26 or 29 tooth Dana Transfer Case??

Is there a way I can tell if my Dana 18 Transfer Case is a 6 spline 29 tooth with out tearing it apart? I bought a Saturn OD and it is the 6 spline 29 tooth and was wondering if it will fit. Looked on the Herm Site and nothing was said about this just showed 2 types the 26 and the 29 tooth. I would think my Dana 18 was made in 1962(62 CJ5 Willys) but who knows? Just would be nice to know befor tring to put it in! Any help on this? Mark

 

You can measure the diameter of the intermediate shaft.
A 1 1/8" intermediate shaft has a 26 tooth gear on it.
A 1 1/4" intermediate shaft has a 29 tooth gear on it.

But the best thing to do is take 5 bolts holding the PTO cover off and count the teeth. The cover is below the oil line, so you dont have to worry about any fluid spilling out.

If you have a T90 trans (as a '62 should as it originally came with a 4 cylinder) then it will be 6 splines.
If it is a factory equiped V6 model, then you should have 10 splines.
But again, the best thing to do is to pull that cover off and look.

 

That is to easy! I thought you would have to pull the planitary section out or something. So you can see the gear with the cover off. I will take a look today. Sure hope it fits or I will have to sell it! Mark

 

The level was real close but it did not leak out sitting level. I guess I scored it is a 29 tooth so it will fit! I only need a $48.00 shifter lever to shift it and the lock washer and special snap ring that I beleive keeps the planitary cluster from getting loose on the shaft out of the Transfer Case it threads onto. I saw them on the Herns Site so I can just order those. The Saturn part list shows them as costing around $7.50 so not to bad. The OD looks pretty new inside no wear on the gears I can see and inside my transfer case it looks nice also no wear I can see thru the cover plate hole. Looks like a easy instalation just need to bolt it in right so the press fit neadle bearing does not bind when bolting it up. This one is the Advanced Adapters re/make of the Saturn Over Drive. Mark

 

Mark, check out the gear chart on the Novak web site - it really shows the different gears for the different d18's. Just kinda cool to see.

If you do take that back cover off take a minute to check out the condition of the teeth on the intermediate gear. This is how I found the broken gear teeth on mine.

Does anybody know what the oil level should be relative the the back cover? The oil fill hole on my d18 is nearly impossible to get to so I just fill through the back cover but not sure how full to fill it.

 

Since I had just serviced mine when I removed the cover it was about 1/4" below the cover hole bottom. My gears looked nice when I was just in there from what I could see thru the hole. Mark

 

V6 models with a T86 tranny (until somewhere in the '68 model year) also have a 6 spline. But again, the best thing to do is to pull the cover off and look

My 1968 V6 had a T86 and I was able to use the 6 spline warn OD from my '65.

 

Wow, I've never heard about a 26 tooth gear on a 1 1/4" shaft.

Just drives home the fact that the only 100 percent certain way is to open it up and count.

 

Today I have been working on a Warn overdrive I recently acquired. It has a 29 tooth gear on it, and for a six spline shaft (T90). I have been doing some research on which transfer cases have a 29 tooth gear, and found this old thread with some information I found interesting. I know the thread is 17 years old, but since I found it interesting and useful I thought others might benefit.

From what I have been told, and what I have found in researching this, the D18 with the larger 1 1/4" intermediate shaft usually has the 29 tooth gear, but as mister "Warloch" pointed out above there are variations which have that shaft and a 26 tooth gear.

I found out today from Keith Buckley (Joe Friday on the CJ2A forum) that the oddball large shaft 26 tooth D18 was used in the the M series military Jeeps. Keith has been very helpful to me with my first dive into an overdrive. With his guidance I was able to disassemble the unit and was very pleased with the condition of the internals. Everything is in good shape, it was just glued together by sticky old dried up gear oil.

So while this overdrive should fit a CJ5 standard, it would not work on a M38A1.

 

I’ve had an M38-A1 that had a 29 tooth main drive. I have another original T90/D18 from an A1 in the garage that I’ve never opened up. When I get home next week, I’ll check to see what that has in it.
-Donny

 

I've swapped 26 tooth gear sets in 1 1/4" intermediate small and large input hole cases lots of times for customers. Mostly because their gears were good and they had an overdrive. No modifications needed so always check to see what you have.

 

The downside of installing the 26 tooth set in a 29 tooth case is you just made it weaker. When you look at the spur gear teeth, the 29 tooth version has significantly more beef.

 

I’m well aware of that and have tried to explain that to the customers. When they still insist because they have an overdrive I’ll do it if they sign the paperwork saying they understand it is a down grade. I also don’t warranty breakage and that goes on the paperwork as well.

 

One other thing I should mention that I didn’t originally. Lots of the customers already had 26 tooth transfer cases with overdrives and simply needed a large input hole transfer case. The benefit was also the larger 1 1/4” intermediate shaft and more needle roller bearings to distribute the load better. Strength of the gears didn’t change but there are other benefits like better load distribution on the intermediate gear and shaft due to more bearings, stronger case, etc., etc.