Why Did M1008s Come with NP208 vs NP205s

[adf5565]

Curiosity has gotten the best of me and figured if anyone would know it would be here, but why do the M1008s come with the NP208 transfer case vs the NP205? Typically everything else lines up with a standard civy K30 (which is inherently what the truck is), however for the biggest difference in the transfer case. Was it just to save cost by using the 1/2-3/4 ton t-case instead? Or did they just want the lower 4-low ratio that the 208 offers? Or something else?

 

[WWRD99]

Curiosity has gotten the best of me and figured if anyone would know it would be here, but why do the M1008s come with the NP208 transfer case vs the NP205? Typically everything else lines up with a standard civy K30 (which is inherently what the truck is), however for the biggest difference in the transfer case. Was it just to save cost by using the 1/2-3/4 ton t-case instead? Or did they just want the lower 4-low ratio that the 208 offers?

My thought on this is they didn't need it. The engine doesn't produce enough power to break one. I think the Gov Lok diff gives out before the tcase.

 

[adf5565]

This is out of the 84/85 civilian truck brochure, even for the 6.2 diesel it shows the NP205 for the K30. I fully agree that the NP208 is more than capable of handling the power the 6.2 puts out but just wondering why they chose to make the M1008s differently.

 

[antennaclimber]

GM took advantage of every cost saving measure they could when building these trucks. A dollar here and there adds up when you are building thousands and thousands of vehicles.

 

[deank]

I believe the answer is the PTO. I Don’t think the NP 208 can accept the PTO. The NP 205 can. PTO was needed to drive the generator in the M1031s.

 

[royalflush55]

Curiosity has gotten the best of me and figured if anyone would know it would be here, but why do the M1008s come with the NP208 transfer case vs the NP205? Typically everything else lines up with a standard civy K30 (which is inherently what the truck is), however for the biggest difference in the transfer case. Was it just to save cost by using the 1/2-3/4 ton t-case instead? Or did they just want the lower 4-low ratio that the 208 offers? Or something else?

I think they wanted the lower 4-low ratio because of the lack of power from the 6.2!! Better for cross country adverse conditions.

 

[deank]

I think they wanted the lower 4-low ratio because of the lack of power from the 6.2!! Better for cross country adverse conditions.

That would be a good explanation also.

 

[biscuitwhistler37]

Weren't 208s gear to gear and 205s chain drive? Sorry if I'm wrong, it's been a while since I played with a "small" T-case .

 

[adf5565]

Weren't 208s gear to gear and 205s chain drive? Sorry if I'm wrong, it's been a while since I played with a "small" T-case .

It's the other way around, 208 is chain while 205 is gear. No problem

 

[cucvrus]

I think they wanted to lower the cost and still have a one ton truck that was capable of carrying out the intended duty. The CUCV was never intended to be a combat vehicle. It filled a time when other purpose built vehicles were being developed. HMMWV as an example. They didn’t even include the support rods on the 208 transfer case that most civilian vehicles had. It was all about the $. Ford had bid on the contract and GM won because of the diesel failure of the 5.7. US Government bailed them out of that multi million dollar fiasco. I changed hundreds of 5.7 diesels from 1979-1980. That was a bad time for the small diesel V 8 engines. Detroit lovers hate the 6.2 diesel engine and swear it is NOT a Detroit engine. But all in all if the CUCV was going to be a true combat vehicle all variants would have had the same drive line including tires and wheels. This set up is a logistical nightmare of parts. Back in the day the Army wanted 1 fuel for 1 Army. Diesel.

 

[CARC686]

You know, I actually had a 1980 C10 with the factory Olds block, but the guts and top end had been swapped for gas stuff from a Delta 88 or something back when it was a utility service vehicle. I guess they figured cutting the compression more than half would stop the heads blowing off. Real oddball. I'd seen it sitting for a decade and one day I went and bought it. Wish I still had it.

 

[biscuitwhistler37]

It's the other way around, 208 is chain while 205 is gear. No problem

Well, backwards as usual lol. That might be a factor, easier cheaper and faster to change a stretched chain than a gear and bearing.

 

[87cr250r]

If you aren't in 4wd every day, the 208 performs better in 4wd, wears out faster, and is cheaper to repair provided you didn't break the case. The case will break when your front driveshaft slip joint seizes up, it's pretty tough otherwise. It may drop into low on you at about 150k miles. It will be a pain to get home but the fork is only $30. Good news is that xfer case is light enough you can remove and install it without a jack. Use anaerobic gasket maker instead of silicone for zero seepage.

 

[WWRD99]

I'm curious about flat towing. Being the 205 is gear drive, not sure if it has an oil pump in it like the 208, would flat towing be the reason?

 

[deank]

No oil pump. Slinger only.

 

[WWRD99]

No oil pump. Slinger only.

Part 5 6 7 is the oil pump.

Sent from my SM-S906U using Tapatalk

 

[deank]

Yup, 208 has a pump. 205 does not.

 

[patracy]

I believe the answer is the PTO. I Don’t think the NP 208 can accept the PTO. The NP 205 can. PTO was needed to drive the generator in the M1031s.

This.

 

[WWRD99]

Yup, 208 has a pump. 205 does not.

Sorry, I was meaning to save that as a draft but hit reply instead!! Was going to say, towing the 208, with the pump on the main shaft, in neutral, it should be able to be towed without taking the driveshafts off and keep lubricated. I think that makes it so the tailshaft of the trans won't spin as well, leave it in park? I've only rebuilt these things but never towed so not sure just using my brain as a parts bin!!

 

[87cr250r]

The NP205 transfer case may not need a pump in the same way that a manual transmission does not need a pump. The chain drive transfer cases operate with a much lower oil level and may not be able to splash lube effectively.