I just got done replacing the sun shell in my 98 Tahoe 4L60E. I didn't do an overhaul or rebuild. When I got into the tranny, everything friction to steels to neoprene looked great. No metal inside was burnt, nor was any of it showing any signs of wear. It looked as if the tranny has pretty recently been rebuilt. Putting everything back in was a breeze and install was a breeze. I made sure the torque converter was on correctly when I reinstalled it. Before tearing into it I obviously didn't have 2nd Of or reverse due to the sun shell. When installed i filled the tranny with the initial 5 quarts of fluid and one in the torque converter. Started the truck and added six more quarts. Let it run then checked it and it was right on the full crosshatch. I switched the truck into reverse and WOO HOO! The truck moved off the ramps. When it got level on the ground I began switching through PRND a few times back and forth. In the midst of doing that I noticed the truck wasn't trying to move forward. So I switch through all stages of gears. All that worked was park reverse and neutral. No OD, no 3 2 or L. As soon as I switched to 3, then service 4wd light came on. I hopped under the rig to see if I has missed any connections but they were all plugged in. I then pulled the PRNDL fuse out of the fuse block under the dash. Now OD AND 3, the truck would move very slowly no matter the rpm. The service 4wd light turned off. I replaced the fuse and tried again. Light came back on and no movement in any forward gear. I then noticed my p.o.* push button 4wd lights werent on. Couldn't tell if I was in 2, 4L, 4HI, or auto 4wd. Pulled the PRNDL fuse again, replaced it and the button lights came on. I pushed 4L and it switched into 4HI but wouldnt switch out of 4HI. I turned the truck off, pulled the negative terminal on the battery for a few minutes plugged it back in. Still nothing different. Service 4WD light wasn't on until I switched into 3rd gear. Still the truck won't move. I'm at a loss right now and don't have a clue as to where I should start looking. Any help would be highly appreciated. I would also like to add that I don't have an obd ll tester and I live 45 minutes from town. I also am on a very limited budget since I can't get to town for work, (I also lost my job due to the situation.)

http://gmsi.gc.maricopa.edu:9001/si/...537454&from=sm

im no trans expert but if reverse works the tcase must be fine. so i would look at the electrical inputs for the trans and if they are there, then something is wrong in the trans. there is a list of shift solenoid pins in there you can test them with a meter to see if something is open in the trans as well

So it would be best to start in the valve body and work my way from there? I would hope to not have to pull the damned thing again. Since not having forward getting on the ramps will be a fun one.

just know about electronics unfortunately. im in the middle of my first time doing anything inside and i messed it up and have to take it all back apart

Uh oh. Yeah these things get more and more tedious. I hope the guy that decided to make trannys electronic dies a slow death. (Kidding) I've rebuilt 350'*, 400'*, muncies, saganaws, and never had an issue with them after. I was told the 4L60E was an easy tranny to rebuild. I strongly disagree.

Last summer I dropped my trans for the same issue. Only thing I replaced was the sun shell itself. Everything else was put back in ok except for that one little *^$*^(*^(^#&#(^# snap ring that was a joy to remove.

Only thing I can think of is to re check all connections.

The one holding the tail shaft and sunshell? That thing took me about an hour to get back in.
I'm really hoping its just an electronic deal. All I've got is basic tools and the special hook and picks, and the snap ring pliers that don't really do much justice. Dropping that thing is no fun for a guy in my position.

No it is not, I practically busted my hand trying to stop the transfer case from making a dent in my driveway.

Well.... I think I might have it figured out. After thinking long and hard, I had my parts 700r4 in the shop with me. When I put the 4l60e back together I remembered seeing one of the input shaft seals had a cut in it. I thought it was one on the 700. Well after all this trial of wondering what was going on, I grabbed the input shaft from my parts tranny low and behold the seals are perfect. So now I will be dropping the one out of the truck and replacing just the one stinking seal. Yay for me!

Update-ish. After lots of procrastination. I took her back out and took the pump off. The seal rings on the input shaft were actually good. (Must've had a dream that one was broken). But I did notice that the parking paul was not in the little pit deal so to speak on the 2-4 band. Would that cause me not to move forward? Everything else I've looked at checks out.