My 2008 possible issue with rear differential

[v10CodeMonkey]

So in the past month I've noticed some oddities while driving my stock 08. I occasionally feel a slight "thump" against the back of my seat and an almost "floaty" feeling when turning, like my seat is sliding ever so slightly (it isn't, it's firmly attached). I only notice this at slower speeds. No "clunking" when shifting or anything or any other noticeable behaviors. Got it up on jacks and took a look underneath and noticed the driveshaft has probably about 1/2 inch of play in it, is this normal? Changed the differential fluid for the first time (7000 miles) and noticed some sand sized pieces of metal in it along with very fine dusting of metal that gave the fluid a milky appearance in places. Is my differential toast? I don't know if it's related, but these oddities didn't appear until after I drove over a rough patch of road at a higher rate of speed. Similar to going over railroad tracks too fast, banged the car around pretty good. Any ideas or anyone noticed similar behaviors? About to put the car away for the winter but hoping to at least have something to go on so I can start planning a fix during the winter or early spring.

[ViperGTS]

...sand sized pieces of metal does not sound good in a transmission/differential...

[Dan Cragin]

So in the past month I've noticed some oddities while driving my stock 08. I occasionally feel a slight "thump" against the back of my seat and an almost "floaty" feeling when turning, like my seat is sliding ever so slightly (it isn't, it's firmly attached). I only notice this at slower speeds. No "clunking" when shifting or anything or any other noticeable behaviors. Got it up on jacks and took a look underneath and noticed the driveshaft has probably about 1/2 inch of play in it, is this normal? Changed the differential fluid for the first time (7000 miles) and noticed some sand sized pieces of metal in it along with very fine dusting of metal that gave the fluid a milky appearance in places. Is my differential toast? I don't know if it's related, but these oddities didn't appear until after I drove over a rough patch of road at a higher rate of speed. Similar to going over railroad tracks too fast, banged the car around pretty good. Any ideas or anyone noticed similar behaviors? About to put the car away for the winter but hoping to at least have something to go on so I can start planning a fix during the winter or early spring.

On your first service you will see some shiny metal residue from the break-in process, sand sized pieces could indicate a problem but sometimes you get some little casting flash or other metal that may not be an issue. On the 08's we had quite a few rear ends that needed friction modifier added to get rid of a "grabbing" condition. I would try that first.

[08viperviolet]

I have had 3 gen four cars and all of them they needed to add the friction modifier. It was all for noise on slow turns that are sharp. Hope that is all you need to do. Good luck.

[v10CodeMonkey]

thanks for the reply's everyone. When I changed the fluid I used Royal Purple with added friction modifier so maybe that will help clear it up. I'll drive it a little more and see if anything changes.

[lmcgrew79]

Maybe dodge/mopar synthetic gear oil with there friction modifier.

[TexasTonka]

Instead of starting new thought I would jump on this one. Got a new to me '09 ACR. Was getting the 'clunk' turning right so flushed diff with oem fluid and friction modifier. Actually flushed it with a fresh quart then added the 1.5 quarts and modifier. While belly plate was off we flushed trans fluid too with oem fluid. Did notice about 1/2" play in drive shaft before it would catch, seemed like a lot to me but don't have a comparison. We did also tighten all diff and trans mounts while belly pan was off. None were loose. Diff fluid flush and some figures 8 driving to lube up the diff took care of diff 'clunk' while turning right.
Just got the car and it's been raining so no launches or anything like that but taking off from lights shifting mainly from 2nd to 3rd and 3rd to 4th when letting clutch out to engage gear I do get a small thud before the gear bites. My old Twin Turbo GTS did this as well but had a modified diff and trans. This acr has never been touched.

It has 12k miles on it, so is it just age? My old acr had 500 miles on it and was tight on shifts with no noise.

The he clutch also seems to moan a bit starting out in first from a stoplight.

Any ideas?

[cubican]

Well if you ever need a replacement rear end I have one with a quaife in it.

[TexasTonka]

Well if you ever need a replacement rear end I have one with a quafe in it.

What gears? Direct drop in for a Gen IV?

[cubican]

yes i have the complete rear end with amzoil in it. Fresh rebuilt no miles on it gears are the stock 3:07. i also have a 2009 with 355 used but that one has some miles on it and like yours it has some play on the gears. If your tracking your car your the rear end is a time bomb once they have some play on the gears. For normal driving is ok to have some play on them the quaife has no play at all.

[TexasTonka]

yes i have the complete rear end with amzoil in it. Fresh rebuilt no miles on it gears are the stock 3:07. i also have a 2009 with 355 used but that one has some miles on it and like yours it has some play on the gears. If your tracking your car your the rear end is a time bomb once they have some play on the gears. For normal driving is ok to have some play on them the quaife has no play at all.

Message me a price Pedro, Interested. Not sure if Maxcare warranty will cover this.

[cubican]

LOL, the toys just get more expencive as we get old. i will pm you the details.