Yet another T-Cases to mount to the V8 Thread

[V8BoatBuilder]

That dude's "writeup" was an interesting read. Here's what I gathered he had to do to the Jeep 208 to make it work with our trucks.
1) Swap the input shaft
2) Swap the tailhousing and the speedo drive
3) Fashion a 1" spacer to go between the trans tailshaft housing and the front of the case.

Not too hard: would just mean buying a ford 208 and a Jeep 208, and getting creative. T-cases aren't that hard to rebuilt, and this would be a killer time to do it.

The fixed yokes on either side would make driveshaft adaptations a snap.

 

[Nitrous SSC]

Didn't get the measurements last night but will be getting them tonight. Doing a tranny and x-fer case flush. His fluid looked like burnt OIL!

 

[V8BoatBuilder]

Did some digging on the np208:
Originally found on:
http://www.high-impact.net/transmission_and_gear/Tcase_np208.htm

Low Range reduction ratio: 2.6 to 1
High Range: Direct 1:1

Chevy, Dodge and Ford all used variations of this transfer case. All were chain drive to the front output, with a light weight aluminum case. Most used a slip-yoke rear output. We are not aware of a Fixed yoke conversion for this case. While these units will hold up under moderately heavy off road use, they are not considered the preferred swap due to the chain drive and thin aluminum case.

Bolt Pattern:
6 bolt circular pattern. Note: This pattern is almost symmetrical, however it is not and will only bolt up one way. Chevy, Dodge and Ford all used the same bolt pattern, However with a different ROTATION of the pattern. Dodge and ford are close, and swaps might result in a useable Tcase droop angle, however Chevy units are about 90 degrees different and cannot be interchanged. Ford units have a driver side drop, While GM units are passenger side drop.

Chevy 208
Passenger side drop (front driveshaft). This Tcase has the GM rotation of the 6 bolt circular bolt pattern.
Input Spline: We have run into two different input spline configurations on these cases.
-27 spline: The units supplied with a T350 or 700R4 automatic have a 27 spline female input shaft.
-32 spline: This is the preferred shaft, as it is the strongest. These came behind Turbo 400 or SM465 transmissions.

Ford NP208 Transfer Case
The Ford NP208 has a 31 spline female input. The bolt pattern is the Ford rotation of the 6 bolt circular bolt pattern.

Dodge NP208 Transfer Case
The Dodge 203 has a 23 spline female input. It uses the same front bolt pattern as the Chevy unit.

Edit: From my limited research, the Jeep and Dodge versions have the same 23spline input, and 6 bolt patter. This is why the case works with the back of the 4R70W or AOD.

 

[V8BoatBuilder]

The NP208 was used in:

1980-1988 Jeep J-Trucks/Cherokee SJ/Wagoneer SJ/Grand Wagoneer SJ
1980-1990 Chevy K-10/K-20
1980-1986 Ford Bronco/F-150/F-250/F-350
1980-1982 Dodge W100/W150/W250/W350

I will add to this list as I know more

 

[Nitrous SSC]

mmmm 2.6:1 *drool*

Dumb question. I did read the links. Is this a manual t-case or electric?

 

[V8BoatBuilder]

mmmm 2.6:1 *drool*

Dumb question. I did read the links. Is this a manual t-case or electric?

2.61.... Oh man I can just think about that. It's better than the BW cases, which have a 2.4 ratio.

As far as I know, the NP208 is an all-manual case, with an inline shift pattern (2hi-4hi-N-4lo). We'd have to get the linkage off the old truck, and adapt it to fit ours with some clever bracketry and a hole in the floor. There are lots of shifters out there from the different vehicles, in both auto and manual trans versions. Ideally, it would pop up next to the console.

 

[Nitrous SSC]

Doing a custom shifter would be an ideal situation to convince the wife I need a welder

I could totally handle a shifter next to the console that looks clean. It would definatly be alot easier to install without alot of wiring.

 

[Nitrous SSC]

Ok I looked at my friends F150's T-case last night and I don't see anyway in hell it would fit. The one in my X looks like a tonka toy compared to that F-150 one.

