Quote Originally Posted by mjgrantham2003 View Post
Hello, I am new here and in search of advice regarding my 4T65E trans. I actually drive a Montana, but I find little help on other forums, and this one seems to have a lot of knowledge and activity regarding this trans. However I can't find an answer to my problem/question in existing threads. I want to know if the improvement in line pressure you would get from adding a shift kit would secondarily cause a more positive engagement/transfer of power at the torque converter due to increase in "line pressure". Mine just hit 250k miles and since I've owned it has always seemed to have a laggy/weak torque transfer. Not sure I'm explaining this right...the RPMs required to get the thing up and moving is higher than other vehicles I've owned, including my previous vehicle which was a Venture that had same motor and the 4T60E, which was super quick even @ nearly 200k miles. Along with the laggy, higher-than-normal RPMs on acceleration, the shifts occur at much higher RPMs than they should, and they are the slow, delayed shifts which sometimes then become hard. I am fully aware of the 1811 code and related issues. So would it be worth trying a shift kit? Could it help? I'd appreciate some expert insight. Thanks!
I know exactly what you're talking about. I went from a '98 Montana Transport (4t60e) to an '04 Silhouette (4t65e). The shift characteristics are so different, I thought something was wrong with the new van. Like you said, higher RPM shift, long shift time.... If you look at the actual tune, the shift times for the more modern vans are super long (over 0.4 seconds) compared to a much quicker 0.2 seconds or so of the older vans. Having said that, I did put a shift kit in the new van, and it helped a little but nothing major. I think it's just the way they are programmed/tuned. To give a softer, more gentle acceleration feel.