slipping out of 4wd

[corelokt]

On the way home today, took the wife out for lunch, my 4wd began slipping into free wheel. Somewhere between 4wd hi and 2wd. It did it 3 or 4 times before it finally would stay and got us home.
Is there a shift linkage adjustment that may need to adjusted? I've also noticed of late my column shift needs to go past the drive detent to engage, then can go back to it and be fine.

 

[mangus580]

Your transfercase needs to be 'rebuilt'

Its usually the nylon shims that move the slide gears that fail, causing the symptom you describe.

As for your tranny shifter linkage... its probably out of adjustment slightly. Look under the master cylinder for hte linkage. You will see where the round rod goes through a square block with a bolt in it. Loosen the bolt, slide the block in the proper direction and tighten it again.

Although first you might want to check the pivot bushing on the frame down by the tranny.

 

[doghead]

Check your body mounts, your transmission/T-case and motor mounts and TMs.

 

[Dabba]

it wouldnt hurt to check the linkage, but yeah, shifter forks are probably worn

 

[Goatwerks]

Look for missing trans mount bolts at the adapter plate before fearing the worst
Very common

 

[corelokt]

Thanks all. It has me wondering because it's all really tight, as in no slop at all in any of the shifters.

 

[hobie237]

Mine sometimes does the same thing, but I know I have some slop in the linkage. When the truck was picked up, the 2/4 shifter was busted off, most likely from some genius yanking on it when the gears weren't lined up right to pull into 4 wheel. Replacement lever got it working again, but I've never bothered to adjust the linkage or anything. I find that if I pull it into 4H and then jiggle the lever side to side a few times, it won't pop out.

 

[HardCorps79]

Does anyone on here have a really smooth functioning transfer case? Every humvee and CUCV I've ever driven is a real PITA, even after recent servicing at the motor pool. What's the secret? (My "new" M1009 works, but again, requires patience, finesse and more patience).

 

[corelokt]

I didn't find anything loose or missing. I did adjust both of the shift linkages. Both the transmission and transfercase linkages adjustments came right loose and adjusted easy. That was a real pleasant surprise in a 23 year old NY truck.

 

[Goatwerks]

Does anyone on here have a really smooth functioning transfer case? Every humvee and CUCV I've ever driven is a real PITA, even after recent servicing at the motor pool. What's the secret? (My "new" M1009 works, but again, requires patience, finesse and more patience).

In short, they are all poorly designed. There are no syncro rings to allow smooth transitions between ranges.
When you change ranges the shift fork moves the entire planetary ring gear to mate or release from a fixed gear.
This is where the Europeans have used better options like full syncronization allowing shift on the fly.
The CUCV t case has a few weaknesses, but it is light weight and just strong enough for the application.
I prefer Unimogs and Pinzgauers , but have owned several(Blazer) civi versions both gas and diesel and know thier merits and weaknesses well.
One small trick to ease shifting between ranges is to first put trans in neutral and use one quick fluid movement . I learned this method years ago at the GM training center and now share it with this forum.

 

[kipman]

My m1009 goes into high range just like it should, no binding, low range is a different story.

 

[motormayhem]

Does anyone on here have a really smooth functioning transfer case? Every humvee and CUCV I've ever driven is a real PITA, even after recent servicing at the motor pool. What's the secret? (My "new" M1009 works, but again, requires patience, finesse and more patience).

Neutral makes it easy as pie to go into any range. Also helps if you are moving VERY SLOWLY.