schaack2
02-09-2005, 10:32
I'm new to the list and looking forward to learning and contributing. This past fall I purchased a 1992 K2500 with a 6.5TD and auto transmission. It is a regular cab long box and is completely stock except for a 3" lift, 33x12.50 tires, 3" mandrel bent downpipe and exhaust, new KD glow plugs, and a new Robertshaw thermostat. The truck only has 114,000 miles and is in very good condition. Here is the problem I've got... When driving the truck at a steady 65MPH on a flat road, I run about 2250 to 2300 RPM. From what I've read, I should be running at about 1900 RPM. My first thought was that the truck had been changed to a 4.10 rearend, but I've confirmed it's still a 3.42. I confirmed the speedometer has been corrected by using a GPS to check my speed. The truck shifts smoothly through all the gears and into OD, but the torque converter is NOT locking up. I know it's going into OD but the RPM's never drop that extra couple hundred. It's also obvious as I can't tap the brake to unlock the converter. I've got a co-worker who owns an OTC Genisys scanner that I'm going to hook up to it, but haven't had a chance yet. I was wondering if anyone else has had this problem or had suggestions as to where to look first? Other than this the truck runs and idles great, engine warms up properly, and has great power. If there's a form thread that already covers this topic, please let me know what to search for. Any help would be greatly appreciated as I would like to stop getting fuel mileage as if I had a 4.10 rearend (15 mpg). Thanks.