I will chime in here
From direct experience if you have a bad axle bearing chew up an axle, the debris can damage the pinion bearings and/or carrier bearings. This does not always have to show massive wear on the axle, the material can come from the axle bearings instead.
You replaced your axle bearings and still hear noises yes??
In my case I could move the carrier back and forth by hand, a good sign the bearings were shot. After removing the axles I could also move the carrier up and down. Could have just replaced the carrier bearings but.. Unit also whined, the ring had been deflecting from the pinion gear during turns (with an awful sound to accompany) so the wear pattern was getting damaged. Plus the pinion bearing was probably wiped too, it would make extra noise under coasting probably from the pinion shaft deflecting. So this would need a full ring/pinion gear, all the bearings, axles and axle bearings...
Instead of a full housing rebuild I got a used unit.
Just replacing the pinion bearing is probably not going to do it. You may have similar damage to the rest of your axle housing.
Since you can use a 03 - 09 unit I would recommend finding a nice low mile newer axle housing. I got one rusty and 95K miles as it had 3.55 gears and Trac Loc. I could have gotten a nicer one with 2.73 open rear but well...
Edited by Chevyguy (12/27/08 08:19 AM)
M79 104K miles Jmod!! Lidio 93 tune for the track BOC 91 octane street tune 14.85 @95.632004 Crown Vic LX
145K Silver Birch Light flint leather FMX1 04 P-71 PCM swap 70 mm TB Custom shorting wire harness. 28/ 21mm MM swaybars Monroe severe duty shocks. Marauder subwoofer and painted cap heated mirrors. NEED DUAL EXHAUST
Project car 74 Chevy Laguna type S-3, # match 400 SBC
93 P-71 2001 P-73, 94 TC Exec, 96 TC Signature