which only very slightly if at all decreased the volume of the decel noise. (I was previously running 39 / 38 )
And I put in a Lightweight Exedy flywheel (13.9 lbs approx) about a year and 15,000 miles ago when I replaced the clutch with the OEM Exedy clutch kit. But this noise didn't start occurring until about a little over a week ago. At that time I also replaced the transmission fluid with 1 Qt Redline Lightweight shockproof and approx. 3 Qts Redline 75W90.
This weekend I plan on replacing the transmission fluid and checking out any joints or bearings on the driveshaft, as well as my CV boots and axles as I thought there might have been an excess of grease near the front passenger axle when I looked at it today (which could be an unrelated issue... that the dealership didn't notice or mention)
MConte's problem was apparently resolved with changing the tire pressures and keeping his heat shield from rattling against his front skid plate.
I'll keep this updated if I figure anything out.
MConte and I were discussing similar problems in this THREAD (http://www.dirtyimpreza.com/forums/showthread.php?t=5893&page=5), but it probably should be placed in its own thread here.
Anyways...
The problem is this:
--The car makes a whining/grinding noise while decelerating in gear
--The noise is related to road speed and does not alter due to gear selection or rpm
--The whine is very faintly there while in neutral
--There is NO noise while idling at a stop or from pressing in the clutch pedal
--There is NO noise during acceleration
So, I took it to the Subaru dealership and was told that the center diff (viscous coupler as the mechanic called it) probably needed to be replaced. My car has about 75,000 miles on it... but I have run it pretty hard in the snow and dirt, so it could be a possibility.
After reading through a fair bit of the first linked thread and thinking about it, I'd like to exhaust some other possibilities before swapping in a new center diff.
I am running tire pressures of 39/35 now, which only very slightly if at all decreased the volume of the decel noise. (I was previously running 39 / 38 )
And I put in a Lightweight Exedy flywheel (13.9 lbs approx) about a year and 15,000 miles ago when I replaced the clutch with the OEM Exedy clutch kit. But this noise didn't start occurring until about a little over a week ago. At that time I also replaced the transmission fluid with 1 Qt Redline Lightweight shockproof and approx. 3 Qts Redline 75W90.
This weekend I plan on replacing the transmission fluid and checking out any joints or bearings on the driveshaft, as well as my CV boots and axles as I thought there might have been an excess of grease near the front passenger axle when I looked at it today (which could be an unrelated issue... that the dealership didn't notice or mention)
MConte's problem was apparently resolved with changing the tire pressures and keeping his heat shield from rattling against his front skid plate.
I'll keep this updated if I figure anything out.