I need help

[ilovemytruck]

Hey guys, i got a problem with my truck. Its an 85 k5 with a 305/700R4/NP208. I just put new manual locking hubs up front, as i thought it would help the constant knocking in 4wd, obviously it didnt. The thing knocks and clunks like you wouldnt believe. Im beginning to think its that God awful 208 in between my driveshaft and tranny. Im just wondering if anyone has had similar problems to verify weather or not its the transfer case. If it is indeed, i would like to slap a 205 in its place. Any feedback is apprieciated.

[79GMC4x4]

You checked the obvious stuff, like u-joints?  By the way, welcome!

'79 GMC shortbed 454 th400 14 bolt FF NP205 Dana 60

[ilovemytruck]

I checked the u-joints, but not the axle joints. I have no idea how to do that, but i dont know if they would cause that noise.

[83CHEVY]

I doubt the transfer case would make a noise like that.  It is obviously something that moves only when the 4WD is engaged.  So look at the front driveshaft U-Joints and the front axle U-Joints.  It could possibly be in your front differential also (chipped teeth?).

Mike

[76L88]

Don't forget to check the drive shaft slip joint if it has one.  Work it up and down and see if there's any play.