Humming/Whining noise when lifting foot off gas pedal to slow down

[stranger21ny]

Hi every one,

I have a 2008 Rogue SL with 145K. I went to my mechanic for something and he noticed a noise when turning and said I need a drive shaft replacement ($520 later) I bought it and they placed it. While I was waiting for the drive shaft to arrive, I noticed a humming/whinning noise when I lift my foot of the gas peddle to slow down ( ), but when I step on the gas the noise goes a way. It sounds like it's coming from the rear diff. I have replaced the fluid with no help. Any idea if I can get it fixed, or if I will need a new differential. The car is old and I'm thinking it's worth the $1700 for the differential plus labor. Or if anyone know where to rebuild diffs in New York City, I would appreciate it. Thank you!

[AZhitman]

AWD?

Not sure what differential that model has, but I can;t imagine it'll be a cheap replacement. 145k seems low miles for a diff to fail, so I'd want to diagnose further. Can you put it on a lift and run it? BTW, $520 for a DS replacement sounds high as well, but maybe that's a NY thing.

Coastdown diff noise usually means the lash is wrong (wear)... Honestly, I'd drive it until it fails, because unless you DIY it with a junkyard diff, it'll be expensive.

[stranger21ny]

Thanks for your input. its An AWD. yea it im sure its going to be expensive unfortunately.

[macgiver]

How has the new driveshaft affected this noise ? at all ?? Cause what your describing is what a bad
driveshaft will do from giving gas ,to coast , or during deceleration - as you mention.

But ,of course a bad driveshaft could have "concurrently" messed up the pinion bearing? Try 140W gear oil??
$8 temporary fix , you know.

p.s. Replacing just a pinion bearing, if all else OK is not exactly a "full" diff rebuild , probly 1/3 that $1700.
And when re-assembled & shimmed to specs - very likely be fine.

[stranger21ny]

Macgiver. Thank you for your input. i could not find any one here in New York that will rebuild or even want to disassemble the differential clad change the pinion bearing. looks like im stuck with either a $550-$700 used differential or a $1300-$1500 new one.