Join Date: May 2004
location: Morganville, NJ
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The whine, when it's present, is from the differential. Or more specifically the drive gear to the "ring" gear that drives the differential. If there is any play in the carrier bearings, it can move side to side slightly. Even .001" is enough to cause issues.
On normal acceleration and loaded driving, only one side of the gears are in full mesh. When you coast or decelerate, the load it placed on the opposite side of the teeth.
If there are any issues in tooth mesh (backlash, which is the play between the gears) too tight, too loose or loaded on one side or the other, you get noise. I hear this noise VERY frequently in Civic autos AND manuals with higher mileage.
Redline D4 or D6, can possibly reduce this noise as it's a GL4 gear oil rated fluid. It can "cushion" the gear to gear contact way better than Z1.
If you've ever heard a conventional rear drive diff with tooth contact issues with the ring and pinion gears, you'll never forget it. Usually at 45-50 under constant throttle they will "scream", release the throttle and it's silent. Back on the gas and the scream returns. If there is play in the pinion bearings or diff carrier bearings, they yowl on deceleration.
Sapphire blue '04 V6 6 speed w/ full HFP, comptech ss, momo shadow, TL-S 27.2h/20 bars, intake spacer, retro chrome MH1 HIR2 highs, hella DE fogs, EBC Ultimax, subwoofer/amp, infinity rears, HD Radio, aux adapter, navi conversion.
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