Chevrolet Forum - Chevy Enthusiasts Forums - 1988 Chevy k2500 transmission won't shift...sometimes

So, update time. I got my truck up to my father in laws, who, I will say, is a MOPAR man through and through and I know it was killing him having a huge Chevy in his driveway (because he kept telling me it was killing him) next to his Roadrunner, but we did the following:

1. Put the tailgate back on - this was a pain, but worth the work, dang rust.

2. Replaced the inline fuel filter - was pretty straightforward, and he mentioned the underside was strangely well ordered and clean "for a POS damn GM", whatever.

3. Swapped out the transmission pan gasket and filter - when I took the pan down, the filter fell off into the pan. There was also a little over a half inch of metal shavings on the magnet, so it had maybe been a while since this had been done? The fluid didn't look very good either, so I'm thinking a full flush is in order as soon as I can figure out how much Tranny fluid I need. We got it all back together and he wanted to test drive it (surprise surprise) and noted that while it WAS shifting a lot better, it seemed like the torque converter was going out. The truck would kind of whine when you tried to gun it, and it would do a really sloppy feeling shift trying to slam into 2nd. Anyway he said to think about the torque converter, but I drove it home (about 16 miles) and it felt great to me, but that may be because I'm used to driving it.

All in all, the things I have tried on it have been cheap and simple fixes, getting under the truck without needing a jack was very nice too :P

I am going to see what pans out with the gearing, he (my father in law) worked for the city and drove a 1986 Suburban and said the shifting problem was not that bad, these old Chevys shift a little high when they are cold, but he was able to take off and get it going without waiting 15 minutes to move like I used to, so there's that.

A huge thank you to everyone who helped and responded, I also bought a Chilton and now know enough to know that if the torque converter is out, that may mean a trip to a shop as it's NOT something I should try doing :P

Could that also be why the 4X4 isn't working?