One problem related to automatic transmission torque converter has been reported for the 2005 GMC Yukon. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 GMC Yukon based on all problems reported for the 2005 Yukon.
I have had problems with my 2005 denali shifting. I go to stop and then take off and it acts like its slipping and then all of sudden it grabs with a clunk. This has happen at all times of it being driven. I have taken it in to the dealer put unless they can duplicate it then they cant fix it. Well gm will not pay them for warranty work unless. Now it has gotten to the point that it made a loud clunk and then was slipping as you pushed the gas, so right then we took it to the dealer so they could drive it. The transmission tech drove it and look at the trans fluid and it was 1 1/2 qts low. No leaks ever and it has been in to the dealer at least 5 times and 3 in the last 2 1/2 months and the fluids, I hope were good. Tech topped it off and it shifted fine for the weekend. Then the next Monday it started slipping and hardly accelerating again. Took it back in and the tech checked code and it had some torque converter codes. They replaced a wiring harness in the transmission. I work for a couple of days then it started again. We took it back in and the service dept. Called gm and they had them change the ignition sw (module I think). I will post code and exact when I get the info from the dealer. I will see if this fixes it.