Dana 18 , Identification

Here is the photo of the shaft and lock plate he sent me. If the lock plate bolt is a 1/2 inch then surely the shaft is bigger than 3/4. Sure does lookk crusty!

 

It was very common to bore out early 18 cases to the 4" hole so don't get wrapped up there. An fc front bearing cap is easy to spot as the inboard side was machined down to fit on a t98. Lots of less than accurate info in this thread guys.

 

I've done this myself, in a futile attempt to mate a small hole 18 to a T15.

 

Sounds like you're just looking for a large hole transfer case? I'd pass on this thing if it's a 4 hour round trip. You can use a Dana 20 case as well.

 

The easiest thing to determine if this is a big hole D18 is to simply measure the hole; 4” for a big hole, and 3-1/8” for the small hole. All factory big hole cases will have a 1-1/4” intermediate shaft, though some ‘65 small hole cases can have the 1-1/4” shaft. No 3/4” or 1-1/8” shaft cases were big hole, unless they were bored out. Though not real common, small hole cases were bored out to 4” for custom conversions, which this yellow example may be.
$200 sounds like a lot (to me) for just a case.
-Donny

 

Yeah, 200 sounds a bit high, especially with lots of D-20 cases around. I bet there is a lot of gear sets for D-18's around too, where Terra low gear sets have been installed if I searched. Thanks for your reply.

 

My 2 cents: I have never observed the pressed on shift rail caps on a small index case. And all FC cases were 1 1/4" shafts with the 29 tooth gear set. The 57 FC cases, at least the FC 150 version, does have the parking brake drum and is no different than the CJ small index version, front bearing cap included.

The D20 case that I used for the 3.15 gear set in my 3B was a $15 item at the local scrap yard------

 

Now that you mention this, I must agree. It looks like in his TC photo to have pressed on caps. The guy did send me an up close and clear photo of the drive gear and it did have 26 teeth! The mystery deepens. Someone may have installed the wrong drive gear, If the pressure angle of the teeth matched it might have worked to some extent, there might of been a little excessive backlash between the gears though with the 26 tooth being a little bit smaller than a 29 tooth.. Like every one says, 200 dollars is quite high anyway, I can likely find a D-20 case locally and much cheaper, no rush anyway.

 

Small hole (bottom) vs large hole (top) cases-



Note how much more cast iron is across the top of the big hole case. Also the 2 shift rails as mentioned above.

 

The 26 tooth gear set works fine in all D18's except the 3/4" shaft MB/GPW cases. You just need to swap the complete set. That said, there is no advantage to replacing the 29 tooth set and, in fact, a few demerits. That 2.43:1 set spur gears are significantly less stouut than the 2.46:1 set-no doubt the primary reason Dana changed those.

 

Thanks for the great comparison

 

This is not a BOP Turbo 400. The bellhousing in the photo is round:


A BOP bellhousing has two very prominent ears:


With the left side starter, it's probably Buick Nailhead. Both Jeep and Rolls Royce used those with adapters to mount to their engines of choice. AMC had a round bellhousing Turbo 400 but the starter bump is on the other side.

It's definitely a large hole case. You can see the casting sticking up over the hole in the picture:

 

Well, I stand corrected, there is a valley at the top of the BOP bellhousing. I’ll have to check my AMC TH400 under the bench tomorrow to see if its the same as the picture, though I think the starter is on the passenger side.
The 26 tooth gear really has me puzzled, TerraLow gear set? I don’t know how you could used a Brown & Lipe early gear set with a larger intermediate shaft. What else used a 26 tooth gear?
Did Kaiser-era J Trucks use a TH400, or just Wagoneers? These vehicles used only D20s?
It would be interesting to see what this yellow mystery combination actually is.
-Donny

 

Good eye spotting that!

 

A little more follow-up on the TH400 automatic pictured in this thread. I think I have the exact unit under my bench, same bellhousing shape and driver’s side starter. I don’t know what output shaft this one has, but mine is 32 spline. The bellhousing pattern is GM Buick and Olds from the 60’s, what Fireball calls “Buick Nailhead”. Kaiser and AMC Jeep used an iron adapter ring to use this with both 6 cyl (in-line and V6?) and V8s. There should be an aluminum ID tag on the right side of the main case that at least will give the year, in the one I have, “72” for 1972. I know mine came out of a ‘72 Commando, and had a D20 behind it. I’m missing the adapter between the trans and D20.
I also have a TH400/Quadratrac behind an AMC 360, all out of a ‘74 J 2000, in another vehicle. Its interesting that this TH400 has a different bellhousing shape (square blocks at each bolt hole) that directly bolts to the AMC engine, and the starter is on the passenger side. The output shaft is a unique 15 spline that only fits the Quadratrac for my 1974 (‘73 thru ‘79) application.
I have answered my question regarding the 26 tooth drive gear. Thats the most common drive gear used in D20s, as opposed to 29 tooth drive gears commonly used in the D18. Both the D18 and D20 have exceptions to the common tooth counts.
Maybe this info will help someone else out there.
-Donny

 

Yes, I did find this out too. the dana 20's gear set had a 26 tooth drive gear set. the ratio is 2.03 or so, rather than the 26 tooth gear that was in the early D18 with the 2.43 ratio set. The gears are not interchangeable, they have differnt pressure angles.

 

This is getting to be an interesting thread, I may drive over there just to see this trans and TC, even if I don't buy it. It would be worth the trip just to make some pictures up close. He want's 200 for both units and wants to sell them together. Any of you guys interested in the TH 400 for a few dollars? I might buy it if the TC has a 1 1/4 inch intermediate shaft.

 

There are two different gears for the stock Jeep turbo 400 adapter. Both of them are 26 tooth. So you can run any 26 tooth transfer case behind them as long as you have the correct one for your case 17.5 or 20 degrees. The Novak info sheet can answer all your questions. This is simply a Jeep turbo 400 1966 to 1972ish with an 18 behind it. There were three different adapter rings that Jeep used to bolt this case to different motors as well as an AMC case that didnt use an adapter. The 18 is a soup salad of different parts.