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

2K views 12 replies 7 participants last post by  dkozloski 
#1 ·
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.
 
#5 ·
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.
 
#6 ·
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.
 
#7 ·
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.
 
#8 ·
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.
 
#13 ·
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.
 
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