Rear not engaugeing and front slipping

[Lchapman]

Truck was running perfect today then rear wheels stopped and then front wheels just started slipping. Engine runs great. If I hold truck still engine runs but no wheel operation. Pulled transmission apart no broken or grinded gears. Not sure where to look next.

 

[ELWOOD]

@Lchapman

TYPICALLY ONE OF THESE GRUB SCREWS FALLS OUT
FROM THE OUTPUT CUP OF TRANSMITION (FRONT OR REAR ) OR FROM
THE INPUT CUP OF THE DIFFS ( NOT TYPICAL ). WHERE THE FRONT AND REAR DOGBONES FROM THE TRANSMITION GO. PAGE 57 PART # 86095 ,PAGE 59 PART # 86094.

IF YOU CAN'T OPEN PDF LET ME KNOW ,I WILL ATTACH PICS.

 

[Goose1072]

If not that then you have blown diff my friend, not fun at all.