How to tell if my '75 K5 has a 2wd conversion? And additional questions.

[BloodMoon]

Hi all,

A while back (couple of years) I had a some work done to my truck by a family friend who is a mechanic.

He told me he put in a 2wd conversion in the transfer case (NP203) but took off the front driveshaft because I didnt have manual hubs yet; he said it would be better for the truck, and once I got the hubs installed, then I could put the front driveshaft in.

I finally got some WARNE Premium manual hubs installed, along with the front driveshaft.

I was pulling the truck out of the driveway and my father noticed that the front driveshaft was spinning. The hubs are in the "FREE" position, and the transfer case is in what should have been 2-HI (1 position back from nuetral).

I tried to rotate the shaft by hand, it moved a little but would come to a stop (about 1/8 of a turn, clock and counterclock wise rotation) I could hear what sounded to me the gears stopping it from rotating? The first part of the turn is really easy to do; I didn't try to spin it farther after it stopped.

So that is my story before my questions:

1. Does this sound like the 2wd conversion has been put in?

2. Any additional ways of testing?

3. Could I be shifting the transfer case through 2wd and straight into 4wd without knowing it?

4. Will it actually damage anything to run a 4wd transfer case with manual hubs?

Thank you for your help! and I hope one day I will be a significant part of this community.

 

[blazinzuk]

With a 203 and locking hubs in the unlocked position t case in hi if you didn't have a part time conversion the truck would not move. Neither would it with no front driveline. If the case was still full time you would have to be in hi lok to move without a front driveline

 

[BloodMoon]

With a 203 and locking hubs in the unlocked position t case in hi if you didn't have a part time conversion the truck would not move. Neither would it with no front driveline. If the case was still full time you would have to be in hi lok to move without a front driveline

Ahh! I see!

Could it be possible that it is still FULL TIME, and the nuetral position I thought it was in was actually HI and the HI position was actually HI LOC?

I guess I'll have to play with it after work tomorrow and see if I have what acts like 2 nuetral positions? and if this is the case, when it is in HI unlocked, if I were to look at the axle, it should be turning but the truck shouldn't be moving anywhere right?

and with this being my first 4X4; is it supposed to be really easy to shift the Transfer case?

If there is a kit in it, I wouldn't know what it is, but would the shift pattern be the same as everyone else's?
4 LO
2 LO
N
2 HI
4 HI

Thanks again!

 

[Stomis]

FYI this is commonly referred to as a part time conversion.

I would start by having a look at the case linkage while someone else shifts it.

 

[BloodMoon]

FYI this is commonly referred to as a part time conversion.

I would start by having a look at the case linkage while someone else shifts it.

Ok, what am I looking for when I watch it move?

And by linkage I think you are referring to the mechanism that the shift lever is part of?

 

[blazinzuk]

I do remember my front driveshaft spinning some as I was going down the road. Pretty sure I could rotate it freely though.

Been a while since I had a 203.

You are correct on the shift pattern. One thing with mine to find out for sure if the front axle was engaged was to get on a grippy surface ( my road works well for this, so would a parking lot) and turn full lock and do a couple circles. My front tires would always scrub if I was in 4 wd.

But if you can drive without the truck in the lok position ( hi or low) it has a part time conversion.

Remember the 203 basically has an open differential in it. So all the power goes to where the least amount of resistance is

 

[blazinzuk]

oh yah the shifters suck. Take it off clean it lube it and keep it lubed and it will work better. I got my old one shifting like what I imagine a new one would, very smooth

 

[BloodMoon]

Alright, So I just spent the better part of an hour figuring out that transfer case.

I have 3 positions that I can EASILY shift into when the engine is RUNNING, transmission is in NUETRAL and the hubs UNLOCKED.

I believe the following positions that I could shift into are:

LO (truck moves) with a part time kit, that should be the 2x4 LO
N (no move)
HI (truck moves) with the part time kit, that should be the 2x4 HI

The common concensus that I can find is that since the truck moved in those two positions with the hubs UNLOCKED it has a part time kit. right?

Now how do I shift into the 4x4 selections ? (LO/HI LOC)

and anyone have a definitive answer about the front driveshaft rotating? I watched the shaft rotate back and forth when cycled through REVERSE and DRIVE. (truck stayed stationary because the brakes were pressed in)

 

[Fordum]

OK, this is a little work, but should answer things once and for all. Take one end of the front driveshaft loose.
Unlock the hubs, try to turn the front axle input.
It should turn freely. If not, then you have a hub problem. If there is a clearance problem, or a binding spring, one or both of the hubs might not unlock.

