GMC Savana Transmission wont fully shift

[versa7623]

I have a 2004 GMC Savana 2500. This morning I noticed when driving it, it would shift really lightly into the next gear, like you would almost not even notice, different then normal though. After I parked for a bit I started the van back up and put into Reverse and nothing, so I tried Drive, and everything else nothing unless I rev it up I can see it move about an inch or two. Any Ideas, I just want to rule out everything before I take it in. Checked the trans oil OK and also that Park Neutral Position Switch on the side and the cable moves the arm on it. I drive this van everyday for work and if the transmission was going out wouldnt I notice any slippage or anything before, it was running great yesterday? Any help would be appreciated. Thanks

[gmtech4]

if its done the oil sould be dark and stink ,

 

check engine light on ??

 

all i got ,,,those 4l80s suck,i rebuilt a zillion of them ,,,,a few in my sleep lol

[versa7623]

The oil seemed fine, and no check engine light. One other thing I did just find out was my trans dip was at the same level on and idling for a minute as it was off. Would that be the pump in the transmission? Called around everywhere I found was at least $2500 for a rebuilt one. Someone please tell me its not my transmission lol

[gmtech4]

the oil pump pulls oil from the sump and supplies oil to transmission,there by lowering the level,

 

 

if its the same off and on,you answered your own question,i will not say another word lol