What happens when the rear differential oil gets too old and needs to be changed? Does the car still feel the same or are there any changes that affect performance when the oil is old?

 

Good question. I'd say by the time you hear/feel something you may already have damage. Change it now, it's not expensive or difficult -- I did mine just a month or two ago. Or are you already having problems? If not, just do it my mileage, at the recommended interval.

 

I just started noticing that the car feels like its not putting the power to the wheels. It doesnt accelerate like it used to. My mechanic checked the fluid and said it needs to be changed so im getting that done this weekend. Hopefully that will fix the problem!

 

^ What mileage?

 

53k

 

check the screws in ur head thats prob it.

 

I got the fluid changed and the car feels a little better than before but the problem is still there. Do you guys think the gears are damaged?

 

Did anyone look at the fluid, or analyze it? Only way to know for sure, really. And are you sure the problem is in the diff? You may have to pony up for a thorough inspection by a competent mechanic.

 

yea my mechanic saw the fluid and was like "wow there is much metal." The fluid was almost metallic silver/black. The magnet had a lot of metal shavings on it too.

 

It's actually sorta normal for the magnet to have a fair buildup...but if the 'shavings' were good-sized, you may want to have your mech take a closer look at the diff itself. Just my semi-educated opinion.

 

yea the shavings were a decent size. Yea im gonna need him to look into it. Could anything else be causing that problem though, like the transmission? The trasnmission was replaced under warranty about 22k miles ago by Infiniti so i dont know

 

If you had any metal pieces in the fluid that were not simple shavings that resemble graphite, then you might have damage to the ring/pinion.


I dont see how the transmission could have much effect on the differential....but its possible.

 

i was driving on the highway today and i was going to change lanes and stepped on the gas, but the car wasnt accelerating much so i pushed a little harder on the gas and heard a big "thud" sound from under the center console and the car got into gear and started accelerating a little faster with some lag. Im assuming that sound came from the transmission when it was going to change gears? Car feels so sluggish under acceleration.