check this out, my husband was driving our 79 k5 blazer (4x4) to my fathers house. we stopped at a gas station to get us drinks. when we were coming back onto the highway, we had to kick in the 4bbls, the tranny downshifted to 2nd gear, and never shifted back to 3rd.
we took the filter pan off, the fluid was hershey chocolate brown, and very very minor metal shavings. the filter was shot, soaked black all the way through, so we do not know when it was last changed. we put new fluid in and a filter, started her up, put the foot on the brake, brought her to a high idle and shifted through the gears to get fluid in the pistons. Took her for a drive, still no 3rd. any input? we think maybe the kickdown cable is broken somewhere in the mix. there was no problems with the trans before this incident. we dont know the first thing about trannys, so we need all the help we can get! Thanks guys.