First, pics of the input shaft end play, nearly 1/4" possibly even 5/16" of play.





And to the less important stuff.

Planets are identical...



And the problem:



On the left you have the input shaft bearing and the input shaft from the manual transmission. On the right, the set from the automatic transmission model. I put the manual input shaft into the case containing the automatic input shaft bearing. Now you can see how it was able to "walk" forward. The bearings are interchangeable, so I put the correct bearing in there.

Now we have another possible problem here:



Not sure what you call those, but they go into the input shaft, the back end of it. You can see the gear on the left is from the manual trans model t-case, the one on the right is from the auto trans model t-case. The input shaft behind them is from the auto trans t-case, notice the gear cutting on the input and the matching shaft? Well, the gear on the left matches the next pic, which is the manual trans's input shaft I already re-set into the planet gears, they are otherwise identical in height and whatnot.



So, it's outside curing in the sun for a few hours to let the gasket material set up before I put it back in the truck. There is no end play and it went together much tighter than last time. So, if your going to attempt this, take the bearing with the input shaft....and the gear directly behind the input shaft so it matches. The tailshaft matches, and the rest of the re-build was fine from the first time, but I'm glad I did not ruin anything by driving around on it as hard as I did.

 

Range shift hub.

 

Yeah, that thing! Thanks.

 

Here. Steal this. I know you are done already but save it somewhere, then you will have it

Yes it's for a 231.

 

bump for a very useful thread denoting the difference b/t same NP231D tcase that sits behind auto or manual.

Both have same spline count, however, shaft length differs.

Manual tranny -- tcase snout is longer and different bearing.

Auto tranny -- tcase snout is short stubby.

You can swap just as the OP did here.

 

Good point!

I had an extra NP231D that I sold a while back, the buyer had me measure the shaft for him. He had an auto and I think the first t-case he bought was from a manual since the shaft was a different length.

 

Yeah, met with a guy last night to buy my tcase (from auto). I was explaining all the seals to him and asked for the heck of it what tranny. When he said NV3500, I was like....uhhh different spline count and length. Told him I'm not selling this to you unless for sure. He unfortunately drove an hour too. :/