 

[V8BoatBuilder]

Ok I looked at my friends F150's T-case last night and I don't see anyway in hell it would fit. The one in my X looks like a tonka toy compared to that F-150 one.

Get the measurements anyway?

The t-case in my dad's V6 Isuzu Trooper is a beast, ours are so little.

 

[V8BoatBuilder]

Photos of the NP208

Did some searching, found some photos of a NP208 Ford.

Found this on ebay, its a clocking ring for the NP208. 5/16" thick...

Here is the t-case, showing the linkage and tranny adapter. We'd be using the tranny adapter on our 4R70Ws.

 

[V8BoatBuilder]

Warform, can you take one of those pics and circle what you had to cut off from the case please?

 

[Fusion213]

I'll pick up the case tomorrow and get some pics for you guys WITH a tape measure!

 

[V8BoatBuilder]

Excellent news in the Linkage dept.

I was changing my O2s today, and inorder to do so, the center console has to come out and the plate in the floor below has to come out to reach the connectors. This plate is also directly above the transmission tailshaft housing.

If you look in the photos of the Ford NP208 posted above, the shift linkage attaches to the tailshaft housing (the aluminum that goes from 4 to six bolts). Well our tailshaft housing, on the 4R70W, has two threaded bosses on the driver's side! Not only is the location perfect for the shifter coming up through the plate/next to the console, but the stock linkage may just bolt to our Tailshaft housing, no mods!!

I took some photos, more to follow.

 

[Nitrous SSC]

So basicly all we'd need to worry about is how to support the case via crossmember and the driveshaft lengths? That would sure be cheaper than doing a manual BW T-case with an AA adapter.

That definatly made my day reading that

 

[V8BoatBuilder]

So basicly all we'd need to worry about is how to support the case via crossmember and the driveshaft lengths? That would sure be cheaper than doing a manual BW T-case with an AA adapter.

That definatly made my day reading that

Glad it made your day - made mine!

You can cross another thing off your to-do list, which is supporting the t-case. These lightweight aluminum cases, such as our current BW4404, the BW135x, and NP208 don't attach to any crossmember or the frame, merely the transmission tailshaft housing. However, the crossmember may be an issue because our front driveshaft has a rather small "window" it needs to pass through, above the crossmember.

We will have to worry about driveshaft lengths and yokes, unless we can rig something up from the junkyard.

I'm not sure about clocking as of yet..... Warform?

 

[Heath]

What do you mean by clocking??? I'm curious how we could do the speedo, is that what you mean by clocking???

The guys with 98+ don't have to worry about it, their speedo comes off the rearend, the 96-97 guys it comes off the T-Case...

 

[V8BoatBuilder]

What do you mean by clocking??? I'm curious how we could do the speedo, is that what you mean by clocking???

The guys with 98+ don't have to worry about it, their speedo comes off the rearend, the 96-97 guys it comes off the T-Case...

By "clocking" I mean the drop angle of the transfercase. The clocking is usually set by the oreintation of the bolt holes on the tailshaft adapter, and then on the t-case itself. Obviosuly, the driveshaft is independant, as its the axis the t-case "rotates" upon.

Clocking is very important in our case because the front driveshaft yoke needs to be pointed directly above the crossmember. If there is too much drop, the yoke will be pointing directly at the crossmember. Too little drop, and the t-case will hit the cab floor.

There are adapters, similar to wheel spaces that can change the clocking of a t-case. However, then tailshaft length becomes and issue.

The speedo shouldn't be a problem for anyone if my research is good. Fords have always had the speedo drive in the tailshaft of the t-case, and our VSS has the same gear as an old school cable drive. I could be wrong here though.

 

[Heath]

Thanks for the education.. And lets hope that your intel is good...

 

[V8BoatBuilder]

I'm going to try and pick up an NP208. Or at least get my hands on one to measure it, photo it, yada yada. Thats the next step: junkyard diving.

 

[Nitrous SSC]

I wish I wasn't so busy with work or I'd try to get one.

What is it looking like price wise?