D18 Companion Flange Nut Size

Can someone tell me the size of the nut on the companion coupler shaft on the D18? Dimension and TPI

 

3/4-20 and it takes a 1 1/16 socket to remove. (if it's the same as the yoke nut.)

 

I think mine uses a 1 3/16 socket. Were there 2 different sizes?

 

Yes 2 different output thread sizes depending on era or vintage.
Early transfer cases used castellated nuts while later used same hug lock type of nut that the axle pinions use.
TC output shafts could easily be interchanged between early 2.43 and later 2.46 ratio D18's.

 

I have the hug lock. Does anyone know the nut size? Mine has been torqued at least a couple times and I don't want to run in to a problem. Was just going to get a new one.

 

Maybe this is obvious, but I would just measure it. Digital calipers are cheap at Harbor Freigth. Take the battery out after use.

 

If it's the old style of hug lock then I re-use those all the time with zero problems.
Can you post a pic of it ?

 

I'll be taking it off this afternoon. Was just hoping to go get a new one before I got all greasy if I knew the size

 

Yes, there are several ways to check threads, including using the 3 gage pin and micrometer method. I thought one of the more experienced guys might already know the size. thanks

 

The castillated nut should be 1 3/16". Thats the one that uses a cotter pin to lock it. I believe they were used at least through the mid-1960s. That style nut can be reused indefinitely.
-Donny

 

One of my posts over on the 2A forum covers this.
Here's the very first part of that thread.

DANA MODEL 18 TRANSFER CASE PROGRESSION

Like all Jeep components the famous Dana model 18 (D18) underwent a continuous progression of changes.
The very first transfer case changes occurred before mass production of the MB/GPW.
Bantam was concerned with where to place the transfer case outputs in relation to the axle carriers..
The early Bantam BRC transfer cases had LH outputs and LH differential carriers

In 1945 the intermediate shaft diameter was changed from 3/4" to 1-1/8" for increased strength and durability.
Also the early military ratio of 1.97 to 1 was changed to 2.43 to 1 for all 1945 and later Jeeps.
The 2.43 ratio D18 was used from 1945-1954-1/2.
It is a very good transfer case and it's plenty strong behind any Willys engine.
These Brown / Lipe units remained basically unchanged through CJ2A and CJ3A production.
In 1953 both front and rear output shafts and their associated nuts were changed.
A "Hug Lock" nut replaced the previous "Castlelated" nut.
The Hug Lock nuts have less thread pitch and they also interchange with those on the axle pinions..
Shaft changes and A-980 vs 801367 nuts:

As the 1953 3B came into production the safety wiring of bearing cap bolts was done away with.

 

That's great info Ken. As always, I really appreciate your help.

 

Sorry with the info above. I didn't read the question correctlty. I thought you were asking about the nut on the back of the transmission shaft retaining the main driven gear under the PTO/OD cover.
-Donny

 

Never a problem Donny. Happy Jeeping. Still hoping to see pics of yours and the Tux. Loving mine. Actually got it running well.

 

Donny that was almost right.
Both the castillated and the hug locks were also used on various BW transmission main shafts.

But then as they say "almost" only counts with horse shoes and hand grenades !

 

Ok I got to ask, where did you hear about using a micrometer and the 3 wire method to measure thread size? Any machinist is going to measure with a thread pitch gage and micrometer. The 3 wire method is for measuring to cut a thread to exacting standards not measuring the thread pitch and size.

 

From the machinist view, you are correct. I worked for many years as an Engineer in both automotive a d aerospace, much of it in the quality role. Yes, pitch gage for crown, deaddendum, adddndum, minor diameter, etc..., and micrometers are sometimes for major diameters and are indeed the accepted method of checking threads. From the quality side,the three wire method was an old method to check the machinist's work. But Mcruff, you are correct.

 

Nukes too