I keep slipping out of 4HI ?!?!

[edpdx]

I just got back from a 7 day hunting trip. The first time I shifted into 4 HI, I would go a few yards under small loads and the Transfer case (TC) would make a loud grinding noise and then sound as if it were free wheeling. I would slow and place it in park and then shut her down. Upon restarting, it would be fine in 2WD, until I again attempted to crawl along, then it would slip out again. Otherwise it works as expected in 2HI or 4LOW.

I took it to a shop and the guy was able to swap it out for a recent rebuilt NP208. It too slipped the exact same way and only in 4HI. I finished my hunting trip in 4LOW.

What could the problem be?

 

[cliffyp]

If the new one is doing the same thing, it would seem like it must be your linkage, not setting fully in 4H

 

[edpdx]

how is that adjusted? Do I need to go to the shop?

 

[cliffyp]

You can check it yourself. It's all in the TM. Here's the first page:

 

[sf38a1]

I had a dana 24 that slipped out of 4 hi, it was a worn gear. if the gears get worn it puts an angle on them that causes them to jump out when a load is put on them .

 

[edpdx]

I took the Blazer back to the mechanic and he went for a test drive with me. We hammered it all to h3|| and could not get it to repeat. I did some googling on the matter last night and got some info on it. Many said that it may well be that the cab/shifter linkage may be banging against each other and to adjust the linkage as per the -20TM.

I'll start there. if that is the problem, I'm just hosed for the money ($1300)- I hate repairs like this when you are on a road trip.

The worse part is that the mechanic seemed very knowledgeable and sincere; but could not have made the adjustment before selling me the rebuilt he had handy.

 

[cliffyp]

Ouch! That sucks if it turns out to be just the linkage.