Rebuilding the Dana 20 Transfer Case

[Lumpy Grits]

YUP-That can be even worst.....
I'm very lucky in that my neighbor and friend, has been my primary UPS deliverery guy for the last 22yrs.
LG

 

[Hedgehog]

Oh my, Christmas in July! I originally stayed home to collect my wayward UPS package. But delivery people were here all day with shipping labels from "Summit Racing", "NOVAK", "Advanced Adaptors", "JB Conversions", "Terra Flex". One thing is for sure, there won't be many original parts left in the old Dana 20 Transfer Case .

 

[Lumpy Grits]

Merry Xmas!
LG

 

[Hedgehog]

CJ, Tarry99, Busadave and yes even you Lumpy thanks. The Dana 20 is in pieces. A relatively easy tear down. The only problem popped up when removing the Allen set screws holding the shift forks on the shaft. The set screw deep in the case and tight. Had to get a 3/16" Allen socket t crack those open. Now for a good case cleaning.

 

[Lumpy Grits]

"Endeavor to persevere"
LG

 

[Hedgehog]

My buddy Bill helped with the tear down so we went out for breakfast and came back to a Transfer Case and parts that were to hot to touch. Tonight I'll clean the cases up and start the rebuild. At this point the finished product is definitely in view.

This drives me nuts, maybe because I'm a draftsman and know how hard we worked to make sure that all the parts callout names were the same as what is referenced in the tear down/build text. I see text references to cage and roller for instance, I believe that is a modern tapered bearing, but in the schematic there is NO cage and bearing. There are many other names in the text that don't match the schematic. This sort of thing simply drives me nuts.

 

[BusaDave9]

This drives me nuts, maybe because I'm a draftsman and know how hard we worked to make sure that all the parts callout names were the same as what is referenced in the tear down/build text. I see text references to cage and roller for instance, I believe that is a modern tapered bearing, but in the schematic there is NO cage and bearing. There are many other names in the text that don't match the schematic. This sort of thing simply drives me nuts.

Me too.
The text should always match the drawings but so often they don't. Many, if not most, manuals talk about one part and the pictures never label such a part. Then you realize that the picture has a different name for the part.

 

[Hedgehog]

Exactly Errrrrrr.

Busa - Did you have to grind your case? I guess some of the newer cases, which I have, don't need to be ground. Naturally I'll be checking no matter what, I'm just wondering is all.

 

[Lumpy Grits]

To add, that when you go to the parts house or order the part. It's now under another name/title.
LG

 

[BusaDave9]

Exactly Errrrrrr.

Busa - Did you have to grind your case? I guess some of the newer cases, which I have, don't need to be ground. Naturally I'll be checking no matter what, I'm just wondering is all.

Yes I did. I had to grind quite a bit but not enough to worry about the strength of the case. It's pretty obvious how much and where to grind. Just keep trying to install the gears until you have enough metal removed.

 

[Hedgehog]

Lumpy - I think this is what you are asking.

Low gears - Ordered from Advanced Adaptors, Member price = $945, quite a bit less than everybody else wanted. They drop shipped from TerraFlex, they are real deal Terra Low gears (china). The kit comes with all seals, a mid shaft and gaskets. Maybe not though. After asking Advanced added a gasket set to the order. A quick check says, possible rip off, but probably not, they care about their reputation in a fairly small community.

Bearings - Supplied by Advance Adaptors, ~$100, the bearings are not American manufacture. They are manufactured by KOYO in Japan. Not so bad, they could be Chinese.

Hey Busa - How did you remove your pill covers. Haven't tried to work on them yet. They could be drilled, but none of the kits have replacement covers. I'd like to remove then undamaged if possible.

Also, exactly who designed those aluminum poppet screw on covers? The stock ones were in place, but there was no removing those soft sobs. Rob says that a fine thread 1/2" screw will do the trick nicely. After a little measuring it will, seems like a very bad design to me.

 

[Lumpy Grits]

KOYO bearings are excellent bearings, and make many with the Timken name on'en. Have no worries about them!
You got a very good deal on the gears!
LG

 

[Hedgehog]

Don't you hate it? The 20 is in pieces and my inventory of broken parts consists of only 5 parts. I should have been prepared for 4 of them. Those 4 are the two ball bearings and poppet springs on the shift rods. The other is a bit of a shocker. There are a couple shims on the rear output shaft. One is rather thick, the other is very thin. The thin shim is essentially shattered one piece is about 2/3 rds of the complete shim. The rest consists of little more than chunks.

A lesson learned. If you are contemplating rebuilding your T-18 and it's Transfer Case along with all the bearings, seals, and gaskets get replacement coil springs and poppet ball bearings for every one you can find. In my case I think there was one ball bearing that wasn't scared beyond use and the springs were rusted, or collapsed, or shattered in some way. Here I am ready to rebuild and the very first part needs the shift fork spring and ball bearing. .... STOP!!!! .... Wait until Monday. Darn it!

 

[Lumpy Grits]

Will the shims from your R&P work, fit?
LG

 

[Hedgehog]

I've got to see if I still have any of them around. Rob gave me his bag-o-shims to take what I needed. The shims not used went back to Rob. I don't know if you guys have one of the new BIG ACE's. They have an amazing selection of odd things. They actually might have the springs and ball bearings I need.

 

[Lumpy Grits]

Wish we did have a 'Big Ace' here.
I have to drive about 20 miles to a small mom-n-pop h'ware store that has an outstanding bolt/nut section.
LG

 

[mtnwhlr]

Probably way more nuts when your there

 

[Lumpy Grits]

Probably way more nuts when your there

A lot of loose screws too...

LG

 

[BusaDave9]

Hey Busa - How did you remove your pill covers. Haven't tried to work on them yet. They could be drilled, but none of the kits have replacement covers. I'd like to remove then undamaged if possible.

I can't answer that.
My Dana 20 came out of a full sized Jeep. It did not have the pills to prevent me from cross shifting. That mechanism was built into the shift housing (U shift pattern)

My Dana 20 was similar to this one but I have a T-18
After removing the shift rails the shift detent balls come out the 2 holes on the top of the Dana 20

 

[Hedgehog]

That shifter is kinda cool.

The covers ended up being drilled. The hole is small enough to be spot welded without ruining the covers. Since the springs need replacing, I'll stop at Willys Works to see if he has the covers, springs and shims. I might just tap the holes and put set screws in the holes. The top poppet holes will need something similar.