2000 Tahoe Z71 (OBS) Newish 4l60e will not go into gear after sitting for 6 months or longer.

[FreshBoxLive]

Rebuilt 4L60e with around 5000 miles had been working perfectly fine for a year or so (it's my third vehicle) before sitting for six months. Today I charged the battery, dealt with PASS lock and fired it up. I let it idle for kind of a while. Like over an hour while I cleaned the interior. Cleaning took longer than i thought because i found rat turds and stuff. Anyway, when everything was cleaned up I went to put it in reverse and nothing happened, jut rolled back like it was in neutral. No gears at all I tried individually selecting each one and no engagement (I did notice a change in engine RPMs.) Weirdest thing was when I put it back in park I heard a strange grinding sound that reminded me of the sound of pulling the parking break on a Honda car. Now the truck rolls when in park so I may have somehow done damage to something when changing gears in that state because it was fine before. Some things to note about this truck; It has spent the last two years almost living on the Oregon coast, it had a thief cut the wiring harness and take my whole K&N air intake system. It being not a daily driver I have not replaced the wiring harness or air intake. Currently it just has a cone filter for an intake and thats it. So there is no MAF (live rurally so I don't have to smog) and I have heard that can mess with the transmission. I have put around 7000 miles on the truck driving with this configuration.
Incident occurred later in the day so only have checked fuses so far. I'm gonna check fluid at cold temps tomorrow.
What do you guys think could have happened in the months it was sitting? Is it possible rats did some damage to something somehow? Did something rust? Did I leave it idling too long and damaged something? It just seems bizarre.

 

[B-train]

I'd say corrosion of the affected wire harness you mentioned. Or rats munching on wiring. Sounds like quite a project.

By chance, did you check the fluid level? I'd start there. If it's low, looks for leaks. If no residue, then check the transfer case and see if it's way overfilled. A bad seal can allow trans fluid to push into the transfer case.

 

[bsamole]

The transfer case could be stuck in Neutral.

 

[Eman85]

Your transfer case isn't in gear

 

[FreshBoxLive]

Thank you guys for the responses. I will check fluid today after work and see if the transfer case has atf overflowing the fill hole. As far as the transfer case goes, any idea what went wrong or what to look for? I'm still thinking it's gotta be from lack of wiring.

 

[FreshBoxLive]

Fluid levels are good, and is clean. Any suggestions? Right now the only solution I can think of is replacing the whole wiring harness and transfer case.

 

[Fless]

What wiring harness was cut? Where on the body?

 

[FreshBoxLive]

What wiring harness was cut? Where on the body?

Here is the configuration I had been driving with with zero issues for about 7000 miles until it sat for six months. I should of posted pictures originally, my fault.