I have a knocking metal popping sound from the rear passenger side of the car sometimes it sounds like the front of the car...anyway the dealer siad my rear diff was out Desert Honda wants $5400.00 to fix it ! I also took it to Asian imports here in Vegas ..CLUELess they couldn't figere out the promblem and I took it to another Honda dealer before that they didn't know what the sound was...
How do I know for sure if the rear diff needs to be replaced? The cracking metal knocking sound happens when I turn my steering wheel left or right and when I brake..I thought it would be my rear axel does anyone have the same issue with their car?

 

This should prob be in under the hood

If your diff is bad most likely it wont matter if you turn to the right/left.

 

How many miles on the car? sounds like axels maybe. You can drain the oil in the diff and look at it to see if there is an add nominal amount of metal in the fluid. $5400 is crazy for a rear diff, you can buy a used one for $500 to $700.