: Another Rear End Post - Something blew up on me



04 Cadillac CTS-V
07-14-13, 07:05 PM
OK, so I have read the stickys and several other posts before and after buying my 04 cts-v 2 weeks ago.

After I bought it I had the rear diff bushing replaced as there was some slop in the driveline... The shop recommended it to fix the clunking and it jived with the forum posts/stickys.... So a decent amount of money later I am enjoying my new purchase. Thursday and Friday the clunking came back when shifting and slowly got more noticeable. It also developed a noise in between acceleration and deceleration when in gear and the same level if not louder when not in gear IE when not under load. I called the shop Saturday morning - they said they did not have time for me that day, bring it in Monday.

In the middle of changing the oil in my other car, I find that the wrong oil filter was in the box... Take the Cadillac to get it from the parts store. Pulling out of the store onto a 2 lane highway and shifting under what I would consider standard load for getting onto a fast moving road and immediately heard a loud bang and loud rumble. So 2.5 hours later the car is towed to the shop, and at least they give me a free ride home - but now I am sitting here scratching my head wondering what is wrong and how much it is going to cost me. I hate to say it for the shops sake, but I kinda hope they made and admit to making a mistake which caused the issue and it is covered.

There was a piece of metal, looked like from a gear which was conical (IE not a spline) which I discovered on the ground near the car... May or may not have been from my car, leaning towards yes though. There was not any fluid leaks.
In Neutral - Running no issues motor starts and runs fine.
When you put it in gear, even with the clutch in, a terrible grinding noise started.
When you roll the car forward (off and in neutral) same/similar terrible grinding noise.


IDEAS?!? :confused:

Becker
07-14-13, 08:18 PM
sorry to hear that man :/ I hope experts chime in with some good advice

HAMSTAR
07-14-13, 08:28 PM
Looks like you lost your diff. Congrats, you get to buy an 8.8.

philistine
07-14-13, 08:55 PM
Yeah sounds like your differential. Man I thought you were gonna say what you had for lunch that day the way your post was going.

***Edit*** I'm replacing my driveshaft, axles, rear-end next weekend. Hit me up if you're interested but for what it's worth...I'm taking my stock stuff off and replacing it with the CS 8.8" kit.

Andringa
07-15-13, 12:30 AM
When you put it in gear, even with the clutch in, a terrible grinding noise started.
When you roll the car forward (off and in neutral) same/similar terrible grinding noise.


IDEAS?!? :confused:

Are you saying that there is a grinding noise with the engine running when the trans is in gear but the car is stationary?

If you have a grinding noise and your car isn't moving then it shouldn't be the diff. The only way that would be possible is if your diff is broken and your clutch is failing to completely disengage.

With the transmission in gear and the clutch pedal pushed in, nothing behind the clutch should be moving.

04 Cadillac CTS-V
07-15-13, 01:31 AM
Correct. Even when not moving.... hope its not more than one thing wrong....

My thoughts about diff.... wouldnt there be fluid leak if a piece of metal came out? Im used to solid axles so this logic could be way off.
It almost sounds like the drive shaft might be part of the issue? thought about the clutch, but how would that cause grinding when off? Forgot to mention car being in gear and off didnt stop rolling.

I didnt get lunch, left out not having my cell with me, and walking uphill both ways back to the autostore to use their phone...

Thanks for the feedback, i am no expert so im thinking out loud, no saying you guys are wrong..
one other thought... snapped cv joints/axles? Clutch worked fine before incident, my history has been with clutches going out slowly.

Andringa
07-15-13, 03:51 AM
A snapped CV or axle fits except for the grinding while stationary.

Good luck, hopefully the shop has it figured out for you in the morning. It should be very obvious once it is up on a lift.

heavymetals
07-15-13, 04:17 AM
"Forgot to mention car being in gear and off didnt stop rolling."

WTF does this mean?

If it makes noise and isn't moving, it isn't the diff.

Sounds to me like the transmission input has gone funky or pressure plate , if it isn't "rolling".

If it makes the noise when rolling then could be anyone of the rear components.

You should be able to jack it up and spin stuff (even motor assisted) to find what's gone bad.

04 Cadillac CTS-V
07-15-13, 05:19 PM
Well shop thinks at least a driveshaft.... How likely is it that an improper bushing install could have caused the shaft to snap?

RyRidesMotoX
07-15-13, 05:33 PM
Well shop thinks at least a driveshaft.... How likely is it that an improper bushing install could have caused the shaft to snap?

Well putting the wrong bushing in there could lead to binding. But I would thing that the bushing would break before the driveshaft would. I mean you're talking about a poly or rubber bushing vs a driveshaft. Maybe the pinion angle was changed??? Can it even be changed in a V with an independent suspension? I know in off road trucks I have helped with, the pinion angle was fairly crucial so you didn't get any binding in the driveshaft and crack the diff case of break a driveshaft or something of that nature.

Andringa
07-15-13, 06:12 PM
If you want us to try to guess what happen to it, it would help to have pictures of the driveshaft.

The driveshaft is normally disconnected from the pinion when replacing the diff bushing, so I wouldn't be surprised if it was related. The driveshaft alone doesn't account for some of the other things you were describing. Especially the noise when you have the clutch pedal pushed in and in gear.