I have a 94 S-10 V-6 Z code engine 2WD truck with 148,000 miles. I removed the transmission pan to change the fluid and filter and also install a Transgo SK4L60E shift kit. Now I have no reverse and also it slips between 2-3 gears. Note: the transmission worked fine before I did this job so I am sure I've done something wrong. I checked the fluid level after an 18 mile drive and it's OK. I also installed an updated manifold pressure switch on the valve body which is a fully enclosed unit unlike the original one. I need some ideas one where to look for my mistake. I did this same job on my old 98 Bravada with no problems at all and have no idea what I did wrong on this one.
I tried to call Transgo and ask them about the problem but the phone just rings off the wall with no answer. I wonder if they are still in business.
Thanks in advance.

Anyone have any ideas on this problem? Since it shifted fine before I worked on it I have thought about dropping the pan and putting everyone back stock. There are no trouble codes by the way.

Anyone have any ideas on this problem? Since it shifted fine before I worked on it I have thought about dropping the pan and putting everyone back stock. There are no trouble codes by the way.

Good idea.
Most shift kits work better in the trash can.

I would get a good rebuilt valve body for it.
Good Luck