[Jason Seymour]

Hay guys my name is Jason I'm new on here but Last year I had my transmission rebuilt in my 2007 Colorado now the warranty is past I have developed a rear main seal leak and coated the underside of my truck in oil and now my transmission isn't shifting into any gears but my fluid is clean and full. WTF? Please help

 

[Jason Seymour]

Hay guys my name is Jason I'm new on here but Last year I had my transmission rebuilt in my 2007 Colorado now the warranty is past I have developed a rear main seal leak and coated the underside of my truck in oil and now my transmission isn't shifting into any gears but my fluid is clean and full. WTF? Please help
There are no error codes or check engine light on either

 

[dirtwarrior]

Could be many problems why the tranny will not shift. I wish you good luck. Welcome

 

[OldGuy]

I'd start with a "reboot". Disconnect the battery and leave it disconnected for about 30 minutes and then try again. If you've got oil all over the bottom of your truck, I'd look for electrical connections that might be filled with oil and not making good contact.
Even if it's out of warranty, I'd take it back to the transmission shop and see if they have any ideas.
Good luck, and let us know what you figure out.