Keep NP203 or ???

[sweetk30]

H1’s actually use AMC 8-7/8” inverted diffs ( instead of Dana ) to work with the two-gear portals and no planetary at the hubs.

Yaa been a bit from when i read up on them got names mixed up .

 

[73K5BlazerSS]

Humvee is also planitary hubs at wheels so a lot less load on driveline . And the dana center diffs are 28 or 30 size mid 2:xx ratio . . . Oh and 6.2/6.5 raw power

That's really cool I've never seen that before. I guess that's kind of like a portal axle.

 

[sweetk30]

That's really cool I've never seen that before. I guess that's kind of like a portal axle.

There is a 67-69 camero body on a h1 platform with big motor LS and he used spare front end parts in rear and its 4 wheel steering . Go search youtube it will blow your mind .

 

[73K5BlazerSS]

There is a 67-69 camero body on a h1 platform with big motor LS and he used spare front end parts in rear and its 4 wheel steering . Go search youtube it will blow your mind .

I think i found it, a 68 called "MudMaro" or "The Honky Donk". It looks pretty wild. I never knew the H1 suspension was so badass, and so easy to change to 4 wheel steering. The portal gears provide a 50% reduction. The guy built it in 30 days!

 

[Chickntrk]

Are you looking to sell it? I think you're in the northeast right?

Im in central PA, If someone wanted it I would sell it. Wrong input for you though, it would be 32 spline.

 

[JohnNoble]

I'm not sure how accurate the info I gathered is but here it goes. Supposedly in 1978 the original 2.5" 3/8" pitch chain was swapped for a 2" 1/2" pitch chain. It was less likely to skip teeth when the chain stretched. It also provided a horsepower rating increase around 19% at 1200rpm and 22% at 3000 rpm.

Interestingly the military humvee t-case uses a similar 1.25" wide chain with a 1/2" pitch. So I guess it would be plausible to say that the NP203 chain is stronger due to the additional width.

BJs offroad
https://bjsoffroad.com/np-203-transfer-case-chain-only-made-in-usa-hv-005/
Has a reproduction 2" or 2.5" chain for sale. This chain has the 3/8" pitch on both widths and will not work with the 1/2" pitch sprockets. I got one about 2 years ago when I rebuilt my 203. It still needs drive shafts among many other things, so I can't speak on its performance.

I researched the 203 before I decided to rebuild it and feel that it's an extremely stout full time unit. Many installed the part time kit not realizing that when in 2wd it doesn't properly lubricate it's components causing damage. I believe the kit suggested shifting into 4wd every so often to sling oil around the case. Also many people assumed it was best to run gear oil instead of straight 30. The chain may not last as long if it's exposed to alot of shock load, although that would be the same for any chain driven case.

Mile marker makes a 509 chain saver kit which allows you to take up any chain slack as it stretches. This eliminates skipping teeth on the sprockets and claims a 3x longer chain life. That would probably make it a lifetime chain if used properly. If anyone has this 509 kit lying around I'll buy it.

How do I determine if I have a part-time kit in my 203? I've had the truck for years but it had locking hubs on it when I bought it. When wanting 4 wheel drive, I've always locked the hubs and then shifted the t-case into either 4-hi or 4-lo. The shifter is always in the middle for normal 2wd usage.

 

[sweetk30]

How do I determine if I have a part-time kit in my 203? I've had the truck for years but it had locking hubs on it when I bought it. When wanting 4 wheel drive, I've always locked the hubs and then shifted the t-case into either 4-hi or 4-lo. The shifter is always in the middle for normal 2wd usage.

in 2wd and hubs un-locked does it drive ? ...... if so then its part-time equipped .

 

[JohnNoble]

Is it advisable to remove the part-time kit and return it to full-time? Do I keep locking hubs? My plan is to use the truck exclusively as a recreational vehicle and not a daily driver.

 

[Chickntrk]

If you can take the case out of LOC and it moves with the hubs unlocked it’s been converted

 

[Chickntrk]

Is it advisable to remove the part-time kit and return it to full-time? Do I keep locking hubs? My plan is to use the truck exclusively as a recreational vehicle and not a daily driver.

Nothing wrong with leaving it, there were two styles one with cogs and a shaft kit. If it’s the shaft it’s fine, the cogs can get sloppy over time but with way it’s a good idea to drive in hi loc every few hundred miles as the chain is splash lubricated and no longer gets oiled in part time.