Hello. 1999 Blazer, 2wd, replaced both rear axle shafts and bearings and seals; had differential fluid leaking onto brakes. Now I hear a roaring at about 45mph which gets worse with acceleration; no vibration. The one axle shaft was really worn down and there were shavings in the fluid and on the cover/magnet. I probably should have replaced the whole differential. Any comments? pointers? what's the worst that can happen if I keep driving?

 

Assuming the noise is from the rear end, and if you had metal shavings in the fluid, it could be pinion bearings, side bearings, or ring & pinion.

 

Thanks, can it seize up? while driving; there is no vibration at this time; what is the worst that can happen. Don't want to go back in it right now,,,

 

Any one of those possibilities could cause it to leave you stranded. The warning sounds are there!