From: IAN.MOORCRAFT(UK)[email protected]
Date: 28 Feb 2001
Time: 08:26:16
Remote Name: 213.1.151.111
Greg, I`m not sure if a Big 7 is the same as a 7 (I have never rebuilt one), The backlash on a 7 is 1/16" rotary movement at 7" distance from the centre of the pinion shaft, make sure that the freeplay is between the crownwheel and pinion only and not also the play between the planet gears and the end of the half shafts, Has a Big 7 got a oil drain plug in a position where you can wedge the crown wheel still?, but watch that you don't preload it against the pinion, thus giving a false reading. You don't say if the rumble is at all times or, only on drive or overrun. If it is at all times suspect too little backlash, If on drive only may also be too little backlash, If on both drive and overrun suspect worn or incorrectly adjusted pinion shaft bearings. Also on a 7 the torque tube socket can give all kinds of harmonics, but I think a Big 7 has a "silentblock" fitting like a Ruby, even so give it a good check for any metal to metal contact. Regards Ian