The contact owns a 2005 Cadillac Cts. The contact stated that when driving at any speed, the vehicle would exhibit an abnormal clunking from the rear of the vehicle. The vehicle was taken to an authorized dealer where the contact was told that the pinion bushing for the rear axle would need to be replaced. The vehicle was not repaired. The failure mileage was 115,000 and the current mileage was 129,000. Updated 08/15/11

- Snellville, GA, USA

Defective rear differential pinion bushing resulting in a audible "clunk" when shifting gears. The automotive aftermarket offers a rear differential pinion brace to compensate for the poor GM design.

- Bowling Green, MO, USA

I have a 2005 Cadillac Cts and have taken into the Cadillac dealership for rear end loss of control and bouncing of rear end. I know there was a recall on some type of rear end issues. I am tired of arguing with the ed morse dealership in tampa, fl about the recall and defect with the car. Please advise me as to what to do.

- Tampa, FL, USA

Events leading to failure: No abuse, no tire burning. Vehicle used for commuting and job related purposes. Problems & resolutions: 7/11/2005 7/18/2005 problem shifting - dealer could not verify sunroof rattling - dealer could not verify right-rear sail panel broken - warranty repaired pixels burn on nav screen - nav unit replaced wheels scratched - dealer paid for repair front panel loose - replaced loose panel 7/25/2005 7/27/2005 left-rear panel broken - warranty repaired competition mode not working - warranty repaired dash panel loose - warranty repaired 8/22/2005 8/24/2005 wheel hop - service bulletin warranty repair hard to put in reverse - dealer says normal grinding when shifting - aligned exhaust system sunroof rattle - dealer could not verify sunroof material loose - warranty repaired 10/19/2005 10/23/2005 fuel gauge malfunction - warranty repaired 11/21/2005 11/23/2005 sunroof rattle - dealer could not verify drivetrain rough - dealer could not verify clunk when shifting - dealer could not verify car pulls to the right - tires bald @ 9000 miles battery failure - warranty repaired grinding in 5th gear - dealer could not verify 11/29/2005 12/1/2005 rattle from rear - warranty repair suspension right-rear panel broken - warranty repair; dealer warned this would not be covered under warranty anymore as "someone" is braking the panels on purpose 2/6/2006 2/8/2006 clunk from rear - dealer replaced differential/drivetrain unit under warranty. 5th gear sometimes hits reverse - could not verify grinding noise in reverse - dealer forgot to check unit won't play cds - replaced navigation/radio 2/15/2005 2/17/2006 grinding noise in reverse - dealer replaced transmission under warranty; area rep advised they will not replace future failures. Competition mode not working - warranty repaired.

- Philadelphia, PA, USA

With only about 3370 miles on a brand new car, my rear differential internals were destroyed and the housing cracked due to the following 2 reasons: 1. excessive wheel hop due to a poorly designed rear suspension 2. the differential that comes stock in every 2004-2005 Cts-V Cadillac is not rated to handle as much horsepower and torque as the car puts out. GM cut corners and put in a differential that was meant for their V6 base model Cts that makes about half the power. When the rear differential blew up, it also destroyed my driveshaft. I noticed the differential over time started to whine and clunk more and more and become louder and louder until all of a sudden while driving I heard a loud boom and a bunch of clunking and metal grinding. The car was immediately undriveable. My dealership replaced my driveshaft and the differential with a 2006 Cts-V differential which is a beefier piece. I have 2500 miles on the new differential which is already starting to whine and clunk. Wheel hop is still atrocious and it is only a matter of time before this differential breaks as well. My dealership denied knowledge of any issues with Cts-V rear ends, and tried to place the blame on me by stating that my rear tires were very worn for only 3370 miles, so I must have been abusing that car. That is not the case, and these tires are notorious for having the worst tread wear of any tire on the market, and every Cts-V owner complains about how long they last. In fact, consumers gave the tires on this car the worst rating of any tire listed on "the tire rack." See here: www.tirerack.com/tires/tires.jsp?tiremake=Goodyear&tiremodel=Eagle+F1+supercar+emt consumers rate the tire wear as a 2.6/10. What a joke, and Cadillac dealerships place the blame for the tire wear on me the owner.

- Phoenix, AZ, USA

4/11/05 - 8,367 miles - 1 day out of service rear end failure 4/28/05 - 9,664 miles - 5 days out of service rear bushing failure. Rear end failure 5/5/05 - 9,720 miles - 1 day out of service rear end failure wheel delivered from factory will not balance - no sign of damage 7/25/05 - 15,732 miles - 4 days out of service PCM recall #05544 - dealer unable to reprogram rear end hops wildly in rainy or slick roads when accelerating hard shifting into 1st gear rear end whine drive line clunk parking brake goes to floor and won't stop car rear end failure - dealer replaced rear differential and did not add friction modifier, claimed Cts-V's do not need - later determined this was incorrect 8/29/05 - 17,372 miles - 22 days out of service rear end grinding friction modifier added transmission rebuilt replaced pressure plate replaced clutch - tsb 05-07-31-001 rear end bushings installed to reduce wheel hop tsb 05-04-114-001A navigation system replaced after all buttons were peeling parking brake goes to floor and won't stop car PCM recall performed 10/6/05 - 18,990 miles- 0 day out of service navigation system not programmed properly by dealership - returned for repair 11/5/05 - 22,151 miles - 0 day out of service replace all center caps on wheels - peeling 1/2/05 - 27,171 miles - 10 days out of service rear end failure radiator failure tsb 05-06-02-005A sun visor replaced due to peeling 1/19/06 - 27,538 miles - 6 hours out of service PCM removed and replaced at gordon histed's request 1/26/06 - 28,000 miles - 2 hours out of service navigation system removed and replaced 2/2/06 - 28,500 miles - ? transmission failed again - won't shift into reverse 10 service visits in the last 9 months 44 days of out of service in the last 9 months.

- Chesapeake, VA, USA

When driving in rain / poor weather, the car during take-off violently shakes when the rear wheels spin. This shaking has thrown off my rear alignment, aided in premature tire wear, and may have caused significant rear-end damage.

- Royal Oak, MI, USA

Excessive wheel hop frequently under mild to heavy acceleration excessive tire wear, tires need to be replaced after 4000 to 6000 miles rear end differential is very weak and may break causing injury or death Cadillac knows of problem providing some customers with extended warranties had a 2004 ctsv and it was lemon lawed in July 2005 for the rear diff breaking 3 times within 1 year.

- Baltimore, MD, USA

Excessive wheel hop occurs frequently under mild to heavy acceleration. In wet conditions, it happens much more frequently and can cause serious traction and handling problems. This also puts heavy stress on the drivetrain and has caused many failures in half-shafts and differentials amongst other owners vehicles, which could lead to further catastophic loss of control. This is a major issue that is being ignored by the manufacturer at this point in time.

- Santa Clara, CA, USA