: What are the signs of a worn Carrier in AWD STS?



Powell1D
08-07-10, 05:27 AM
I am new to posting and came across this problem so I am asking for some "HELP!" I got a very good deal on a 2006 STS 4. I recently took it on the road to FL from NY and started getting this clackitty noise form underneath the car around the center. Mostly form the front of the car, but sometimes from the rear (especially from rear on turns) After the noise the car catches and is smooth as silk. It returns when I try to pull off from a full stop and sometimes when I'm cornering. Always after the noise, smooth as silk. Growing up being called "Mr Goodwrench" I am somewhat of a do it your self type. There is no clanking when the car is still. Even when I shift form D, N to R and R, N to D. The torque it takes to move forward 'quickly' and I discovered up hill, produces it. Sounds like a gear trying to catch. Anybody have any idea what I need to have adjusted or replaced. I returned from FL like this, practicing slow take offs and hope that it"s not anything major.

next2pool
08-09-10, 04:23 PM
Is this ocurring while accelerating only? If so, this sounds like the traction control activating--when it does this next time look at the driver info center in the instrument cluster and see if it says "traction active"

turnne
08-09-10, 09:28 PM
Sounds like the infamous STS AWD "chuggle"
If it only happen on acceleration and more often than not between gears 2-3...you have a very common problem for the vehicle



Warren

stevenriz
08-10-10, 02:35 PM
I am banking on your traction control activating as mine does the same thing on some right hand turns. I don't know the resolution because I never had it looked at. next2pool or some others may know what needs looking at. Sensor or otherwise...

dkozloski
08-10-10, 03:27 PM
The car has staggered tire sizes. The tires are smaller and the wheels narrower in the front than the rear. Make sure that someone hasn't swapped them around in a misguided attempt to rotate tires. This could activate the ABS and/or stability system. The correct tire information is available on a driver's door sticker.

EChas3
08-10-10, 10:20 PM
There are several variations. 18" wheels are identical all around but carry staggered rubber. The 17" staggered setup has wider wheels on the back along with staggered rubber. Compare your tire info plate (driver's door jam) with your installed tires. Some members have reported issues when different than OEM.

IMHO, there's something wrong if you get frequent DIC displays. I didn't any when mine were stupidly rotated to opposite positions.

Powell1D
08-13-10, 10:09 PM
Wow....Thanks for all the reply's. I just hope I didn't put the cart before the horse by taking it to my local garage before reading the post's here. The guy there told me the transfer case was the problem. I wasn't too sure about the diagnosis because I also heard the sound in the rear sometimes as if it was coming from the shaft that connects to both carriers. I thought both going bad was highly unlikely. The first time the noise began though was after running on the spare, replacing the right rear, for almost 300 miles. Why? That's another story. However, that's when the noise began. I purchased a pair of Nexen tires in Florida. A really good buy. Being that I am used to FWD I had the newer tires placed in the front. They are noticeably healthier than the rears. If the stability control is that sensitive it gave no DIC indication. I've only had the car for three months and that traction light has been on for a while though.The funny thing about it is it went out today on the way to take it to be diagnosed. I wont tell the garage about the stability or traction posts. The transmission runs smoothly on very slow take offs from stops. When the torque is quickly required to move the weight of the car is when it occurs. Once the car is rolling, no problem. I drove it over a thousand miles hitting speeds in excess of 85mph. It's good once the car is rolling. In order to get the noise while the car was in the air, without the weight of the car, they had to really rev up the engine speed to get a sound from the transfer case. The sound is not one that should come from any car, let alone an STS. Will post a follow-up.

next2pool
08-14-10, 12:46 AM
Yup--if you have the staggered tires on the wrong end, you won't get any indication from the TPMS, traction control nor stability control. The diameters are close enough to not cause any problems. Off hand I can't think of anything in the diff itself that would cause this. Possibly a U-joint could.

EChas3
08-14-10, 01:07 AM
The spare really works the differential(s). If you exceeded rated speeds on top of running it 5 times the recommended distance, you were asking for trouble.

fps_dean
08-15-10, 12:48 PM
There are several variations. 18" wheels are identical all around but carry staggered rubber. The 17" staggered setup has wider wheels on the back along with staggered rubber. Compare your tire info plate (driver's door jam) with your installed tires. Some members have reported issues when different than OEM.

IMHO, there's something wrong if you get frequent DIC displays. I didn't any when mine were stupidly rotated to opposite positions.

The 17s have wider wheels on the back? Mine were all the same, and several others said the same thing but when I got my car I had the original Michelin Pilot tires in staggered sizes still on it...

EChas3
08-15-10, 05:13 PM
If your car was OEM on staggered 17" tires, many knowlegible members have posted that your back wheels should be 1/2" wider. It's stamped on the wheel somewhere. I doubt it would cause an issue.

Maybe two or more of the wheels were changed?

next2pool
08-17-10, 04:04 PM
Do you have the limited slip rear end?

dkozloski
08-18-10, 02:01 PM
I install the same size Blizzaks all the way around on my '06 STS for winter driving. When they are on the car a blind man could tell that the rear wheels are wider by the way the tires fit the wheels. That being said; they work just fine.