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Full-time 4X4

EZ Livin

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EZ Livin Enthusiast

EZ Livin

Posted
Posted

As I mentioned in another thread, it has been over 20 years since I've owned a 4x4. I had a '74 Blazer and a '76 GMC pickup, both of which had the old full-time 4x4 system.

 

As I recall, the transfer case was called "new process" and I think it was built by Mopar for GM and Ford as well as Chrysler.

 

It worked great, but I guess there were fuel consumption issues. Does anyone here have an oldie with this system?

PFarkas Enthusiast

PFarkas

Posted
Posted
As I recall, the transfer case was called "new process" and I think it was built by Mopar for GM and Ford as well as Chrysler.

 

It worked great, but I guess there were fuel consumption issues. Does anyone here have an oldie with this system?

 

 

 

New Process (as in "NP-205") changed their name to "New Venture Gear".

 

They still manufacture transfer cases for GM and Chrysler.

 

They also still manufacture full time 4wd transfer cases.

 

http://www.newventuregear.com/tcases.html

Blue-2001-Z71 Enthusiast

Blue-2001-Z71

Posted
Posted

My 1993 Jeep Grand Cherokee had a full time 4WD system (quadratrac) that seemed to work fairly well, but I think there are too many comprimises. On dry road you probably lose some fuel economy (I got 16 mpg with a 5.2L). Off road it doesn't lock up like a true 4WD would so wheels can slip and spin more since the case and front axle are allowed to differentiate wheel speeds more. I like the new Autotrac setup on my Z-71 as it gives you so many choices for operation.

EZ Livin Enthusiast

EZ Livin

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Posted

Thanks for the link, PF. I gather "Active on-demand" is full time 4WD with an auto lock up, whereas "Progressive on-demand" is an automatic 2WD to 4WD shift?

 

Blue: Both of my old trucks were 350 4bbl's and got about 15 mpg on the highway. I haven't checked the fuel consumption on my '94 yet, need to tune it up first. What's normal for a 5.7 4x4 nowadays?

 

The New Process transfer case had a "lock" mode in high and low range that locked the front and rear driveshafts together, didn't quadratrack?

Blue-2001-Z71 Enthusiast

Blue-2001-Z71

Posted
Posted

Nope, the quardratrac had three settings: 4Hi, Neutral, and 4Lo. Better than say a Rav-4's idea of 4WD but no mud-bogger. Okay, okay, so it was a luxury-oriented SUV but hey, it's supposed to be "trail-rated" right? Some trail. No idea what normal fuel eco would be for you. The last 350 I had was in an '82 Coupe DeVille (13 mpg) with an Edelbrock 4-Bbl and some other goodies. The 5.3L in my truck gets 16-17 driving with a gravity-loving foot. Pretty funny that my 5200 lb 5.3L truck gets the same if not better mileage than my 3600 lb 5.2L Jeep.

Larry Enthusiast

Larry

Posted
Posted
As I mentioned in another thread, it has been over 20 years since I've owned a 4x4. I had a '74 Blazer and a '76 GMC pickup, both of which had the old full-time 4x4 system.

 

As I recall, the transfer case was called "new process" and I think it was built by Mopar for GM and Ford as well as Chrysler.

 

It worked great, but I guess there were fuel consumption issues. Does anyone here have an oldie with this system?

 

 

 

 

EZ Liven,

 

The transfercase you are talking about was the NP203. It was a very heavy cast iron piece….even heavier than the NP205 and about twice the physical size. To my knowledge GM, Ford and Chrysler all discontinued it after 1978 or 1979. It was not the same as quadratrac found in Jeeps…similar but not. The NP203 had Hi, HiLoc, LowLoc, and Neutral. When the lever was in the “loc” position the tranfercase split power 50/50 to the front and rear axles. In “Hi” it split power somewhere near 60/40.

 

Most of the 203’s have been converted to part time with the Mile Marker part time kit. I ditched my TH350/NP203 all together for a SM465 4 speed manual and NP205 on my 78’. I was partial about ditching the auto trans but for the wheeling I do in the high country a stick shift is a must.

 

The 203 made a good boat anchor just like the NV246 AutoCrap transfercase of today. :devil:

EZ Livin Enthusiast

EZ Livin

Posted
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Posted

Larry:

 

You seem pretty knowledgeable about 4WD systems, can you suggest some places where I can find out more technical details about the different systems? I have to admit that right now I actually know very little about my own truck (I just bought it last week). About all I know is that there is a lever and indicator light on the floor, and it apparently has automatic locking hubs. There seems to be quite a delay between moving the lever and when the light comes on, but I gather this is normal.

 

I haven't even had the transfer case in low range yet. (the owner's manual says the truck should be rolling slowly in neutral to do this :flag::smash::D )

 

Do you have any tips / comments you can share about this system?

 

Thanks! :devil:

Larry Enthusiast

Larry

Posted
Posted
Larry:

 

You seem pretty knowledgeable about 4WD systems, can you suggest some places where I can find out more technical details about the different systems? I have to admit that right now I actually know very little about my own truck (I just bought it last week). About all I know is that there is a lever and indicator light on the floor, and it apparently has automatic locking hubs. There seems to be quite a delay between moving the lever and when the light comes on, but I gather this is normal.

 

I haven't even had the transfer case in low range yet. (the owner's manual says the truck should be rolling slowly in neutral to do this  :flag:  :smash:  :D )

 

Do you have any tips / comments you can share about this system?

 

Thanks! :devil:

 

 

 

 

EZ Liven,

 

There really isn’t anything on the web that I know of to learn more about different systems other than a real nice piece on the front axle disconnect system at the Posi-Lok website.

 

Your 94 is very straightforward. Pull the lever and go….no wires, no encoder motors, and no control heads to fail, etc. The only bad thing about 88-95 trucks is the front axle disconnect used the thermo actuator. When the lever is pulled a detent switch is closed in the transfercase allowing current to be sent to the front axle disconnect. The early disconnects like yours were called thermo actuators and had a solid material inside that turned into a gas as it heated up allowing the fork to be moved in the front axle to engage. Just a complex way of getting away from manual locking hubs. Some crazy U of M grad must have stayed up all night engineering that contraption.

 

The delay for the 4x4 light coming on is due to the length of time it takes the thermo actuator to heat up. That was normal for them.

 

You can either retrofit the electric axle disconnect with a kit from any GM dealer or the best way is using the Posi-Lok kit. It is a fully manual system just like manual hubs but from the cab. It will also allow you to have 2wd Low, which can be nice for backing up trailers and such.

 

 

Check them out……..Posi-Lok

EZ Livin Enthusiast

EZ Livin

Posted
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Posted

Larry,

 

Thanks for the info and link. :devil:

 

I think I'll drive it the way it is this winter and see whether the existing system is adequate or annoying enough to warrant changing.

 

:smash:

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