I own a 1982 gmc 1/2 ton pick up. The transision will not shift out of low gear. When you hit around 15 or 20mph and shout off the gas it is like it goes in to nuturl. Years ago when this hapend I changed the "vacum modulator" and I would be off again. I looked EVERY WARE on the transision and there isn't one. HELP! I check the cables to the carb and all looks OK. I had a 87 ford that did something like this and it was a rod going from the carb to the trans that fell off but this truck don't have one. Can you help? PLEASE! THANKS CHARLIE

To me it sounds like the trans it getting ready to go or it is in desperate need of a filter and lube change. :( I've used this stuff from napa auto parts. Its made by lucas and it goes in the trans like normal trans fluid when you change the fluid and believe me it totally made it run like new. But if it hasn't been changed in a while it needs changing. And it could be its low as well. The way you check if its low is have the truck in neutral and leave it idle for a while till it warms up fully. Then check it. If its not either a nice green color or its not a nice red color then its in need of changing. Green is the color of mercon dextron fluid. Red is the color of original gm fluid.