Transfer case

[HotRodPC]

If it is a true K30, it should have the 205 already unless it has been swapped out.

Correct. If it's a K30 a true 1 ton it should have come OEM with an NP205. So if it doesn't someone swapped it out. Which is common. Guys will buy a 1 ton, rob the Dana 60 and NP205 for another project, put in a 10 bolt front axle and NP208 or 203 and sell it. I've seen a couple peeps get ripped that way.

 

[HotRodPC]

CUCV’s did come with 208’s I believe.

Yep, forgot about that. The only ones that got the NP205 was the ones that needed a PTO added to them and they used the NP205 to do that.

 

[HotRodPC]

np208 arent bad but they arent the best either. since its a 1 ton who cares aboutu the weight and quieter aspects of it?


But iti does have a nicer ratio in 4lo

They're actually tougher than what they credit for though. For sure they have a much better deeper crawl ratio aka Low and are much lighter in weight, so there is advantages. A round pattern NP205 when found probably isn't going to be cheap at all. They are like gold. If you can find a race track pattern with the Turbo 400 adapter with it, it's likely to be much cheaper and it'll work. You'll just have to unbolt your current round adapter and bolt on the race track pattern adapter in it's place.

 

[AuroraGirl]

They're actually tougher than what they credit for though. For sure they have a much better deeper crawl ratio aka Low and are much lighter in weight, so there is advantages. A round pattern NP205 when found probably isn't going to be cheap at all. They are like gold. If you can find a race track pattern with the Turbo 400 adapter with it, it's likely to be much cheaper and it'll work. You'll just have to unbolt your current round adapter and bolt on the race track pattern adapter in it's place.

FIGURE 8? Like the one on my sm465?

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ignore the red circle lol. Or is thre another kind you are talking about?

 

[bucket]

Yes, most CUCV's had the 208.

To replace the 208 with a 205, you would need the round pattern style 205, along with the mounting adapter. Both are expensive. The figure 8 style 205 setup requires a different length output shaft in the th400.

But I believe there are a couple other ways to make it work. Iirc, you can use the long style 205 input shaft from a round pattern case, in the figure 8 style case, to also use the figure 8 style adapter. I'm not 100% positive on that, so more research would be recommended. I believe you can also go about it a couple different ways using high dollar aftermarket conversion parts.

 

[75gmck25]

From what I recall the CUCV’s came in different GVW/load ratings, so they may have used different transfer cases for the HD trucks.

The M1008 (Blazer) definitely had higher gears and you could really tell the difference on the highway. Most of the pickups we used had 4:56 gears because they were shelter carriers. The shelters (like a camper) had radios and other communications gear inside, and the truck also towed a generator trailer with two 5kw generators. We had a few standard pickups that just had troop seats in the bed, so they were probably a lower GVW.

The CUCV with a diesel was a big improvement over the older Dodge M880 pickups. The Dodges had smog-era 318 engines that were really underpowered. If you dropped a tire into a hole in a field or got on too much of a slope, sometimes the Dodges just ran out of power and could not move.

 

[Old Guy Bill]

I’ve got a ‘78 with a TH400 and have been looking for a NP205 to replace a NP203 for quite a while now with no luck….
As previously posted the NP205 came in a several different configurations.
The older “Figure 8” and later “Round” mounting patterns, the adapter between them can be ”Long Foot” (older) or “Short Foot”.
The input type also varied, male and female, also 10, 27, & 32 toothed splines. The input bearing was larger with the 32 spline, and the case will have to be bored to adapt it if it had the smaller bearing.
The driveshaft lengths will be different as also the flange vs yoke styles.
In my opinion it’s not going to be an easy swap.
I located a NP208 which I feel will be much easier to adapt to adapt to my truck.

