: just picked up a 2005 cts v with 92k, i have questions...



4DoorZ06
03-26-13, 10:48 AM
I just picked up an 05 v with 92k miles. The car seems to be in great condition except for a clunking noise when I shift hard and also a slight rubbing noise coming from the back when I'm turning. Im.not familiar with this car so i need the help. Is there anyone that can tell me what this can be?

darkman
03-26-13, 11:08 AM
The clunking noise is probably a worn differential bushing although there are other posssibilities such as motor/transmission mounts.

If noise when turning sounds like "chatter" the differential fluid needs changed. The limited-slip differential has clutch packs which require the fluid to have a certain friction coefficient and the GM fluid deteriorates over time. If it is not chatter check for a tire rubbing the fender well.

As general matter this vehicle is very senesitive to fluid condition. If I were to buy a used one, I would flush/change/bleed every system in the car including coolant, motor oil, transmission, differential, power steering, brake fluid, and clutch fluid.

V user
03-26-13, 11:09 AM
Well I would climb under your car and inspect the driveline a common problem is a worn carrier bearing
from what I have learned from searching the web.
Also look a your flex couplers. After spending a day researching fixes for the driveline you can either replace it with a OEM, aftermarket or find a great speed shop that will cut off the old staked yolk and weld and
true a new one that you can service and replace the carrier bearing.

4DoorZ06
03-26-13, 11:30 AM
The noise sounds more of like if something was rolling in my trunk. I'm not much of a mechanic and have much to learn about this car so im just going to take it to my mechanic to change all the fluids and see if there's anything wrong with it. Are the motor/tranny mounts expensive?

izcain
03-26-13, 11:33 AM
Changing all the fluids will get someone looking over the car and they will probably find the issues anyways if you give them a heads up while they are performing the tasks. I always look a car over in my bay really well as small things like fluid changes are being performed. It also will give you a good baseline for the car and you will be able to tell alot about the car (wear of items) to find out where you will need to spend your time first.

rand49er
03-26-13, 11:41 AM
The clunking noise is probably a worn differential bushing although there are other posssibilities such as motor/transmission mounts.

If noise when turning sounds like "chatter" the differential fluid needs changed. The limited-slip differential has clutch packs which require the fluid to have a certain friction coefficient and the GM fluid deteriorates over time. If it is not chatter check for a tire rubbing the fender well.

As general matter this vehicle is very senesitive to fluid condition. If I were to buy a used one, I would flush/change/bleed every system in the car including coolant, motor oil, transmission, differential, power steering, brake fluid, and clutch fluid.^^^ Yeah all of that.




The noise sounds more of like if something was rolling in my trunk. I'm not much of a mechanic and have much to learn about this car so im just going to take it to my mechanic to change all the fluids and see if there's anything wrong with it. Are the motor/tranny mounts expensive?The differential bushing is probably the first one to attack. Call Luke at Lindsay Cadillac (see ad on right side of screen) for a replacement. Not too expensive either the part or the labor to change out.

Have your mechanic do a visual inspection of the motor mounts. Leaking fluid on one or both is a sure sign of a problem. There are several options for new MMs, and labor will run you a bit more than the diff bushing.

Trans mount could also be a suspect. Several options, not overly expensive, and labor to change isn't outrageous.

Don't change out anything you don't have to. Let your mechanic (assuming he's/she's reputable) be your guide, and you'll have many years to enjoy your new-to-you car. Congrats!

4DoorZ06
03-26-13, 11:55 AM
Thanks I appreciate the info! Now.talking in fluids. What type do I need for transmission, differential, engine, clutch etc.

darkman
03-26-13, 12:22 PM
Thanks I appreciate the info! Now.talking in fluids. What type do I need for transmission, differential, engine, clutch etc.

If you were going to do it all yourself I would get the various fluids from Amsoil. If you are taking it to a shop I would just go with their brands but specifiy full synthetic and/or their premium grades. The motor oil should meet GM's 4718M Corevette specificaiton. I would tell them the differential requires friction modifier unless their brand specifies that it is for limited-slip differentials (already contains friction modifier). Also the transmission in the 2005 requires fluid that meets the GM Dexron III specification.