Car studdering on 2004 Buick Rainier

My 2004 AWD Buick Rainier at 25 MPH makes a thud sound and then between 30 -35 MPH the car seems to studder. Does anyone know what can cause this?

by in Alamo, TX on July 17, 2009
4 answers 4 comments
ANSWER by on July 17, 2009
It could be your Torque Converter clutch. Do you ever have a check engine light or service engine soon on? let me know. Good Luck!
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COMMENT by on August 16, 2010
I'm actually have the exact same problem as brittanyc, and my truck is currently at the dealership as we speak. I'm concerned it might be the transmission. :(
COMMENT by on August 25, 2010
My 2005 seems to be doing the same thing. New tires all the way around. The engine runs smoothly. It even does the thudding when in neutral. This happens when accelerating or slowing down. The check engine light will light periodically, and then goes out on its own.
COMMENT by on December 31, 2010
Our 2004 has done this for the past three years. The dealer replaced the transfer case on warranty and the issue wasn't resolved.. GM told us it was a design flaw caused by the torque of the AWD system changing when accelerating or slowing down. We discovered that this problem can be somewhat mitigated by making sure that the transfer case fluid is blue and not some other color. Ours was green. Also, mismatched tires or tires with different tread depths can cause the problem to be worse. Good luck, but this is a design issue. We've decided after five Buicks, that this is our last GM product. I've never had these types of problems with my Nissans or Toyotas.
ANSWER by on June 13, 2010
my buik rainier 20o4 mph makes sound and like die to much gas
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COMMENT by on July 14, 2010
check the tire pressure. They front tires should be around 30 and the back around 35. Check the panel on the drivers door for the specs. It has to do with the electronic stabilization. We had new tires put on and they set them to the tire specs instead of the GM specs and had this problem
ANSWER by on July 20, 2010
Ihave04& imhavnthefrontdifferentialrefilled withadifferentfluid mech. Tellsme to keep working it.
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ANSWER by on January 31, 2011
It's the water pump. I had to replace it twice already this year.