203 Issues.

[Heavy]

I have a '74 Blazer. Its a 350/TH350/NP203/D44/12B set-up. It started life full time 4X4 as all 203 equiped trucks. My issue is the partime kit is starting to screw up. Its not keeping the front wheels turning in 4Low. Its rock solid in 4High but soils the sheets bad in 4X4 other wise. 2Low works like a dream as does 2High and well Neutral is Neutral. My question is what is the cause/solution to this problem. I am looking for the cheapiest solution. I know MileMarker (among others) makes a couple kits that convert the 203 to parttime but one is weak (k, not weak but flawed) and the other is expensive as hell. I have been researching this and I wanna know if "Lincoln Locking" (welding) that differential thing on the rear output would work. Everything I have read says that that piece is just like a diff in an axle. And the "L-Lock" is one of the cheapest and strongest lockers for a differential I have ever seen. Anyone know of "Lincoln Locking" the output shaft working, or any tips on a better way to deal with this issue??

I don't wanna hear a lot of "just get a 205" lines I wanna solve this 203 issue first.

 

[dremu]

'Fore you go welding and tearing the case down, read up on adjusting the shifter. I've never messed with 'em myself, as one of mine I just bungeed to the seats, the other's been replaced by a 203/Doubler/205.

However, I gather the factory shifter is prone to getting out of whack, having several moving parts.

I'd also check and make sure your front locking hubs are in fact locking; if they aren't, it won't matter what the transfer case is doing

-- A

 

[BRIAN THOMAS]

'Fore you go welding and tearing the case down, read up on adjusting the shifter. I've never messed with 'em myself, as one of mine I just bungeed to the seats, the other's been replaced by a 203/Doubler/205.

However, I gather the factory shifter is prone to getting out of whack, having several moving parts.

I'd also check and make sure your front locking hubs are in fact locking; if they aren't, it won't matter what the transfer case is doing

-- A

This info is very true.

 

[Heavy]

the hubs are 100% locking...its the first thing i checked...and they are also locked in 4High...i can only assume its the t-case.

 

[dremu]

the hubs are 100% locking...its the first thing i checked...and they are also locked in 4High...i can only assume its the t-case.

Enjoy sorting out the shifter; as I recall they're complicated.

If you really like your '203, you might look at the twin stick kit for it.

-- A

 

[Zeus33rd]

The 203 shifter is an overcomplicated pile of sh!t. Just like the rest of the tcase.

That said, take the entire shifter off the rig, disassemble it, clean it and put it back together, reinstall/adjust. You'll be blown away at how much easier and better it works. Read up on adjusting tho, I too can remember that being complicated.

And just to be the first one to say it, ditch that pile of sh!t and get a 205.

 

[Heavy]

i am looking in to a twin stick...but i mainly need to know if the welding of that differential thing is doable...

 

[Zeus33rd]

i am looking in to a twin stick...but i mainly need to know if the welding of that differential thing is doable...

I don't see why it wouldn't be doable, but I know pretty much nothing about the tcase, beyond how to take the shifter apart and how to separate the range box. And I really doubt the differential is part of your problem...you said it yourself, the thing works in hi-loc. The low/hi part of the tcase is governed by the shifter....

I think you'd be better served by taking a look at the shifter, fixing it, then making some plans to replace the entire thing at some point down the road.

 

[75GmcJimmy4x4]

I have a '74 Blazer. Its a 350/TH350/NP203/D44/12B set-up. It started life full time 4X4 as all 203 equiped trucks. My issue is the partime kit is starting to screw up. Its not keeping the front wheels turning in 4Low. Its rock solid in 4High but soils the sheets bad in 4X4 other wise. 2Low works like a dream as does 2High and well Neutral is Neutral. My question is what is the cause/solution to this problem. I am looking for the cheapiest solution. I know MileMarker (among others) makes a couple kits that convert the 203 to parttime but one is weak (k, not weak but flawed) and the other is expensive as hell. I have been researching this and I wanna know if "Lincoln Locking" (welding) that differential thing on the rear output would work. Everything I have read says that that piece is just like a diff in an axle. And the "L-Lock" is one of the cheapest and strongest lockers for a differential I have ever seen. Anyone know of "Lincoln Locking" the output shaft working, or any tips on a better way to deal with this issue??

