So my K5 has been being doing this thing where when I start to go down hill its down shifts and my RPM's shoot up to about 3500. The only way to get it to stop it step on the gas and it will kick up into OD but once I let off it shifts back down, It will do the same thing on almost flat surfaces even when I have the cruise set. My tranny is a NEW 700R4 mated to a NEW NP241 t-case, motor is still stock. Any ideas or clues.

Respectfully

4 inch lift
3/4 axles
4.10 gearing
1 ton drive shafts
33's BFG's Mud Terrains

 

your TV cable could be out of adjustment - might try readjusting it

 

Thanks I'll giver a look.

 

Well I checked the TV cable and it seems good, still have same issue, but I did notice it does it only once the tranny has warmed up.

 

Sure sounds like a misadjusted downshift cable.
Who installed the tranny? The same person that rebuilt it? Can you take it back to that person?
In the meantime... try shifting the tranny manually to see how it acts... and/or throw it in neutral when going down hill but I would be very cautious about doing that.

 

I did take it back to the place that rebuilt it a few different time and he said gave me the same anwer "that it was normal and supposed to do that for that year". So now I have no idea what to do until I get more money to take to someone else. Thanks for your help.