interesting np203 part time kit issue

[Amahoser]

Im not totally sure if I have a part time kit or not since i've only had this Blazer for a week. It does have manual hubs so I just assumed it had a part time kit.

When I bought the truck, the PO only had it 3 years and he was not very familiar with the 4wd system. He pretty much kept it in 2wd mode. The transfer case was stuck in 2wd when bought.


I unstuck the transfer case last week by cleaning all the grime and wd-40'ing the linkage... ok figured that would solve it. At that point, I could shift from 2wd high - neutral -2wd low. But that was it.... so I guess I wasn't done yet.

After reading a few posts on this site, I decided to try to adjust the linkage. I found that the inner most lever on the transfer case was angled forward (towards front of truck) when the shifter was in neutral. I reset the lever and adjusted the linkages.

Now, the transfer case behaves like there is no part time kit installed.. When hubs unlocked...

Low Lok - drives
low - truck don't drive
N
High - truck don't drive
High Lock - drives

Seems odd that someone would install manual hubs but not the part-time kit.

Questions....
- CAN the linkages be adjusted in a way that there is only 3 positions (low lok, N, high lok)? Is that what was done to this truck???
- IF I do have a part time kit, could mine be broken in a way that makes it act like it doesn't have a part time kit?
- running in high lok with the hubs disconnected is fine right?
- IF i do have a part time kit, is there a ritual or a procedure that needs to be followed in order to switch from 4wd to 2wd mode??? (like drive it in reverse for a bit or doing a 2wd dance outside the truck before unlocking the hubs)
- what is that dance (I have no rhythm, btw)

Thanks
Jose Soriano

 

[Hogback Fabrication]

Sounds like you don't have the part time kit, just a regular 203.

I've heard that driving for long periods of time in high-lock with the hubs unlocked can be bad for the t-case in the long term.

 

[Muddytazz]

Nope, you do not have the part time kit installed.

 

[Amahoser]

Thats what I figured, Interesting that the transfer case would only shift from high loc to low loc before I adjusted it....

Hmm... its bad to drive with the hubs unlocked? Ok, I guess i'll lock the hubs and keep it there. Seems that if I want 2wd it might be better to just change out the transfer case instead of converting a 203... that way i'd be rid of the chain drive front that people complain about.

still reading and learning about these K5's....

Thanks for helping out a noob

Jose Soriano

 

[4X4HIGH]

DO NOT drive with the hubs locked on pavement or something will break. NP203's are a fulltime 4wd transfer case so there is no 2wd setting for it. When a part time kit is installed it allows you to unlock the hubs and leave the t-case in either Lo or Hi position but the front shaft will still spin.

In the current state of your t-case if you lock the hubs and drive it in hi-loc or lo-loc both the front and back diff will spin at the same speed and something will break if it's on a hard surface. When the NP203 is in the hi or lo position but not lock then the differential in the case allows the front and rear axle to spin at different speeds which theoritally would be ok on a hard surface but without the part time kit you cannot drive it in those positions as you've already figured out.

 

[Amahoser]

DO NOT drive with the hubs locked on pavement or something will break. ......

Sorry, I mispoke. I know not to drive in lock mode on pavement. I meant that I would lock the hubs and drive in High mode (not high lock). But thanks for the warning. I was referring to the earlier comment that leaving the hubs unlocked and driving in High Lock could be bad for the transfer case. I'm actually not sure about this because the previous owner did just that for three years. Wonder if any harm was done.... But to be safe, i'll just drive with the hubs engaged and in High mode.

 

[imiceman44]

Sorry, I mispoke. I know not to drive in lock mode on pavement. I meant that I would lock the hubs and drive in High mode (not high lock). But thanks for the warning. I was referring to the earlier comment that leaving the hubs unlocked and driving in High Lock could be bad for the transfer case. I'm actually not sure about this because the previous owner did just that for three years. Wonder if any harm was done.... But to be safe, i'll just drive with the hubs engaged and in High mode.

Yeah I did that for a while on my first truck and in my case I burned up the locking hubs, I guess since the shafts are still turning but not necessarily at the same speeds it burned up the plastic

 

[SUB602]

Why not remove the front driveshaft until you get a part time kit installed? I just purchased a 78 for parts and the PO had selectable hubs and no part time kit. It seems he was driving it without a front driveshaft. Just a thought.

 

[4X4HIGH]

Sorry, I mispoke. I know not to drive in lock mode on pavement. I meant that I would lock the hubs and drive in High mode (not high lock). But thanks for the warning. I was referring to the earlier comment that leaving the hubs unlocked and driving in High Lock could be bad for the transfer case. I'm actually not sure about this because the previous owner did just that for three years. Wonder if any harm was done.... But to be safe, i'll just drive with the hubs engaged and in High mode.

The truck won't move without the part time kit installed if the t-case is in the high mode, only high-loc or Lo-loc will it move.

