Transfer Case ID?

Can you ID this transfer Case?


http://postimage.org/gallery/180l5j4fc/

 

Centered output. I'll guess a twin sticked Dana 20.

I'm sure someone more knowledgeable will chime in.

What is the diameter of the transmission bore? 4 inches?

 

Yep, should be a 20. It has the press fit shift rail caps on there and it is the 20/big hole 18 case. Can use that case to build a "super" 18.

 

Yup, Scout Dana 20

 

How do you know it's a Scout?

Because it's twin-sticked?

 

Nope, cause of the front output housing the shifters are attached to. Definite Scout. About 2 or 3 years of Scouts did use factory twin sticks on the 20, but there are so many kits out nowadays you can't just go by that.

 

Yep, nickmil you are the man!!! I knew you would know what it was, I was told once on this site that I could not build a Dana 20 to look like a stock twin sticked D18 and function like a D20. I wanted my Jeep to keep the look of a stock CJ3A, so the case, shift rails and shift tower are Scout D20, terra low 3.15 gears, and a D20 reardrum emergency brake setup. What is so neat about these old Jeeps and Scouts, is that you can make up just about anything with stock parts. So, is that a kool transfer case or what? PS, I really like D20 transfer cases, as they are so quiet when running with the Top on and are less maintenance with only the rear output spinning when in 2 wheel drive (rebuilds last longer) and I don't mind centered rear ends. So, nickmil, what are your thoughts on a off set D44 to the drivers side to get rid of the compound angles of the drive shaft (rear output in line with pinon)? This is my view on the subject, your views may have different milage.

 

Nothing wrong with off setting the pumpkin to the drivers side so the pinion is centered. I suspect the reason Jeep offset the pinion to the passenger side was so the axle shafts were the same length, i.e. only have to stock one rear axle shaft. It's not a lot of offset and would require a custom housing and shafts is the biggest down side.

 

The D 20 was specifically designed and termed as the "silent type" transfer case (circa 1962)
Dana's 1st attempt to design a quieter transfer case ended up as the 1954 D 18 having 2.46 reduction, 1-1/4 intermediate and finer gear teeth.


The D 20's an excellent unit but its certainly not very desireable for off-road use having only 2.03 reduction.
Twin stick controls, Terra low gears and the parking brake are exceptionally nice additions.

As you mentioned the front to rear differential carrier alignment becomes a technical driving issue.
However I feel that the increased rear propeller shaft angle is a bigger concern.
For this reason the offset D-18 wins hands down for off road use due to the lower rear output.

Probably the greatest issue is that you are now restricted from installing an O.D.
That fact is both good and bad.
It is good because you have one less assembly that can possibly fail.
It is bad because the Warn O.D. essentially turns a meager 3 speed into a practicle close ratio 5 speed.
Essentially a 4 speed O.D. (1st gear and OD is generally not used)
Realize that some transmissions and the Warn O.D. are better than others due to their specific ratios.

Because the D 20 without O.D. cannot split gears one should only consider mating it to a V-6 or V-8.
This is simply because these produce more torque than most all of the I-4 engines.

In my opinion the optimum transmission mated to the D 20 is the T18 or the Ford T19.
In practice most all of the truck type 4 speeds operate using only the top 3 gears.
Low is simply geared to slow for street useage. So you essentially only have 3 gears for the road.
1st, 2nd and 3rd. Low gear is generally not used.

You also must consider the ideal final drive ratio for use with a D 20.
I will vote for 31" tall tires and 4.27 final drive (CJ option from 1972 through 1975)
Or perhaps 4.09 final drive (mid 1960's PU truck or SW ratios ).

If I had that unit I would build it like...
D-225 / T18 / D20 with 3.15 Terra Low /4.27 centered flanged D44 with Powr Lok / D30 Powr Lok / Power Saginaw upon a 3A or 3B body and frame.

Very nice and very interesting ... keep us posted !

 

What I am building has a Chevy inline four, which I sold to build a 3.0 inline four, already mated a Ford T18 (used steel bellhousing to make adapter), running Jeepster centered D44 (4.27 ratio) with a D30 front. Both with Powerlocks, I have a set of D44,s cut down for later use if I decide to go that route. I mainly posted this item to show that there all kinds of options that can be built with original jeep or scout parts. Also, it has been slow on this site for awhile, so thought I would see who was awake! Since I have been around jeeps and dueing conversions for 41 years I know somewhat what parts are out there to due what I want. I also did not want to run an over-drive, I am going to run 33's so it should go down the road OK, and with the T18 and Terra low gears it should be great off road. So, Happy 4 wheeling!!!

 

Its obvious to me that you know what your doing.
Just ignore my repeated information.
I just tend to add extra information so that others can follow the concepts.

So you ditched the 153 for a 181 ?
I will assume that the fuel efficiency should be very good for either engine with that drivetrain combination.
I have a desire and most of the parts to build a similar jeep.
But I keep leaning the big hole D18 @ 2.46 or maybe Terra Low
Terra Low as in low bank account ($$$)

Had you considered a GM 153 stroked out to a 169 cu inch using the 181 crank.
That should yeild about 9.4 comp ratio.

