front tires don't spin in 4wd

front diff actuator functions good
but my front tires in 4wd have no power any ideas

 

Does the front driveshaft spin when in 4wd? That will tell you if the transfer case is working.

 

just put a new used transfer case on it and it spins driveshaft

 

Then somehow the front actuator isn’t doing its job if it’s functioning. Could be something internal to the differential itself.

Out of my zone of expertise.

 

Sounds like your front actuator...

https://www.tundras.com/threads/1st-gen-4wd-issues-diagnosis-prevention-guide.149189/

 

Have you jacked the truck up and verified neither wheels are spinning when the truck is in 4WD? If you're stuck in 4WD, the differential will only send power to one wheel because it is an open differential. This is what people refer to as one wheel peel. Since the front differential is open, the front wheels spin independently. The wheel with the least amount of resistance/ traction will spin while the other is freewheeling.

You will have to disconnect the rear driveshaft from the transfer case if you jack the front of the truck up to test whether your front wheels turn in 4WD.