Hi all,

Our 2007 GS AWD has had a bit of a shudder since we bought it 6 years ago, but it's getting slightly worse now. It happens randomly, and I cannot link it to anything like braking or the way I'm driving. Seems to occur a bit more often when or just after turning, and when the car is cold. Could anyone point me to some obvious things to check? I can't pinpoint the shudder to any particular end or side of the car. It's about 10 Hz if that helps,a nd the shudder lasts for a few seconds each time.

Thanks for any tips!

 

So you take a turn are you on the gas or on the brakes when the shaking, does it change if you turned left or right? Have you checked the obvious like the front wheels made sure they are not bent and are properly balanced?

 

Happens after a turn, but also just in a straight line sometimes. It's not a wheel balance problem - I alternate between two sets of wheels (ice and regular tires) with no difference. The shudder is always at lower speeds, up to about 25 mph.

 

Does it happen in the front or the back of the car? When it shudders does the rpms drop or raise or stay the same?

 

Can't tell front or back, seems whole car. No change in RPMs.

 

When the shudder happens does the yellow tire slip symbol flash?

I wonder if its your front differential, because that can make noise when you turn the when as one side of the wheel speed will change in turns. Have you ever chained the fluid. Have you taken it to a mechanic to have him test drive it?

 

No lights come on. Front diff sounds plausible, but those things are solid, though I never changed the oil in it.

I'll put it up on the lift this week and see if I can get it to vibrate. Is there any issue with letting it idle in drive up on a lift with all 4 wheels free? On my LS I think I had to turn off the traction control to calm it down.

 

They are solid, but if a seal goes out and fluid drops to low. It will give you issues! Wont hurt to replace the fluid on the front and rear diffs, and inspect the fluid as it comes out. If your diffs draining a bunch of metal shavings thats a good sign.

Not sure if letting all four wheel spin will give you any issues, I doubt it as its an awd and all 4 wheels should spin so the speed sensors should register.

 

My GS2007 is doing the same thing about a year ago. Randomly, at low speed below 25 mph and accelerating, or slowing down to make the turn then accelerate straight forward.
I had the front fluid differential replaced at 90K miles. The car now has 155K miles.

 

So the issue was low on fluid on the front diff?

 

I don't think it's low differential fluid. The issue happens from time to time when the car accelerates from stop to 25 mph.
Not sure if leaking inner CV boots left & right front have anything to do with the issue. The leak has stopped on both sides.

 

Chuck - do you mean you replace the fluid or the diff?

 

Im having a (similar) issue. Though mine feels like its the whole car. Almost like its directly under me. I have an 08 AWD.. Last wknd i changed my transmission fluid, while under there, i saw this mount in the picture.. it looks worn. It is not the transmission mount. The part number says its a (dynamic damper.) From what it appears. It looks like its located under the transmission mount... so im going to try and order one. I need to get a trans mount also... hopefully i can change them and it makes a difference

I guess i could have taken a better pic. But at the time i took it. I was only concerned with the part number. I'll try when its warmer to take a better picture. As its 22 outside..

 

But where does it look worn out? Did you start the car and notice it wiggle, or vibrate

 

No, i didnt start the car. I noticed it while changing trans fluid.. that bolt that u see, has a large gap from were the rubber is. It doesnt look like it from the pic. But looking at it side ways, you can see it.. And i was able to move it with my hand... I don't have another picture of it. Like I was saying in the post above, I was only concerned about the part number when I took that picture.