rear differential

I'm new here, and have an '03 w/sport pkg and 5 sp auto. At 6000 miles I had a rear axle whine at 42mph. The dealer replaced the differential. I was also told that 30% of the 6 speeds were being replaced due to vibrations. This came from the drive line mechanic at a large volume cad /gmc dealer in Phoenix. He changes 2-3 a month. Anybody have the same problems? I'm just curious. I love every other aspect of the car I'm hoping we aren't at the front end of a problematic car.

Hi,
Yes, it would seem that my wife is having a similiar problem with her CTS. She is getting vibrations at various speeds which initially led us to believe that she might have got a bad tire (just put a new set of Michelin on). She had the balance checked 4 times in 6 weeks with no positive results. The last time we had the balance checked, I personally watched. No positive result ,but I suggested that to remove rear wheels, lift the vehicle, turn traction control off, and check then. Low and behold........vibration through the steering wheel at 65-70 mph. Took it to a dealership and pretty much got the run-around.....until I lowered the boom on them. My wife and the dealership's master mechanic went for a ride.....and there the vibration was. Currently they have a new rear differential on order. Interestingly enough, I told them of the test I had suggested (removing the tires....ect) that I had the tire shop do..........they (the dealership) stated that they had not performed that check. Stands to reason that they SHOULD have done that.....rather than initially telling my wife and I that the balance was out on the tires...or it was a "maintenance" problem that did not fall under the vehicle warranty (vehicle has only 31k on it....well within warranty). Keep in mind, ALL this was told to us when we were first in the dealership....at the service desk....and none of the employees had even laid a finger on the CTS. So now, even without performing any further checks, the dealership is ordering a new differential. And tells my wife that for the 5-7 days until they receive the new diff, it's ok to drive the vehicle. I believe I HIGHLY DISAGREE with THAT statement.

Hi,
Yes, it would seem that my wife is having a similiar problem with her CTS. She is getting vibrations at various speeds which initially led us to believe that she might have got a bad tire (just put a new set of Michelin on). She had the balance checked 4 times in 6 weeks with no positive results. The last time we had the balance checked, I personally watched. No positive result ,but I suggested that to remove rear wheels, lift the vehicle, turn traction control off, and check then. Low and behold........vibration through the steering wheel at 65-70 mph. Took it to a dealership and pretty much got the run-around.....until I lowered the boom on them. My wife and the dealership's master mechanic went for a ride.....and there the vibration was. Currently they have a new rear differential on order. Interestingly enough, I told them of the test I had suggested (removing the tires....ect) that I had the tire shop do..........they (the dealership) stated that they had not performed that check. Stands to reason that they SHOULD have done that.....rather than initially telling my wife and I that the balance was out on the tires...or it was a "maintenance" problem that did not fall under the vehicle warranty (vehicle has only 31k on it....well within warranty). Keep in mind, ALL this was told to us when we were first in the dealership....at the service desk....and none of the employees had even laid a finger on the CTS. So now, even without performing any further checks, the dealership is ordering a new differential. And tells my wife that for the 5-7 days until they receive the new diff, it's ok to drive the vehicle. I believe I HIGHLY DISAGREE with THAT statement.
I have had multiple rear differencial problems with my '03 CTS. At about 15K miles, I also began to hear the whining, so I took it into the dealership & after almost 2 weeks they said they were going to replace the rear differencial. 3 days after I picked the car up, I was brought to a screaching stop at 35 mph. There was a loud bang & then I had no control of the car and was stopped in seconds leaving most of the tread of my tires on the road. They towed the car in & said the diffenencial fluid had leaked & blew the part. They replaced the part again & had someone in service department drive it & it started slipping again, so they decided to replace the entire rear axel & differencial. At this point I did not want to take the car back, but they assured me it would be okay & I was out of lemon law because I had the car over a year. Well, when I took it to have the oil changed last week, and while it was on the lift we noticed the differencial was leaking again, so it is in the shop again. It now has 25K miles and I am 100% positive that if we hadn't had the oil changed when we did, the fluid would have leaked again bringing me to another screaching stop & I live in the mountains, so they are lucky I was okay the first time. They called 2 days ago to say they didn't think the car could be fixed since it would be the 3rd time, but said they had to speak with GM first to see what the next step was & would call me back. They called today to say they have a new way of fixing the differencial by draining it and using a different sealant & leaving it to sit empty for 2 days to completely dry. I am still trying to work with the Cust. Service department to try to get a buy back. We'll see how that goes. As if this shouldn't be enough, I have also been brought to a complete stop while on the same road as before going 35 mph when my CPU told my fuel pump to shut off, this was in December so when it went into the shop, they replaced the entire computer chip. Oh, I also forgot the fact that they are also replacing the transmission while it's in the shop this week b/c it's leaking & making noises. These are really just the major problems not including the front seat always breaking, license plate area leaking, and the list goes on. I love the vehicles looks, but no longer feel safe in the car. If you have signs of the diffencial having any problems, I urge you not to drive the car b/c the results of it breaking could be devistating. I am beginning to think that is what it is going to take for GM to buy the car back.

Sandaferrin,
I see your problem. I would try QuikMechanic at:
http://www.ineed1.com/quikmechanic.html

I used them before, and they helped alot. It's alot cheaper than going to the shop and they don't fix it, but charge me $68 or more per hour. It's just $1 anyway, so you can't go wrong.

Chutch

There have been numerous instances of problems with the rear differantial on the CTS. I thought that they were limited to early production 03 models (produced in early 2002) but I saw service histories on some 05 that also had the rear differential replaced, so I guess that STILL haven't got this solved completely. I'll be watching my wife's car closely.

They also had a tire recall on all 2003s, but it expired in Oct 2004. If you bought tires for an 03 before oct 31 2004, I would try to get the cost refunded.