 

[AuroraGirl]

You must be registered for see images attach

 

[AuroraGirl]

I’ve got a ‘78 with a TH400 and have been looking for a NP205 to replace a NP203 for quite a while now with no luck….
As previously posted the NP205 came in a several different configurations.
The older “Figure 8” and later “Round” mounting patterns, the adapter between them can be ”Long Foot” (older) or “Short Foot”.
The input type also varied, male and female, also 10, 27, & 32 toothed splines. The input bearing was larger with the 32 spline, and the case will have to be bored to adapt it if it had the smaller bearing.
The driveshaft lengths will be different as also the flange vs yoke styles.
In my opinion it’s not going to be an easy swap.
I located a NP208 which I feel will be much easier to adapt to adapt to my truck.

you have a factory th400 and np203 combo and you cant find anyway to get it off your hands?? LOL You realize you have the fever dream ideal setup to a lot of guys out there

 

[Old Guy Bill]

you have a factory th400 and np203 combo and you cant find anyway to get it off your hands?? LOL You realize you have the fever dream ideal setup to a lot of guys out there

Umm, the 203 is not the desired TC, it’s all time 4x4 and the replacement chains aren’t being produced.
You can’t give a 203 away in my area.
Now if it was a 205, then yes it would be great.

 

[AuroraGirl]

Umm, the 203 is not the desired TC, it’s all time 4x4 and the replacement chains aren’t being produced.
You can’t give a 203 away in my area.
Now if it was a 205, then yes it would be great.

NP 203 Transfer Case Chain ONLY Made in USA! HV-005

NP 203 Transfer Case Chain ONLY Made in USA! NP203 chevy chevrolet gm gmc

bjsoffroad.com

 

[nvrenuf]

Yes, most CUCV's had the 208.

To replace the 208 with a 205, you would need the round pattern style 205, along with the mounting adapter. Both are expensive. The figure 8 style 205 setup requires a different length output shaft in the th400.

But I believe there are a couple other ways to make it work. Iirc, you can use the long style 205 input shaft from a round pattern case, in the figure 8 style case, to also use the figure 8 style adapter. I'm not 100% positive on that, so more research would be recommended. I believe you can also go about it a couple different ways using high dollar aftermarket conversion parts.

THIS ^^^^^

The M1008 CUCV pick ups came with a 205 unlike their civilian counterparts. There were some model CUCV's that had 205's but they were special purpose units like the M1028 carriers, etc. (some of these also had Track Lock front L/S diffs).

I’ve got a ‘78 with a TH400 and have been looking for a NP205 to replace a NP203 for quite a while now with no luck….

You will not find a 205 that will directly interchange as the 400/203 uses a unique length transmission tailshaft, it does NOT fit ANY other model tcase.

As a whole the 203 is not a desirable tcase UNLESS a person is building a 203/205 "Doubler" reduction box (see Off Road Design's website) then you need a 32 spline 203 like yours. That said, tech progresses and the Doubler is no longer the preferred reduction box set up but it is one of the cheaper options.

**********

To the OP, if you find and use an '85+ round pattern 205 your driveshafts should be the correct length and the crossmember will not move.

Note: the 208 and 205 do not use the same tcase adapter so get one with the 205, the 208 version does not have a threaded boss for the 205 shifter.

 

[AuroraGirl]

THIS ^^^^^

The M1008 CUCV pick ups came with a 205 unlike their civilian counterparts. There were some model CUCV's that had 205's but they were special purpose units like the M1028 carriers, etc. (some of these also had Track Lock front L/S diffs).




You will not find a 205 that will directly interchange as the 400/203 uses a unique length transmission tailshaft, it does NOT fit ANY other model tcase.

As a whole the 203 is not a desirable tcase UNLESS a person is building a 203/205 "Doubler" reduction box (see Off Road Design's website) then you need a 32 spline 203 like yours. That said, tech progresses and the Doubler is no longer the preferred reduction box set up but it is one of the cheaper options.

**********

To the OP, if you find and use an '85+ round pattern 205 your driveshafts should be the correct length and the crossmember will not move.

Note: the 208 and 205 do not use the same tcase adapter so get one with the 205, the 208 version does not have a threaded boss for the 205 shifter.

also make sure to match the height of the adapter so its not the wrong crossmember/adapter combo

 

[Old Guy Bill]

nvrenuf is exactly correct.
The biggest drawback for the 208 is the slip yoke.
The NP241 with passenger side drop is much more desirable but it’s another unicorn…

 

[AuroraGirl]

nvrenuf is exactly correct.
The biggest drawback for the 208 is the slip yoke.
The NP241 with passenger side drop is much more desirable but it’s another unicorn…

late 205s had slip yokes