You posted this yourself...

Low Lok - drives
low - truck don't drive
N
High - truck don't drive
High Lock - drives

 

[imiceman44]

The truck won't move without the part time kit installed if the t-case is in the high mode, only high-loc or Lo-loc will it move.

You posted this yourself...

But if he locks the hub it will.
That was with hubs unlocked.

 

[Amahoser]

Yep thats my point... If I engage the manual hubs (lock) and leave it there, my truck will act like a full time 4wd. I can then drive in high 4wd not locked. That should be safe. Right?

I don't mind keeping it in 4wd since its not a daily driver. I guess i could remove the driveshaft but, like I said, I won't drive the truck everyday. Besides driving it to the trails, it will only see pavement use once in a while.

I'll probably convert it to part time in the future or better yet, switch to a 205. But thats a ways away... prolly if/when i blow up the 203

Jose Soriano

 

[Amahoser]

The truck won't move without the part time kit installed if the t-case is in the high mode, only high-loc or Lo-loc will it move.

You posted this yourself...

you missed the line just before... "When hubs unlocked"

Jose Soriano

 

[4X4HIGH]

Yep, i missed that part. You can't pull the front shaft though or it won't move unless you have it in the loc position.

 

[Desert Yeti]

Seems like you've got a stock 203 with no kit (as already stated). As also stated in the various posts above, if you LOCK the front hubs and drive in High UNLOCK on the T-case, you're essentially doing what the truck did off the showroom floor in '73. Especially for a non-daily driver (and if a bit more gas used isn't a big deal), you're totally fine driving it around this way as much as you like.

You could also UNLOCK the hubs and drive in High LOCK, but this spins all the front axle parts except the hubs and may cause problems with reliability eventually.

I would suggest either a kit or a 205 eventually, but in the meantime, work on your other plans (suspension and such) first and worry about the t-case later... it's fine for now!

 

[BlazerBud]

Most people have answered you too hasty. I have the same np-203 and mine has the part time. One thing that you may not be doing is shoving the lever all the way. Mine was stuck like you describe, and When I finally fixed it, the lever swings almost 1 foot front to back. The shift pattern that you described is not correct. When you think you are in low or high and not locked, you may still be in neutral. You haven't gone all the way to low lock or lock when you think you have. Here is what stock should be:

Low Lock--------4wd low lock for off road
Low-------------4wd low (not locked similar to all wheel drive) for street
neutral----------neutral
High-------------4wd high (not locked similar to all wheel drive) for street
High lock--------4wd locked for off road

Part time kit:

Low lock---------4wd low lock for off road
Low-------------rear wheel drive low
neutral----------neutral
High------------rear wheel drive high
High lock--------4wd high for off road

Your description to me sounds like my first mistake. I didn't put it all the way in gear. If you have manual hubs, that is also suspect that part time was installed, not definite, but suspect.

The only real way to tell if you are in 4wd gear is not to drive the truck, but get underneath and see if you can spin the front drive shaft by hand, hubs unlocked off course. The part time kit makes it MEGA hard to go into gear, so the shifting is tough. I always had to have the truck level, no load on brakes or driveline to shift the transfer case. ANd it took some hard jerky shoves to shift it.

Good luck.

 

[imiceman44]

Most people have answered you too hasty. I have the same np-203 and mine has the part time. One thing that you may not be doing is shoving the lever all the way. Mine was stuck like you describe, and When I finally fixed it, the lever swings almost 1 foot front to back. The shift pattern that you described is not correct. When you think you are in low or high and not locked, you may still be in neutral. You haven't gone all the way to low lock or lock when you think you have. Here is what stock should be:

Low Lock--------4wd low lock for off road
Low-------------4wd low (not locked similar to all wheel drive) for street
neutral----------neutral
High-------------4wd high (not locked similar to all wheel drive) for street
High lock--------4wd locked for off road

Part time kit:

Low lock---------4wd low lock for off road
Low-------------rear wheel drive low
neutral----------neutral
High------------rear wheel drive high
High lock--------4wd high for off road

Your description to me sounds like my first mistake. I didn't put it all the way in gear. If you have manual hubs, that is also suspect that part time was installed, not definite, but suspect.

The only real way to tell if you are in 4wd gear is not to drive the truck, but get underneath and see if you can spin the front drive shaft by hand, hubs unlocked off course. The part time kit makes it MEGA hard to go into gear, so the shifting is tough. I always had to have the truck level, no load on brakes or driveline to shift the transfer case. ANd it took some hard jerky shoves to shift it.

Good luck.

I have the part time in mine and just like when it was a full time, the best way to shift it into lock is on the move.
If you are doing it stopped, it's always hard, these were made to shift into lock on the fly, the low range from high range has to be stopped and tranny in neutral.
You are right though about him possibly having this problem.