Dana 18 hot

So after only 160 miles on a fresh "rebuild" my Dana 18 t-case gets pretty warm. Like, I can't hold my hand on it... So obviously somethings up. I drop the pan and find play in the intermediate gear, it will slide front to back. I didn't use new bearings in the rebuild I just put small hole stuff and big hole stuff together in a big hole case. I also have an overdrive on a new Muncie 420 from novak. I'm not too sure if my overdrive is lined up correctly with the intermediate gear. It looks like it is a little to far back and trying to twist the intermediate gear into the washers and therefore creating the play. I'm fairly sure this is the issue, any ideas how to correct? I've tightened that overdrive onto the shaft as tight as it will go, and I don't think I can pull the overdrive any closer to the tranny. The heat is built up after going a constant 60 mph for most of the miles. Did I just break this in wrong? It looks correct and I even measured the tail shaft end play and shimed it to get it correct. Any thoughts or suggestions? I think my first method of troubleshooting is going to be ordering up a rebuild kit and replace all the bearings and that important shaft even though it looked good before. It would be nice if someone had some pictures of the overdrive in the case and how their gears lined up. Thanks!

Drew

 

If you can move your OD, you've done something wrong.

You shouldn't necessarily tighten "As tight as it will go." Check Herm's write-up on his OD page.

Do you have any pics of your installation? Novak isn't infallible.

The spacer that goes around the output shaft determines OD depth:


Here's the pic of the OD in the D18:


This was the result of my OD working itself back a couple thousanths, probably due to not being torqued down correctly:

 

The actual movement or slop is in the intermediate gear. From what you described it sounds like I have the wrong spacing in between the overdrive and the tranny. I'm definitely going to have to get a hold of herm. Does anybody have pictures through the pan of the gears meshing? I will be able to get some pictures this coming weekend for more detail. Thanks!

 

Post up some pics.

Don't have a pic with the OD installed, but not much else to see other than they mesh up as positioned below: