I have an 85 K20 diesel Suburban, and the transfer case (NP-208) in my Burb is stuck in 4wd for the 2nd time in less than 2 weeks. I figured the 1st time was because I didn't check the linkage adjusment after I converted over to an SM-465. That time the chain snapped and took out part of the case with it. I found a replacement and got that installed and readjusted the linkage according to the Haynes manual. This morning, on my way home from work, I noticed it was stuck in 4wd again. Fortunately, I got home before the chain snapped, but I think there might be some internal damage...there were 3 sharp jolts while I was driving. Anyways, I am totally confused as to why this is happening. I know my tires are out of balance (can really feel it at 65 mph) and I was planning on replacing them tomorrow. That now will wait until I get the t-case figured out, but I will have the newer tires put on before I drive it again. Could the out of balance tires be the cause of my transfer case problems? I haven't pulled the t-case yet so I'm not sure what the damage really is. Any other ideas or things I should check? Also, my friend gave me the old manual hubs from his K5 Blazer...he upgraded to Warn Hubs. Can I use those hubs on my Suburban even though my Burb is 3/4 ton and the Blazer is 1/2 ton? Do I have to worry about a spindle nut conversion kit? I really want to get rid of the autolocking hubs. Any help will be greatly appreciated. Thanks!!!