Transfer Case Problem?

[yesachtron29]

About a month ago I was driving down the highway when I heard a pop and the truck would no longer move in any gear, I towed it home dropped the transmission and inspected it and everything seemed fine except a broken shifter bushing, so we replaced that remounted the transmission and tested it. It now drives but feels like its stuck in low gear even in 2wd. At 40mph in 4th gear its hitting 3-4k rpm, the only thing I can think of is something in the transfer case broke. To add, clutch seems to grab just fine, shifts between all gears fine

 

[pjtoledo]

in the front of the transfer case is a planetary gear set. that is what changes from low range to hi range.
as it changes between the 2 ranges there is a small area where it's in a neutral function. no power to front or rear.

all that happens before power is sent to the main section where the coupler for the front output is.

is the transfer case manual or electric shift?

if electric remove the shift motor and manually rotate the shaft thru it's positions.
have a rear wheel off the ground because you may have to spin it to line the gears up.

rotating that shaft does not actually shift the T case, it puts pressure on a spring that will shift when the gears line up.

BLOCK THE WHEELS,

it is possible to test it without driving. put a rear wheel up off the ground. if limited slip both wheels.
remove the spark plugs and rotate the engine exactly 1 rev, measure how far the rear wheel turns.
use 4th or 5th for better results.
the t case is straight thru in hi, a 2.4 reduction in lo.

 

[yesachtron29]

Its electric shift, I know the transfer case isnt in neutral because I can still drive the truck, it's just in much higher rpms in lower speeds, if I switch it to 4 hi or 4 lo the lights light up properly, I've removed the electric shift motor and watched it spin properly, jacked up it looks like the rear tires spin at the same speed in 4th gear in both 2wd and 4 lo

 

[yesachtron29]

Just went out and double checked again, tcase shift motor works and shift the sfhaft through the three positions

 

[pjtoledo]

time to open it up. something is broken that shifts the planetary gears from hi to lo.
the 4th picture shows the shaft and internal collars. the bottom aluminum shifts the hi/lo planetary.
the plastic moves the coupler that engages the chain that lock the front & rear together.


conversion electric to manual, what's possible, pics | The Ranger Station

 

[yesachtron29]

Thank you for the input, I'll update once I get it opened up and take a look inside