"Planetary gearset noise" any suggestions or ideas?
08-01-2006, 03:35 PM
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Loud, unusual tranny noise. Any suggestions or ideas? Have an unususal noise from the rear of the car (or so I thought). It sounds like a dragging brake or a vacuum leak, but is strictly MPH related (not RPM). The faster one goes, the louder it gets, and in coast or drive, and engine off or on, it stays the same.
By putting the car on a lift, and running and in gear, the sound seems to come from THE MIDDLE OF THE DRIVESHAFT, and it is LOUD! Further inspection sources it to the rear of the transmission. A GM tech who knows these cars said it sounds like the planetary gearset, but it is apparently not. I just had the differential pinion bearing replaced, but can't understand how a once quiet tranny would cause such a noise all at once. A pan inspection showed normal wear debris and no bearing or bushing residue. The car has 86K miles and is stock and not abused.
Aside from the noise, which is rather loud at 60 MPH, everything else is as normal. I don't want to have the tranny exhumed and autopsied unless necessary and the tech suggests living with the noise...
Any ideas, suggestions, similar experiences???
Thanks.
By putting the car on a lift, and running and in gear, the sound seems to come from THE MIDDLE OF THE DRIVESHAFT, and it is LOUD! Further inspection sources it to the rear of the transmission. A GM tech who knows these cars said it sounds like the planetary gearset, but it is apparently not. I just had the differential pinion bearing replaced, but can't understand how a once quiet tranny would cause such a noise all at once. A pan inspection showed normal wear debris and no bearing or bushing residue. The car has 86K miles and is stock and not abused.
Aside from the noise, which is rather loud at 60 MPH, everything else is as normal. I don't want to have the tranny exhumed and autopsied unless necessary and the tech suggests living with the noise...
Any ideas, suggestions, similar experiences???
Thanks.
Last edited by emarkay; 08-02-2006 at 12:43 PM. Reason: More info.
08-07-2006, 01:50 PM
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Originally Posted by Predator T/A
i think it is coming from the rear they may not have set the backlash or pinion bearing preload right or maybe just didnt set it up right at all
https://ls1tech.com/forums/showthrea...88#post5311388
