Hi, I bought a 2003 GMC Yukon Denali a few months ago for the engine to swap into my classic truck, but was hoping to drive it for about a year while I finish the work on the truck. It has the 4l65e transmission that had no 3rd or 4th gear. I bought and installed rebuild kit that replaced all of the steels and clutches, bushings, bearings, shift solenoids, Corvette servo, etc. Once put back together I drove it for a few days and it seemed to run fine through 1-2 and 2-3, but 3-4 was sloppy. It eventually threw a P1870 code. I installed a Transgo shift kit that was supposed to fix that along with a new wire harness and tcc solenoid. Now everything shifts worse. 1-2 is ok but 2-3 and 3-4 slips and revs when driving more aggressively. I was thinking that it could be because of a worn separator plate, but I don't want to throw more parts at it if it won't fix it.

 

Which Transgo shift kit did you use? Did you enlarge any on the holes in the separator plate. What did you set the 3-4 clutch clearance at? How much travel does the 2-4 servo have?

 

It was the Transgo orange box. It had me enlarge several of the holes per the instructions. The other questions I'm not sure how to answer. When I replaced the clutches and steels, I used all the ones that were in the kit and reused any of the wavy steels and backing plates so that it would be the same as what came out. I'm not sure how to check the 2-4 servo travel, but the original was replaced with the Corvette servo. Do I just push on it from the outside? How much travel am I looking for?

 

.125 or less