I have a '96 Yukon with a 4L60E with 240,000 miles. I am not the original owner so I don't know if the transmission is original or rebuilt. I have owned it for 75,000 miles so the transmission has at least that many. I do regular filter and fluid changes every 30,000 miles.
Recently it has been exhibiting, under certain conditions, a shudder when the torque converter is unlocking. This usually occurs when going uphill at around 70mph (approximately 2000 rpm). If I am going uphill with the converter locked and give it a slight amount of additional throttle, the rpm's will rise slightly (not as much as a full unlock) and there will be a pronounced shudder for a second. As soon as it unlocks, everything is OK.
Any suggestions as to the problem?
Thanks in advance for the help. Rich