454SuperSport

rebuilt the rear in a buddys 99 t/a with an auburn pro, motive 4.10s, moser axles, all new bearings, and a solid pinion spacer. had a good pattern and 0.0075" backlash on the setup. he cruised it around town for a few days to break it in and they were quiet as can be, after about 150 miles they suddenly got some serious whine at a steady cruise. we tore it back down today and checked the backlash which is now 0.0085". everything looks fine, nothing came loose. anybody got an idea why they would suddenly get loud?

01ssreda4

iTrader: (96)

Yep, I would say its gear noise..... Just messing with ya, Did you recheck pinion preload before you pulled it apart. Maybe the crush sleeve loosened up. Some gears are just noisy. My Motive 3.73s did the exact same thing.

454SuperSport

its got a solid pinion spacer. the pinion preload did loosen up some but i'm pretty sure its just the new bearings seating in. whats really bugging me was that they were dead silent for a week and over 100 miles. he drove the car to work, and when he left going home they were making noise

dondb

iTrader: (1)

You set the pinion backlash....what was the preload on the pinion bearing? Did yo put the correct spacers in the pinion to get the desired pinion preload on the solid sleeve? Should be about 12 to 18 inch pounds.

454SuperSport

the pinion spacer was shimmed right, had about 25 in/lbs. on the initial setup with the new bearings. felt like about 10 in/lbs. today.

01ssreda4

iTrader: (96)

that sounds about right. I usually shoot for 25.