np208 won't shift to neutral or 4 low

[WebMonkey]

hello all.

1985 k20
350 m code engine
4 spd manual
np208
14 bolt semi float rear

i bought this truck from my son, it gets worse every time i go out to the garage to 'work on it'.

first problem i'd like some input on:

1) the transfer case refuses to 'go into' neutral (and therefore not reaching 4 lo either).

the shifter moves well between 2/4 hi.

i move the shifter toward the passenger door and pull down/back.
the shifter moves a small amount but never 'lets go' of the transmission.

i jacked one rear wheel up so i could spin the driveshaft a bit.
didn't help. i've pushed, pulled, rotated etc for a couple days on and off with no luck.

the shifter/case will go right back up/forward to the hi range without trouble.

what should i look for?

transfer case in neutral is important to me as i plan on towing 4 down as i do with my 2005 dodge ram.



2) there is a 'pigtail' coming from the transfer case shifter console and hanging free above the transfer case. 2 conductor locking plug.

any idea what that is for? neutral light or other indicator?

thanks for your time.

 

[Frankenchevy]

The plug is for 4wd indicator light on your dash. Should plug into the top of your transfer case.

The plastic inserts for your range forks may be damaged or missing.

 

[WebMonkey]

thanks for the reply.

i was afraid the case would need 'some work'.

i don't think anything on the truck is going to be left untouched.

'preciate it.

'monkey

 

[Rusty Nail]

Is the trans in neutral when you want 4Lo?
It still no-go?

i'm not convinced.

 

[WebMonkey]

yes, transmission stick is free/not engaged in any gear.

i've tried clutching while transfer case shifting also.

the transfer case stick will move toward neutral (pushed to passenger door and down) but never makes it to neutral.

 

[WebMonkey]

yes transmission stick 'free'/not engaged in any gear.

i've tried motor running, motor off, clutching the transmission, as well as what i listed above.

the transfer case stick moves toward neutral (stick pushed toward passenger door and moving down/back) but never makes it to neutral.

 

[Rusty Nail]

oh yeah, manual.

 

[RoryH19]

Had the same setup in my 86 k20.
4 low was always stiff to shift into.
Sometimes clutch in, sometimes trans in neutral. Sounds like you already tried moving forward if you turned the driveshaft.

May have to drop the case and take a look inside .

As mentioned above the connector is the 4 wheel drive indicator on the dash.

 

[WebMonkey]

thanks all.

i've really jumped in the deep end.

my shade tree mechanic experience has been with motorcycles.
inline fours have been my wheelhouse.

hopefully i can follow instructions with this much larger project and have good results as well.

 

[71RAT]

90% of the NP208 fork issues are caused from a missadjusted shifter. That being said, did you disconnect the shifter and try to put it in 4 lo under the truck! Make sure there's no tension on the drive line, unlock hubs jack up rear. You can wiggle the driveshafts aas you more the lever. These tcases are very basic, don't be intimidated.

 

[donnieray]

There is a possibility that some one has installed mounting bolts that are too long and interfering with the shift fork mechanism. It's not uncommon because the threads in the aluminium housing can get stripped and a longer bolt will contact some good threads and fix one problem while creating a much bigger one. I will never forget this as it cost me a thousand bucks to learn the lesson. Pull the top bolt out and any other one and compare them. They should all be the same size. I put a longer bolt in the top hole, drove the truck a month or so before trying to shift into four low and it was hitting solid right about the neutral position. I ordered a rebuilt case, waited for the time off work, installed the new unit and it had the same problem. It took about eight beers worth of deep thought to figure it out. So I have a spare case now and I'm a little bit smarter. If this dont help you maybe it will help some one else. Good luck man. The bolts should all be either 1-1/2" or 1-1/4", I cant remember but surely all the same length.

 

[WarlVlachine]

Honestly, the case is not that tough to work on. It's intimidating, but it all goes together pretty easy. There is actually a really good youtube playlist of someone doing a complete rebuild. It helped me on my first one. @71RAT had it right, that's what I would check first. Simple stuff first!