Dana 20 - Front Output Thrust washer/spacer

[Amitchla]

Hi guys,

I’ve been working on tearing down my Dana 20 to figure out the root of a nasty vibration I have. My Dana 20 is a ‘73, and has a Teralow gear set.

In doing so, I’ve found that the current washer/spacer had pressed itself onto the shaft, past where the c-clip was supposed to be (which was not installed), so I had to cut it off. Also, the front bearing was the complete wrong size.

Does anyone have a link to where I can buy a new one of these? I found this, but it’s for a Jeep Dana 20, and I’m not sure if our application is the same.

https://4x4.fatbobsgarage.com/mobile/washer-front-output-dana-20-p19473.aspx

Thanks!

 

[mrdrnac]

I have a J shift front output shaft with the two washers included in the parts for sale section. That will show you what the J shift assembly looks like at least.

 

[mrdrnac]

Sounds like you have a T style front output shaft, you can use a J style shaft to replace it and then you don't use the snap ring. Also the 2 shafts T and J use different size bearings, other than that they are interchangeable. 73 was the year the switch from T style to J happened.

 

[Amitchla]

Thanks @mrdrnac! Is there an easy way to tell the difference between the two?

I can tell you - the front bearing that was installed is a Timken 14131, and it’s inner diameter is easily 1/4” too big for the shaft.

 

[Viperwolf1]

Here are some good D20 notes. The D20 went from T style to J style rails in '73. Low gear ratio was changed slightly at that time. Prior to the rail change there was a change to the J type front output shaft.

Seals:
Input shaft seal (double lip)-CR #517383,Napa #NOS 18676, CR #18676 (good seal) (Do not use Timken #473179)
Output shaft seals-Timken #450185
Shift rail seals-CR #6204, Timken #471466
Yoke o-ring-1-1/4"OD x 1-1/8"ID x 1/16". Danco happened to be the brand at the hardware store and it is their #29.
Speedi-sleeve for yokes-SKF99155

Bearings:
Input- SKF #307NRJ
Rear output-Timken #25877 (inner), Timken #15117 (outer)
Front output, J shift-Timken #14116
Front output, T shift-Timken #14131

Cups:
Rear output-Timken #25821 (inner), Timken #15245 (outer)
Front output-Timken #14276 (both T and J)

Shims: 1.20" ID, 1.50" OD

Yoke nuts: 3/4", 16 tpi, top lock


When setting the rear output endplay use a Timken #15118 in the rear position. It is the same size as the #15117 except the inner bore is a couple thousandths larger. This allows you to assemble and disassemble the output shaft without needing a press. Only use it as a setup bearing. Once the correct endplay is set, drop in the #15117 bearing, put the seal on and assemble the shaft.

 

[mrdrnac]

The ID on the J Shift bearing #14116 is 1.19"
The ID on the T shift bearing #14131 is 1.3125"

Sounds like you have a T Shift bearing on the newer J Style shaft, .1225 too big of ID. And that would make for one heck of a vibration!

 

[mrdrnac]

The T Shift Shaft is on the top of the picture, it has a slightly larger diameter where the output bearing rides, and it has a grove for the snap ring used on the T Shift shaft.

 

[Amitchla]

Thanks guys!

@viperwolf1 - thanks for the specs! I’m constantly referencing your “Dana 20 Tricks” thread also. Great info!

@mrdrnac - that confirms it. Whoever rebuilt this case used an incorrect bearing on the front of the front output shaft. I hadn’t been considering the front output shaft as the problem, as the vibration disappears when in FWD, but perhaps the difference in engagement of the front output between RWD and FWD only allowed the bearing to vibrate when not under direct load?

There was also a spacer left out on the input gear as well, so the problem is likely from multiple sources at this point - BUT this is a huge discovery for me.

Thanks again!

 

[Amitchla]

Would either of you know the dimensions for the washer/spacer between the drive gear on the bearing on the Front Output on the J-Shift case? As mentioned - all I can find online is the link above to the Jeep washer.

 

[mrdrnac]

I would measure the ones I have for sale and get you the numbers, but the parts are stored 160 miles away from where I'm at now and I wouldn't be able to do it for some time.

https://classicbroncos.com/forums/showthread.php?t=307778

 

[Viperwolf1]

Would either of you know the dimensions for the washer/spacer between the drive gear on the bearing on the Front Output on the J-Shift case? As mentioned - all I can find online is the link above to the Jeep washer.

I do. It is a precision ground (very flat on both sides) washer. .176" thick, 1.193" inside diameter, 1.800" outside diameter. Probably hardened to some extent.

There is also a second spacer that goes just under the yoke on a J shaft. It's .200" thick, 1.130" inside diameter, 1.440" outside diameter.

 

[nvrstuk]

Old guy story...

So I was just lucky rebuilding and swapping parts on my Bronco tailgate from a T-case that I had just peeled the teeth off the cluster gear on Poisen Spider and was swapping all those parts into the '74 case that we had brought to Moab as a spare for my buddy. I had no idea at the time that so many of those parts weren't interchangeable. lol

I remember not realizing in the dark that the frt input shaft on the T style had the C clip. After using my bottle jack with a chain and a couple bolts as a press on my tailgate I remember looking more closely with the flashlight and seeing the C clip. Nobody that evening around the campfire had thought of that... Oh Well... it all worked great for a couple years and it got me around Moab for the rest of my first trip there 20+ years ago.

 

[Amitchla]

@mrdrnac - thank you! Since I already have the output shaft I’d prefer to find just the washer, but I’ll keep this as a backup option in case.

@viperwolf1 - thanks for the thorough info! I’m in process of trying to find something that matches this now. I’ve asked Jack O’Brien if 4 Wheels West to see if he has any.

@nvrstuk - ha! Great story. Honestly this one must have run for a couple thousand miles (somehow) before developing problems. They’re beefy little things!

 

[nvrstuk]

These guys will fix ya up with everything you need.

Great resource here!

Hope you get it up and going soon!