4l60e no first gear?!?
 

Hi all I'm a noob here. I've Got a 2005 sierra crew with a 5.3, ls1 hot cam, zo6 springs, custom tune and a new- used 4l60e with a new trailblazer converter. The trans functions normally, downshifts,upshifts,etc.. Other than not having first at all. I can't even manually engage it. WTF? Can someone explain this to me? If it was the solenoid, id lose 4th too, but I have 4th! Cel isn't on either.

I would check that the 1-2 accum piston is not broken/cracked it can allow fliuld to bypass and apply band causing no first gear. Other gears will work fine. However ussually when this happens if you place in manual low there will be a bind up . But still work a look

Which accum piston is that? The one mounted to the valve body?

no the one with the three 10 mm bolts stand alone