This may be a common post, but I figured, I'd throw my two cents in.

I recently purchased a Cadillac CTS-V with 18,000 miles on it. I noticed a noise at highway speeds that I couldnt quite put a finger on. I took it to Lindsay Cadillac in the DC Area and asked them to take a look.

They said the pinion bearing needed to be shimmed. I later received a call from my service rep stating that more shims were needed since the differential was still making the noise after the first repair. Another call was received a few days later stating that the car is still making the noise so they ordered pieces for an 06 differential. The new pieces came in and were installed.

My car was turned back over to me after being in the shop for 5 days. As I was driving home, I noticed a faint noise that got worse over the weekend. I had been told to take it easy and I did. 600 miles later, the differential was whining again. I took it back for again and got a brand new 06 differential put it. It has now been in my car for 5000 miles and is whining really bad. I am about to go in for a new differential again.

I did a bit of research on this topic and have noticed that in the CTS, CTS-V, Escalade, STS and Pontiac Solstice forums there are numerous complaints about rear differentials. I concentrate mostly in the CTS-V forums and know that there is a permanent link set up to discuss failed differentials.

It is obvious that Cadillac knows about this issue and has tried to play it down to avoid a huge recall and save face. You are trying to use the cheapest labor to repair the problem without giving thought to solving the source of the problem.

In the end, this will be a costly move unless you decide to void a lot of warranties. I have 25k miles left on mine, and at 1 differential every 5k, thats 5 differentials before I sell the car. I will NEVER buy another Cadillac vehicle if this is not resolved. This is unacceptable in a car worth 20k, let alone a car that costs upwards of 50k.

I have a 2005 CTS-V, owned from new. Let me start by saying, I love 90% of this car. The LSx engine is amazing, as is the T56 6 Speed transmission (I would not have bought this car if it were not for these 2 features). The sigma platform is great, I think the fittament and finish is wonderful (no rattles or squeeks at 36K miles). All this wrapped in agressive styling, fully featured at a very attractive price. I am very impressed with the CTS-V as a first effort for cadillac in the Uber-Sports market.


BUT, GM's reaction to the the remaining 10% is the issue. #1 issue, is the rear differntial. (others being the horrible rear wheel hop, (beyond that of a normal LSD), driveline backlash (way beyond 'normal' parade clunk), and very mushy shifter).

I'm on my third rear diffential carrier.

The first was the OEM. 2nd was the 'new' 2006 rear (with strengthened fins on the case). I was hopeful the second 'new and improved' part would fix the issue. It did not, and was replaced with the4 same part. I've only had the 3rd one about 1500 miles, so far, no noises.

SUGGESTION: Consider offering a cast iron version of the current differential carrier, allong with strengthened axles.

I don't drag race, burn the tires at the stop light (although this is impossible due to the wretched wheel hop), dump the clutch, or speed/power shift. I commute with my car, and really enjoy it.

Due to the '10%' issue, and GM still not having a fix for these issues:

1) My car has wretched resale value.
2) I will have a hard time justifying keeping this car once it is out of warrantee (I could do with a 5yr/100K warrantee, like the nearly identical 2007 CTS-V).
3) I will probabaly not consider a cadillac as my next car.

-Chris

Hey Trukk, have you broken your 3rd diff, or has it started whining at all? I hate to drop $1600 on a new diff (out of warranty) and have it whine like crazy.

They revised the front of the case (not sure how much) for 2008 I believe.
I haven't seen any of the new style come in whining or broken.
We have installed a few, I am pretty sure Trukk has one of the new design in his car.

At least you are close to us so we can handle it for you ;)

Hey Trukk, have you broken your 3rd diff, or has it started whining at all? I hate to drop $1600 on a new diff (out of warranty) and have it whine like crazy.

Trukk's post was from October 2006. You may want to IM him to ask him about diff issues. I don't check 2 year old threads. I'm just sayin. ;)

I think he is on his 4th now actually.