Trans fluid into transfer case

[OZRY83]

Have an 1988 GMC K2500, filling transmission with fluid it goes into transfer case and tranny slips because of low fluid. What seals do I need and gaskets. Trying to get parts first before taking apart.

[Logan Lanfear]

Could be the input shaft seal, dirt cheap but a pain of a job.  

[OZRY83]

Well got transfer case out and replaced the cracked input seal on transfer case. Yaw, def not a fun job to do in driveway at night in 42 degree weather with wind. Changed pan gasket and filter on tranny too. Did not find a paper gasket for input shaft used grey rtv. Removed rear seal to go to rear axle but didn't get sold correct seal, so its back to parts store, then finish job, hopefully it will be moveable before snow!!

[OZRY83]

ohhh National oil seals 710928 is input shaft seal for 88 gmc k2500 with 700r4 and NP241C.