Truck is a 2007 New Body 5.3 4l60e with 169k 4x4 z71 towing package G80 rear end, Stock everything except have has a diablo intune on for 5 years with the 87 octane tune, shift firm, and AFM/DOD turned off.
i believe the shift solenoid has gone out but what a second opinion. (never changed the fluid in transmission either) (yes i know dumb but here i am)
Was driving yesterday and was driving hard and the shift from 1-2 the engine bounce off the rev limiter 3 times till i realized it was not shifting then it grabbed second and was fine.
Come to a stop when i reach town and take off and in 1st gear it revs to 2500-3000 rpms before it finally shifted to 2nd. all other shifts are smooth 2-3 3-4 and even down shifting from 4-3 3-2 when "passing". also down shifted to 1st no problem when coming to a stop at a light. same thing today with over reving in 1st gear before shifting. I can help it along if i get to 2k rpms and let off the gas and feel it shift then get back on the gas it is fine but if i stay on the pedal even at light throttle it goes to 3k
No check engine light no other codes of any kind.
So hoping shift solenoid and not a grenaded 4l60e, i have read many post but a lot of them mention that they had a check engine light for the shift solenoid and i dont have that so that is why i am here.
Thoughts?