Truck doesnt wanna shift transmission is not slipping just dont wanna shift and it shakes when shifting to over drive

my guess is car has transmission issues
not stated.
please dont ask for parts that don't exist.
post full symptoms for rational answers. or tests.
no power means???????????????????
1: TRANS SLIPS, means rpm rises but not road speed.
or dont shift
2: RPM does not rise, means weak engine,.
so that is first
3: or transmission does not up shift? period or name gears not attained or skipped.

that is a hum dinger, largest ever posted, in one shot.
very good.!
one word , the transmission slips. (never drive a slipping tranny)
overheat indicator.! that is key.
many newer cars will change the transmission shifting any time
the engine over heats.
and overheat wins over transmission , every time.
if the engine burns up, what good is any transmission.? nada.

solve overheat first.

slip or flare.
is when the engine RPM rises fast and the car dont go faster.
SLIPS.
and slipping burns up trannyclutchs and increases the damage. inside the transmission, dont do that. dont allow it,
park it and fix it.

on some tranny there is a temperature sensor that the TCM
watches and changes shift patterns based on AFT fluid temps.
and if the ATF fluid gets too hot , it takes actions. to keep the tranny from harm.

why not get a scan too and see what DTC errors there are..
DTC, engine overheate.
DTC< tranny overheat (caused by above)

That is called overdrive. You have an electronically controlled transmission, so you must have the control module checked for codes with a special tool called a scanner.

sorry tosay sounds like u need a transmission

Look for vacuum leaks. There are tons of hoses, replace dried and cracked ones....

The trans shift issue that you describe seems that the trans is being told to hold back the shift, there is a unit at the end of the vacuum tube, AT the trans, called a modulator. They have a rubber diaphram inside that fails and then trans fluid gets sucked into the engine, via this vac. hose. Pull it off and see if any trans fluid comes out...Should be ZERO.

Also, your vehicle must have regular trans service, especially you must change the FILTER. Disk material eventually clogs the filter, then trans fails really fast.

You may consider having a quick lube shop do the trans service, they use a machine that pumps new fluid in while unit is running, totally flushing converter, cooler,and lines...but DO replace the filter.

To be fair, the service suggestion has nothing to do with yoru complaint, necessarily...

this problem is a common failure associated with your shift solenoinds inside your tranny. of course a shop is not gonna tell you this because by the time you wanna get it repaired it is usually too late and have already cause damage to your clutch pack and internal parts, thats the main reason why a shop wont mess with just replacing your shift solenoid (aka valve bodie)

Have you checked your transmission fluid?

sounds like you need a new overdrive

your transmission is on its way out...if it shifts only sometimes you might try to change the filter and fluid but i dont know if it will help or not

I had this exact problem on my 2005 5.3L Suburban... It would shift into 1 and 2 and reverse, but not 3 and 4.

I took it into a transmission shop, and he said the 3-4 shift solenoid was burned up. Wanted 1500 to fix it. Far from home, so I have to pay it.