Dana 18 , Identification

Can someone help me identify this Dana 18. , Has an unusually long output shaft cap. Large or small hole? Was behind an automatic trans. maybe from an FC-150?

 

Must be a big hole case, the trans still has the transfer case drive gear on the out put shaft. And the pto cover on the transfer case is still intact.

 

It's a large hole, not sure why it has a twin stick front output with single stick shift rods. The rear output is not cast for a parking brake lever.

Also notable that it has Spicer cast into it and not dana.

 

Yeah, kinda odd. looks like it has been in storage a long time from the rust on the output shaft caste nut and thread. the guy who has it said it still had oil in it when he separated it from the automatic recently.

 

industrial part? could be forklift or some such thing...

 

Definitely a big hole case. Looks like an aftermarket adapter to the trans. The puzzler is the output housing on the tcase. I have D18's from a CJ, Willys pickup, and Scout and none look like that.

 

I was thinking it might be a big hole TC. The guy had separated the transmission from it without removing the PTO cover and removing the drive gear. The gear aparanty just slipped thru the hole. He said the drive gear was a 26 tooth. And the mating gear in the TC has 34 teeth. and the intermediate shaft is 3/4 INCH shaft. this makes me think it must be an older model 18 TC. The owner said he had removed the trans and TC from an FC 150. He did not remember the year model of it.

 

I talked to the guy some more and he sad he had removed the trans and tc from a FC-150. But it might not have been a factory set up. ,. Maybe I should ask over on the FC forum?

 

A Turbo 400 automatic is definitely not the factory setup for an FC!

 

I was wondering what the automatic was, thankyou.

 

What are you thinking of doing with it?

 

This is the stock big hole 18 (converted to twin stick) from my 70. It has the 2 shift rails like yours but says Dana instead of Spicer, and has the larger intermediate shaft.


I wonder if yours is actually an early 20 case with 18 guts in it.

 

More specifically, the short, circular bellhousing looks like a nailhead Buick bellhousing. Jeep used the in the late sixties/very early 70s behind the Duantless in the Commando and the Buick 350 in the Wagoneers and J-trucks with an adapter ring to the BOP pattern on the blocks. I have no idea why they used an adapter when BOP Turbo 400s already existed, but that's what they did. Here's a thread that talks about it: TH400 to engine adapter?

Likely the transmission was from a Commando or a Buick 350 powered FSJ. Normally, those would have had Dana 20 transfercases behind them, but the factory adapter would allow a large hole D18 to be bolted on instead.

It looks like a large hole case, so the 3/4" idler shaft and tooth counts don't add up. A large hole case will have a 1 1/4" intermediate shaft and a 29 tooth input gear. It's definitely a mismash of parts.

 

Well, if it turns out to be a big hole it could be used to mate to my T-15. And could become a super 18. However the strange tc has a 3/4 inch intermediate shaft, so I don't think it would make a good candidate for that. If I can find a suitable tc I have my eye on a off set dana 44 flanged rear axle. This way I could run an overdrive in my 74. I could build a super 18 from the dana 20 case already in my jeep but I rather keep it unmolested incase I wanted to change back.

 

Did some of the early dana 20's have a 3/4 intermediate shaft? This case does. So I don't think it would be a good candidate for a 18 rebuild. much rather have one with the 1 1/4 shaft.

 

I'm guessing he measured the intermediate shaft wrong and it's really 1 1/4". It looks the same size as the on in colojeepguy's picture and that one is 1 1/4". A large hole D18 and a D20 are basically the same case, so it would likely work for your plan. The gears may not be of use though.

 

I wondered if he actually measured it or guessed at it. I was thinking the gears probably would need changed because likely the drive gear is something other than a 6 spline anyway, meaning the entire gear set would be different. Plus the tc main rear shaft is an oddball too. So all I would have is a case if I buy it.

 

Agreed. It's good for the case but maybe not much else.

 

You need to investigate the trans/TC better. This appears to be a BOP Turbo 400, but you need to look at the pan shape. A TH400 pan shape resembles the State of Texas.. Also, that is likely an AA or Novak adapter on the back of it, as well as the (assumed) 6 spline shaft the drive gear is on. Also, that is most likely a 29 tooth drive gear.
The transfer case is a D18, likely original from the FC. An FC has parking brakes on the rear drums, not the transfer case. The FC also has a remote linkage to shift both 4WD and Hi/N/Lo with similar linkage to the single-stick on the CJ5. That is not a 3/4” intermediate shaft. Its either a 1-1/8” or 1-1/4”. You need to measure that, and count the teeth on the drive gear to know what this assembly is.
An FC never came from Willys with a TH 400. A lot of things have been modified in the past 60+ years, and this transmission from the FC is one of them.
-Donny

 

Donny, thanks for reply. I kinda wonder just how much he really knows about the transfer case. The listing is about a 2 hour drive one way or I would have just went and looked at it. He said he pulled it out of a FC-150 he had bought to restore. I was having a hard time explaining to him what I was trying to figure out. He did send me a photo of the intermediate shaft/lock plate up close but I was still not convinced it was 3/4, like he said. I ask him if he measured it, he said " looks like a 3/4 to me "was his reply, so not sure if that was an actual caliper measurement. I asked for a tooth count and spline count on the drive gear. His reply was" looks like 26 teeth and the gear on the intermediate shaft gear has 34 teeth". but did not get the spine count. Guess he could not remove the nut and washer to see. I did see on the Novac site that they made an adapter kit for the TH-400 to the dana 18 that included an adapter shaft to convert the th400 shaft to 6 spine drive gears. He wanted 200 dollars for both the trans and the d-18. I was only interested in the d-18 case if it was a big hole and 1 1/4 shaft, don't think the TH-400 would be very valuable to me. The guy has got kinda tired of my questions I guess and has not responded any more. Do you think this could be a small bore TC someone has bored out to a 4 inch big bore to maybe fit the novac adapter? Can you tell from my photo if the 4 inch bore is factory or has been remachined? I am not familiar with them enough myself to be able to tell.That would explain maybe a 3/4 shaft and the 26 tooth drive gear from an older model jeep. I may try to drive up there this weekend if I can get away just to see. Would the Case without the gears be worth the 200 dollars if it happens to be the correct case? Don't know how common they are, a dana 20 case would work just as well and may be eraser to find. Your professional opinion would be appreciated, Thanks Jim