Transfer case noise

[85chevy350]

Just bought an 85 chevy k10 with a 350 and one of the locking hubs was busted so i ordered 2 warn premium locking hubs offline and saved like 60 bucks.Then after i put them on i went out to try them out. The hubs were fine but there was a knocking noise coming from somewhere around the transfer case.
Any ideas??

 

[crazy4offroad]

Check your front double cardan joint, if you had it in 4WD and it was doing it. If it does it in 2WD with the hubs unlocked check the rear driveshaft u-joints.

 

[Beatdown Z]

Def check u-joints and check t-case oil level.

If it's a NP208/241, NEVER run it low on oil.

 

[78shortandwide]

i would agree with crazy its most likely your carden joint in the front drive line that sounds just like the noise mine made when it broke last weekend

 

[85chevy350]

not too sure where or what a cardan joint is?
also have another question. are valve cover breathers a good idea?
what does it really do?

 

[crazy4offroad]

The double cardan joint is the 2 u-joints in a weird looking coupler on the front driveshaft closest to the transfer case. Valve cover breathers allow positive crankcase vacuum, and NO crankcase pressure, which can result in oil consumption and bad performance.

 

[85chevy350]

Thanks for your help i will be looking into it