203 transfer case problems
 

I have a 4x4 with a 203 transfer case with lock out hubs and I think it may have been converted but don't know for sure, anyways I was using 4x4 and while driving slowly the front wheels locked up and would not free up and I couldn't get the transfer case back to 2wd so I kept trying to backup and go forward and it freed up and made a pop sound and now the 4x4 will not work, I can lock it into 4lo and it will reduce the gears but no power to the front wheels. Now I haven't tore into anything yet but what do you guys think the problems could be or could have caused this? any tips would be great.

Re: 203 transfer case problems
 

Prolly chain......

Re: 203 transfer case problems
 

is there a way to check before I remove it?

Re: 203 transfer case problems
 

Not sure if there is an inspection cover to see chain or not. Pull the PTO cover, maybe that will give you enough to take a look see.

Re: 203 transfer case problems
 

How do you know when it's in 2WD? The 203 is supposed to be full time 4WD.

Re: 203 transfer case problems
 

I believe the 203 was converted since it had lock out hubs and when I shift too 1 click below N on the transfer that would be 2wd on my truck.

Re: 203 transfer case problems
 

You won't see much if you pull the pto cover x'cept a fat bull gear. On the rear of the case there is an aluminum cover, 8 bolts holding it on. After you drain the oil remove the 8...... 9/16'' headed bolts. Slip in a putty knife and work around the plate. Get ready to catch a quite a few needle bearings that may fall out of the pocket that supports the rear of the front drive gear. From there you can see part of the chain and possibly determine the damage if any.

Re: 203 transfer case problems
 

Were you driving on pavement when things got weird? You don't drive on pavement with the hubs locked in 4x.

Re: 203 transfer case problems
 

If it's a 203 kinda dont' have a choice, part time kit or not.

Re: 203 transfer case problems
 

No I wasn't on pavement, but if I was I don't see what pavement would have to do with it.

Re: 203 transfer case problems
 

One more thing, if the chain is broke would it still reduce the gears when in 4lo?

Re: 203 transfer case problems
 

You might have better luck in the 4x4 part of the forum http://67-72chevytrucks.com/vboard/f...splay.php?f=30

Re: 203 transfer case problems
 

If you run a converted NP203 in 4wd or a stock case in LOC on pavement the transfer case will bind up. Drive it in reverse with the hubs locked in til you can shift her. It may make nasty noises when she finally condescends to shift but I doubt you really hurt it. You have to work at it to kill a 203.

If the chain broke the case would bind up and stop no matter what position you set the shifter in because it doesn't ever stop turning. She would make a heckuva racket driving too.

You can twin stick a stock NP203 and they work a LOT BETTER. I did one years ago on a 1979 Dodge 3/4ton Power Wagon.
Stick 1 is HI-N-LO.
Stick 2 is LOC and AWD (not locked). AWD on pavement and LOC when you need traditional 4wd.

Re: 203 transfer case problems
 

It made a pretty loud pop when the front tires finally unstuck and I tried backing up but the front wheels wouldn't roll at all until the pop noise, now no power is getting to the front wheels, i can drive it no problem without any noise at all just no front wheel action when I shift too loc.

Re: 203 transfer case problems
 

Some of the part time kits had a pretty bad rep for weak internal parts. However it should be making nasty noises even in 2wd. You can get to most of the diff parts by pulling the tail housing.
If it really isn't working you'll have to pull the case out to fix it or replace it.

If the 203 isn't making nasty noises in 2wd I'd be tempted to rule out the front axle. Set the front axle on Jackstands and see if you can turn the front propshaft with the transfer case in 2wd or neutral. Maybe even pull the front propshaft off the diff and or transfer case flanges and see if the front wheels will turn with the hubs locked in.
If they don't turn pull the diff cover off the front axle and take a gander.

Re: 203 transfer case problems
 

How do you know that no power is getting to the front wheels?

One thing you can do that is easy is put the front hubs in free, and have someone drive a few feet in HI while you look from the side. A part-time 203 won't spin the front shaft. Now do the same thing in HI LOC. The front shaft should spin if the 203 is working.

Re: 203 transfer case problems
 

I will try these test out in a couple of days since its really cold here now, also I know the front end isn't getting power because I was in 4 loc going through some mud and almost got stuck and was spinning trying to get out and only the rear wheels where spinning.

Re: 203 transfer case problems
 

Very possible the front diff is broke..easy to check..just pull the cover and look...and if its got manual hubs one of them could be broke...I had one disintegrate on my ol 72 one time..well ..I see hatzie was already pointing towards that

Re: 203 transfer case problems
 

When I lock the hubs I can't spin the axle going to the wheels and I can with them unlocked, so I assumed they were working, also I had thought of the front diff but I figured it would be making noises while I'm driving. I'm going to check that out with a few of the other things and if I can't find anything, I guess I will have to take it too a shop. Thanks for the help it's really appreciated.

Re: 203 transfer case problems
 

This sounds more like the front axle. Unlocking the hubs literally disconnects the axle half shafts from the hubs so if there's a problem that's locking up the diff it will not rear its' ugly head with the hubs unlocked.

Can you spin the wheels or the front prop shaft with the hubs locked and the transfer case in Neutral?

Re: 203 transfer case problems
 

Can you spin the wheels or the front prop shaft with the hubs locked and the transfer case in Neutral?[/QUOTE]

I will try this and report back, all this happened a few weeks ago and i'm just now getting around to messing with it but seems like I tried spinning the front shaft and it would with hubs unlocked but with the hubs locked I couldn't spin it but its been a few weeks so I will re try this, also I can drive the truck with the hubs locked now and it won't make any noises at all, it just won't go into 4x4.

Re: 203 transfer case problems
 

It's not going to spin with the hubs locked unless you end up rolling the truck at the same time

Re: 203 transfer case problems
 

It needs to be up on jack stands to get the wheels off the ground. I didn't state that.

Re: 203 transfer case problems
 

I will do it this weekend and report back.

Re: 203 transfer case problems
 

Ok here's what I have so far... hubs locked with transfer in neutral I can spin front shaft no problem and this is with front wheels off the ground and transmission in neutral or drive either one. I also tried to spin the shaft with transfer in 4hi and cannot spin it and I can spin the front tires and the front shaft doesn't move. What do you guys think?

Re: 203 transfer case problems
 

Ok now I put the truck on jack stands and put it in 4x4 and had someone watch the front shaft with it in gear and the front shaft would turn but the front wheels won't, so does this just leave the hubs as the problem?

Re: 203 transfer case problems
 

Hubs or differential, I think. Hubs are more likely. A good set of Warn 9790 hubs are 100 bucks a pair at Summit. That's cheaper as a first step than doing anything with the diff.

Re: 203 transfer case problems
 

Well I found the problem the cross pin bolt had evidently backed and the cross pin slip down and broke.

Re: 203 transfer case problems
 

Did it break the carrier or just mangle the cross pin?

Re: 203 transfer case problems
 

It broke the cross pin but I had one from a 70 nova that I had fixed and I'm putting it all back together now.

Re: 203 transfer case problems
 

Maybe clean the threads with a small amount of solvent and assemble the lock bolt with a dot or two of Loctite 243. Then let it cure 24hours before filling with oil and driving.

Loctite 243 is oil resistant Loctite 242 is not.