Loud hum from what?

[xLibelle]

i had a friend mechanic listen to the video and he was certain that its the gears in the diff due to worn bearings. bearings dont make quite that sound as the ring will.

[accident]

definitely sounds like the e30 diff whine. My friend's car and his brother's race car both do it.

[xLibelle]

i just got two more LSD's in the last couple weeks, a 4.10 and a 3.91. I will try them out to see what changes

[rcfanatic]

Did you ever find out what was causing the hum?

[xLibelle]

Wheel bearing. Forgot to update this thread... though still not done with the fix.