I can see no possible way TC can lockup after 1st gear. And I am looking at the fluid flow diagrams.

 

That would make our trannies 7 speed.

 

Going back to my original question. I have two trucks that are identical body styles, see sig. I am using the 99 for work and it's usually got over 1000 lbs of extra weight on it and unless it's very windy I've never had to play with the OD button. It will shift into OD at 42 to 45mph. The 01 with smaller 5.2 has to hit 50 before OD kicks in, and was wondering if that's how all the 5.2 are programmed or is does it have more to do with year of truck? Take in mind where I live is flat as a pancake!

 

My 2000, 360 with 410 gears and my 98 , 318 with 355 gears both shifted into OD at 45. Same body style and same tools in both. They both also have/had 265 tires. And both had the same superchips tuner. Only when I went with the SCT tuner on the 2000, did the shift to OD change to 50. So I certainly can't explain your difference in the two trucks. Other than the fact that one is working harder than the other to get up to speed.

 

And THAT would be interesting!



I agree. without knowing everything, including how PCM is programmed, there is not much way to know how or why. Fact that they shift differently and one works harder to get to speed......enough to know that if it is yours, you can correcnt the issue.

 

The newer trucks are not that far away from being a 7 speed transmission. Some of the Ram trucks aready have a 68RFE transmission and the jeeps have a 65RFE transmission. The chrsyler 300 has a ZF 8 speed trans and then next model year, you may see a 9 speed transmission. gdstock is correct. The pcm controls the overdrive shift. But it also gets the input from all the other sensors to control tcc lock up.

 

I was reading in the Snap On manual that I have with my MTG 2500 Scanner as I was putting it up after checking out krenard's Ram yesterday. It has some interesting diagnostic info in there, including some ot the PCM logic that is not appearent in the Ram manual. Ther appears to be a lot of other sensor data that comes into play. Although I cannot quite understand it all, it must make a difference, as the sensor data and logic appears pretty complex.

 

What I thought was a new flash sticker on the the PCM, is actually a sticker indicating a new Mopar PCM was installed on my 01 by PO last year. Guess I'm resigned to the fact that the 5.2 has no power after hitting 50 in OD. It has to downshift to 3rd to get up to 65 or 70, or if driving in OD in the 50 to 70 range and encountering a slight wind or incline, it will lose speed and downshift easily. Disappointing after driving a 5.9 for so long.

 

What size tires?

 

245/75/16 on my 01. 225/75/16 on my 99. Everything is stock on both. Just had the 01 into have trans serviced and is clean as a whistle in there.
Would different gears be an option to increase low end torque? And would that change gas mileage which isn't any different from my 5.9? Or should I sell and start over? Hard to find these barely used 2nd gen's tho.