The reason I am posting this is several years ago my 84 s10 utility body truck did this exact thing and I took it to a transmission shop and they told me they replaced some small plastic gear, charged me $75 and it fixed the problem. Would anyone on this forum know what gear this is that would effect the shifting and where it is located? The transmission shop only had it a few hours and did not remove the transmission to get to it, evidently for that price. I thought I would fix it myself this time or at least see if it is the same problem. I had the transmission rebuilt probably 50 k miles ago for $1000 and was hoping I could fix it cheap not wanting to spend much since it is a 84 and subject to have other problems. Any help would be greatly appreciated.