Dana 20 gear play opinion (video)

[maxellfullmoon]

Hopefully YouTube links are allowed. I posted a video on YouTube of my D20 gear play. If someone could give me an opinion if this is to much play. It seems like a lot to me.
This is off my 73. I had rebuilt it once and not a lot of miles on it since. I'm in the middle of replacing my C4 with an AX15 and now looking at the D20 and want it right before putting it on the new transmission.
Thanks!
Dana 20 video

 

[JB Fab]

Wow, there is something going on with your front output...
Looks like you are missing the spacer.
I would disassemble the entire thing to see what else is going on.

 

[JB Fab]

J-type

 

[maxellfullmoon]

Oh, and I didn't show but there's not any end-play of the front and rear output yokes. They feel just right.

 

[JB Fab]

Oh, and I didn't show but there's not any end-play of the front and rear output yokes. They feel just right.

OK, but the video makes it look like your front output high range gear is moving around.
FYI, some 1972 J-types came with T-type front output shaft assemblies, if the rebuilder was using the J-type diagram the thrust washer and/or SOB C-clip could have been left out.
BTW, "just right" is typically felt with a dial indicator.

 

[maxellfullmoon]

OK, but the video makes it look like your front output high range gear is moving around.

Yes, it is moving around and that can't be right. I'll pull it apart and see. What about the rear output? I don't see any movement in the gears like the front but there is some play. Using my dial gage I get about 0.050" of play. In the shop manual I don't see anything about measuring that kind of play. And I don't know if I'm using these terms correctly. Just wondering if that can be corrected with shims.
I made a video of it. In the video I have my input locked down and it's not moving. Dana 20 dial gage video

 

[Oldtimer]

Your video shows gear lash play, not output shaft end play.
The attached PDF is instructions for Terra Low gear install, but they explain how to "check front output shaft bearing adjustment" on page 3, steps 22 thru 24

 

[JB Fab]

Yes, it is moving around and that can't be right. I'll pull it apart and see. What about the rear output? I don't see any movement in the gears like the front but there is some play. Using my dial gage I get about 0.050" of play. In the shop manual I don't see anything about measuring that kind of play. And I don't know if I'm using these terms correctly. Just wondering if that can be corrected with shims.
I made a video of it. In the video I have my input locked down and it's not moving. Dana 20 dial gage video

The lash you are demonstrating looks completely normal, and is not adjustable.

 

[JB Fab]

Your video shows gear lash play, not output shaft end play.
The attached PDF is instructions for Terra Low gear install, but they explain how to "check front output shaft bearing adjustment" on page 3, steps 22 thru 24

NOTE: The exploded diagram in the Teraflex PDF is of a Jeep CJ type D20 , so the front output would be the same as a '72 up Bronco D20

 

[Viperwolf1]

That main drive gear slop is excessive. That gear is not splined to the shaft. Its purpose is to mesh with the front sliding gear and deliver power through the dogs at the end of it. Those dogs can wear with the excess movement and eventually will lead to problems keeping the front drive engaged. I checked the clearances on a T type front shaft I have on the shelf. It has about .010" play with the proper thrust washer and snap ring installed. I would expect a J type shaft to have similar clearance with it's parts and with the yoke nut properly tightened. You might check the torque on that front yoke. If its loose the shaft can slide toward the rear and create the extra slop you have.