87 V10, 4" lift, new 33" tires, 350, TH400, 10 bolt front, 12 bolt rear, 4.10s, rebuilt drive train (except transfer case), craigslist frankentruck.
Before I did much to this truck, I never heard too much noise out of the tires or the drivetrain- or even when I replaced the tires with a new set. Ever since I had the diffs rebuilt (along with the drive shafts) I now hear a mechanical whine coming from the truck- it sounds just like a police/fire/paramedic siren noise in the distance. I mostly only hear it when coasting, as the engine noise drowns most everything else out when on the gas. It also appears to change in pitch/frequency based on the transmission shifting- as in when downshifting coming to a stop the sound changes based on the gear/rpm.
Should this be normal?
When I am not paying too much attention to it my brain picks it up and I start looking for flashing lights because I think it is a cop or ambulance. Want to make sure I am not missing a sign of possible impending issues with my transmission or rest of the drive train. I am leaking a bit of transmission fluid- seems it is impossible to get that pan to stop leaking. Diff shop tells me the NP208 I have is a bit worn and recommends replacement, but with all the other money I have already sunk into the truck that is going to have to wait.