Slipping from 2H into 4H? NEED HELP ASAP!!!!!

[tksuburban]

I'm having a problem I have an '87 V10 Suburban with a NP208 T-case, 700R4 and 10 bolt axles. The problem I'm having is that while driving I start to hear a real loud clicking noise come from the LF wheel. Almost like a bicycle freewheeling. I'm almost positive that it's the crappy auto locking hubs trying to engage. But they shouldn't be if it's in 2H. It's like it's partially engaging. When I actually throw it into 4H everything goes back to normal. It's not a poping noise. It's when I first start off that I start to hear it and as I start putting the shifter into 4H, it starts to go away. When 4H is fully engaged it's gone. Then I'll through it back into 2H and it's ok. But after I back up it starts to do it again. So I think that my t-case is somehow working it's way into 4H or not fully going into 2H, trying to allow the hubs to engage. Almost like it's not locking out in 2H. Is this something that can be fixed with an adjustment or do some hard parts need to be replaced? I've got new manual locking hubs that I'm going to be putting on and that would prevent this from happening. But that's not truly fixing the problem. I don't want the front axle to always be engaged. I need to know what to do. Any help would be appreciated.

 

[dave_90_blazer]

sound like the detent spring/ball/plate in the t-case is worn

 

[tksuburban]

Could it possibly be just an adjustemnt that needs to be done? Because I'm having the same issue when it's in 4H. It will fall out of 4H back into 2H. See this is my daily driver and I'd like to try everything that possibly might fix it before I tear into the internals of it. /forums/images/graemlins/burb.gif

 

[R72K5]

yes those auto hubs can be doing that in 2wd, ive seen many do it and my stepdads 82 does it, get some warns asap, my stepdad is oblivious and wont get manuals for it cuz he is against having to get out of truck, so when a hub blows up on him i will ROFL at him because he is stupid and i always laugh at stupidity

i would check linkage on case and make sur eis not caked with mud and crap, clean around linkages good

 

[dyeager535]

Wouldn't even bother diagnosing the hubs. They are a KNOWN problem, and really should be discarded.

I used old factory spicers to replace mine, happy so far.