In my 91' lumina I believe I have the 4860 trans in my car unless I read the numbers wrong that are on the bottom of the transmission pan. I had a friend that tried to find some info on it, and he found out that they only put 2 different transmissions in that car one with an E at the end of the number and one without (I have the one without the 'E'). He also told me that he read that those transmissions were some of the worst that chevy ever made (but you can hear that about anything). The gear selector reads as follows P R N OD D 2 1, the problem i have is that when i put my car into OD and the car actually shifts into overdrive that when I come to a stop my car is 'out of gear' and I so far have been able to put it in 1 the car will go back into gear and then i can drive in any of the other gears. What my friend found out was that I did not seem to be the only one with this problem, he said that most of the people just had to clean up and tighten the ground wires on the transmission back up... problem solved. but when i tried to find this info so i could fix this problem, I could not find anything (neither haynes or chiltons manuels offered any help). So now i ask the people... can you help me PLEASE?