I don't wanna hear a lot of "just get a 205" lines I wanna solve this 203 issue first.

do you know for a fact that you have the part time kit as i have a 75 and was told it was coverted and to find out all that was done is there are manual hubs and it was driven in high loc ....

 

[rufusbooth]

I will echo others comments here. I am 99.9% sure your problem is not with the part time kit. If you had a part time kit problem your truck would not have any drive when the front hubs are disengaged and in 2hi OR 2 low. With no part time kit installed (or a failed part time kit) the drive power would be output to the drive shaft with the least traction just like an open diff in a rear end.

That being the case, I would be willing to bet you have a shifter issue. You can test this theory fairly easily. It has been a while so my description of lever positions may be off a bit.

Transfer case description:
your transfer case has 3 parts.
1. furthest forward (range box, Hi, neutral, Low)
2. Middle (chain drive to front drive shaft and 2wd 4wd selection)
3. Rear (differential and rear output section)

Your shifter is mounted to the front of the transfer case adapter.
It has two links that go back to the transfer case.
one to the range box (front)
one to the chain drive housing (middle)

you will want to disconnect the links on the transfer case side of each link. They are held on by cotter pins. Remove the cotter pins and remove the links so that you can manually operate the levers that go into the transfer case. This isolates the shifter from the transfer case.

The front lever on the range box has 3 positions.
lever pointing forward. (High Range I think)
lever pointing straight up and down. (definitely Neutral)
Lever pointing back. (Low Range I think)
This lever controls 2 things only. Hi/low range and neutral.

the rear lever on the chain drive case (middle) controls 2wd or 4wd only and has two positions.

Lever pointing forward.
lever pointed back.
Not sure on the position of these two but when you are in 2wd and the front hubs are unlocked you will be able to rotate the front drive shaft by hand.

Simply flip the front lever into low and the back lever into 4wd and see how it works. There should be a distinctive click when the levers are in their proper positions. My guess is the tests will be flawless. If so, remove and R&R the shifter and reinstall.

It goes without saying that when messing with the levers safety first! engine off, parking brake set, and blocks on both sides of the wheels.

Hope that helps.

Cheers,

Rufus

 

[Heavy]

thanks booth....i will have to try that...i also think that i may do the welding just to completely eliminate any slippage or weak link...but i will try the shifters first...and i am sure that i have a part time kit installed...i can shift it in to what should be H (High) on the original shifter boot (not HLoc) and the front drive shaft does not spin...so i do have a 2High setting...anyone know of a company (preferably Canadian) that sells a respectable and respectably priced twin-stick kit???...i then can eliminate all this crap...

 

[broke73]

Np 203

I think that you will find the problem is the differential carrier. You could weld the differential side shaft to it but you still would not be able to engage the sliding clutch gear which puts the t-case into 4 wheel drive. On mine the differential carrier teeth were worn down this caused the front diff to work only when it wasn't under a lot of load (like 4 low). Eventually the teeth completely wore out and good bye 4 wheel drive.

I would open the case up and inspect it. If this is the problem order one from http://www.midwesttrans.com/ they're pretty good on there prices.

Here's a diagram so you can see what I'm talking about.

 

[rufusbooth]

Heavy,
Sorry man, I was totally off on the description I gave you (it has been that long since I looked at one). I got some pictures of the shift linkage and the proper positions so I will post them up for you tomorrow.

Long story short, the two shift linkages are on the same shaft. The shifter right next to the case is the 2x4 and 4x4 selector. The one closest to the passenger side of the reansfer case is the high/low range selector.

to be in 4x4low both shift levers need to be pointing forward. Like I said I will upload pics tomorrow morning showing the positions.

Cheers,

Rufus

 

[Heavy]

Thanks again rufus,

I am looking into getting 2 shifters and making a homemade twinstick and your info has been very helpful.

wheel hard, but tread lightly,

Heavy