If it turns, watch the U-joints in the ends of the front axle. They should both turn as you turn the input.
They may turn the same way or opposite, does not matter. If one does not turn, put a screwdriver or something in the other one and try again.
If it turns now, then the hubs are releasing.

You can also check to make sure they are locking by locking them and seeing if the axle locks.

Now, pull the transfer case lever all the way back. With the transmission in gear or park, you should not be able to rotate the front driveshaft output more than a small amount.
Bump it forward one notch, now you should be able to rotate it. If not, then I don't think the conversion was done.

In case the linkage is worn, try it in the two low positions also. Lo Lock no turn, Lo, turn.

If all that checks out, then don't worry about the shaft turning when you drive. Its quite common for one to do so. There is a lot of oil and grease friction in the hubs and transfer case, and often that is enough to cause the shaft to turn.

I have a set of Warn Premiums on the front seat of my truck I will probably put on tomorrow.
I tried to rotate the axle spline part inside the hub with it unlocked, and it was really stiff.
That may be what is rotating your driveshaft. Won't hurt anything, and will probably stop as it wears in.

 

[earnett]

Original shift pattern is
Lo lock
Lo full time
Neutral
Hi full time normal driving
Hi lock
Part time shift pattern is
4x4 low
2x4 low
Neutral
2x4 hi normal use
4x4 hi
With the part time kit the transfer case no longer has lock. The front shaft should spin freely in 2x4 lo & hi. It may still spin while driving due to friction.

 

[BloodMoon]

You are correct on the shift pattern. One thing with mine to find out for sure if the front axle was engaged was to get on a grippy surface ( my road works well for this, so would a parking lot) and turn full lock and do a couple circles. My front tires would always scrub if I was in 4 wd.

But if you can drive without the truck in the lok position ( hi or low) it has a part time conversion.

Remember the 203 basically has an open differential in it. So all the power goes to where the least amount of resistance is

Thank you,
I do remember my tires scrubbing occasionaly before this was done.

OK, this is a little work, but should answer things once and for all. Take one end of the front driveshaft loose.
Unlock the hubs, try to turn the front axle input.
It should turn freely. If not, then you have a hub problem. If there is a clearance problem, or a binding spring, one or both of the hubs might not unlock.

If it turns, watch the U-joints in the ends of the front axle. They should both turn as you turn the input.
They may turn the same way or opposite, does not matter. If one does not turn, put a screwdriver or something in the other one and try again.
If it turns now, then the hubs are releasing.

You can also check to make sure they are locking by locking them and seeing if the axle locks.

Now, pull the transfer case lever all the way back. With the transmission in gear or park, you should not be able to rotate the front driveshaft output more than a small amount.
Bump it forward one notch, now you should be able to rotate it. If not, then I don't think the conversion was done.

In case the linkage is worn, try it in the two low positions also. Lo Lock no turn, Lo, turn.

If all that checks out, then don't worry about the shaft turning when you drive. Its quite common for one to do so. There is a lot of oil and grease friction in the hubs and transfer case, and often that is enough to cause the shaft to turn.

I have a set of Warn Premiums on the front seat of my truck I will probably put on tomorrow.
I tried to rotate the axle spline part inside the hub with it unlocked, and it was really stiff.
That may be what is rotating your driveshaft. Won't hurt anything, and will probably stop as it wears in.

I may try doing this on tuesday or wednessday. I'll post up what I find out.

 

[BloodMoon]

oh yah the shifters suck. Take it off clean it lube it and keep it lubed and it will work better. I got my old one shifting like what I imagine a new one would, very smooth

2x4 Lo, Nuetral and 2x4 High shifted easily and solid, but 4x4 (loc) I cannot get it to shift into.

Would it be fine to spray it with some cleaner or CLP (for guns; cleaner, lubricant and preservative)?

 

[blazinzuk]

Sometimes cleaning with a spray type cleaner works. Mine it did for a while. I eventually took everything apart. Cleaned, replaced and adjusted the linkages. Cleaned the whole shift mechanism out . Took me a full day but it shifted great. I think you need to adjust your shift linkage

 

[COCHEV]

Sometimes cleaning with a spray type cleaner works. Mine it did for a while. I eventually took everything apart. Cleaned, replaced and adjusted the linkages. Cleaned the whole shift mechanism out . Took me a full day but it shifted great. I think you need to adjust your shift linkage

I've always had to take mine all apart too. They will never shift like a newer t case, but they aren't bad once you've cleaned it all up.

Lots of 203 questions lately. I remember they had such a bad rep. My only complaint is that they are frickin HEAVY!!!