Np241 clicking

[heavy iron]

Noise when driving in-between cars. Took out drive shaft put in a spare yoke to stop the mess and turned the yoke when tranny in neutral and here a clicking coming from transfer case . Funny thing noise goes away when putting my foot on the brake . It's not the chain cause I'm in 2 wheel drive . Been. Reading it could be the pump in it or bearing . Looking for a replacement, truck is a 1990 suburban 4x4 with th400 np241 2500

 

[K85 Octane]

Have you tried all the Tcase settings? Just curious if it makes the same noise in 4H,L,N,2H

 

[heavy iron]

Haven't tried them all just in high with the transmission in neutral .