VMAX7

My s430 has a low whining sound coming from the diff at cruising speeds? I wonder if this is normal or not?

02Drunkenup

Only under power right? I get it too... just too lazy to do anything about it.

VMAX7

I have 210k on the clock. I called around for estimates. $1,250 used, $2,500 new (installed). I sourced a used one for $350 but installation is unknown. I do not know how to install one of these but if anyone can point me in the right direction to a diy that would be appreciated.

xexpo

I would try replacing the fluid first.