 

Howdy, As, I said I posted this for fun to see if anyone could identify my transfer case, as I wanted a twin stick D20 made from stock parts. As, for the Chevy engines, in my original Jeep I had a an early model Chevy 153 that I had blue printed and ran real well. But, as I added power steering the early block did not have the mounting holes to mount a chevy 250 six power steering pump bracket. So, I got a late model Postal Jeep motor that was a true rear sump motor with the mounting holes I needed. But, in the mean time I found a very clean OMC long block in 3.0, so decided to go that way for the extra cubic inches to run the power steering. I had three motors here, but have since sold my original motor to finance my next motor, and when I am through with my build I will sell my Postal Jeep 153 motor which is a rear sump motor, which is the one you need in a Jeep. You need the rear sump motor to clear the front Pumkin. I have had V6's before, but in this CJ3A, the Chevy Inline fours fit so nice and I like all the room in the engine compartment. Back to my transfer case, I paid the money and bought the Terra low kit, as this may be my last Jeep Build as I over 60 years old and need to start driving things and not being tied up building stuff. I like talking Jeeps, so happy four wheeling.

 

That's a PRIMO transfer case alrighty... but I tend to get caught up in the system as a whole.
A component assembly is only as good as the complete system allows.
And yes "quiet" is certainly a good thing. Less noise infers less internal friction.

Yet I still feel that the D 225 may be a better match for the Scout D20
This is due to the general limitation having 3 practicle transmission gear ratios for on road useage.
The added torque from large displacement will compensate for less gearing potential.

That said the OMC 181 is probably my next favorite choice to power a D20.
181 cubic inches is huge for a modern design 4 cylinder engine.
And honestly I think fewer moving parts is better than more.
Plus its a better balanced design than the odd fire 225.
As you know a 181 must be adapted for automotive use meaning the manifolds, oil pan orientation etc.

Like you say the postal 153 is the absolute best fit under the 3A hood.
I just talked to a guy a couple days ago with a 1969 Postal 153 engine for sale.
I would really like to play around with one of those puppies.
I have several F-134's and a couple of D-225's but Im a sucker for the middle position.
So much so that I'm contemplating a postal 153 stroked with the 181 crank.
Yeilds about 170 cubic inches.
I'm concerned with obtaining optimum CJ fuel efficiency.

Anyway what type and size of clutch / flywheel do you plan mated to the 181 ?

I don't imagine that a 181 with a big clutch and 6.32 T18 could ever break that D20.

 

Here is what I am going to do with my Chevy 181, which happens to be a OMC boat motor which has a centered oil pan pickup which should clear my front pumpkin, seems these motors came with three positions for the oil pickup, front, center and rear sump.

I am going to use the 153 head so I can use stock automotive manifolds. I have been talking to the inline guys that work on Chevy six’s and I am going to put in bigger valves, and some lump port inserts to improve the 153 head, and I will run an Isky RV cam and have the crank, rods and flywheel totally balanced. I am using and old steel ANSEN blow proof bell housing that I had for years as it was easy to grind off the Chevy bolt pattern and drill the Ford pattern and just weld in some taped plates for the bolts (worked great). I am going to use a stock 153 tooth Chevy flywheel and clutch parts.

I also got some of those cool mercruiser aluminum valve covers and side lifter inspection covers! I have run a Chevy 153 motor that I built up with an Isky cam and being balanced that provided enough power for me. So, I think this new 3.0/181 motor should be even better! Seems like we went from D20 ID, to Chevy Inline four information, Oh well that’s what sharing information is all about.

 

Vhunter,
I am running the Mercruiser 3.0/181 engine in my 2A. The 3.0 cyl head is far better than the 2.5/153 version in stock form. Valve and port sizes are considerably larger, and you already own them.
How I managed to use the automotive intake/exhaust manifolds was to fabricate an adapter from 5/8" x 2.5" steel flat bar and sandwich it between the manifold gaskets from each engine. The studs that attach the manifolds are in the same location on each engine and after those holes were drilled in the adapter, it was a simple matter of scribing the ports from the gaskets on both sides of the bar stock and cutting that material out with your favorite method of metal removal. Then its a lot of die grinding.

Food for thought.

Otto

 

Thanks for your advice, but I do not have a 3.0 (eight port head). All I have is the siamise port 153, but I talked to the guys that make the lump ports the chevy six. They said to just use the lump ports and put the bigger valves in the 153 head. Then it should breath just as good, as I do not want to buy another head and then make a conversion like you suggested. So, what else have you done to your motor, what Cam, and what carburator are you using? Thanks,

 

I bought the engine from a boat salvage yard. It was pulled from a 70s vintage Seaswirl, 16' if I recall. The engine is still in stock form.

I'm running the automotive style intake/exhaust manifolds and the GM Monojet carb that came with them. The first engine I purchased for the jeep was a 2.5/153 that I found on Craigslist. It was partially disassembled but complete; the only reason I bought it was to get the manifolds and the rear sump oil pan. It was some sort of boat application also.

Otto