98 2500HD 2wd auto.....When not pulling anything, It shifts great going up and coming down.....Now if im pulling a trailer, (8500lbs)....It does great for the first 50 miles but then, if you come to a stop...and start out it is starting out in 3rd gear...if you shift down manually it will shift to 2nd....but I can not get it to shift to first....Now I dont have a gauge on it yet....still waiting for the mail man to get it to me....I just got the truck.<br>Now once I drop the trailer and drive just 3 or 4 minutes or so.....it will go right back to doing fine.<br>So is my problem heat related.....or is it something that I have done wrong....<br>The truck has got 56000 miles on it.....I took it to the dealer and had them change the fluid...adjust all the bands.<br>So any help would be greatly appreciated. They have no idea.<br>Thanks,<br>Allen

 

The dealer should have told you that you were in &quot;limp mode&quot; and that's why it was starting out in 3rd (or 2nd if put in 1 or 2). It's usually caused by high governor pressure. Your best bet would be to call one of the aftermarket tranny companies (DTT, ATS, etc...) and see what they say for a permanent fix. In an effort not to start a war, I won't suggest or even imply which (if any) is better. My POS trans-go shift kit had a similar problem that was repaired with a variable resistor on pin 31 at the PCM.