• To ALL forum users - As of late I have been getting quite a few private messages with questions about build ups here on the forum, or tech questions about your personal project. While I appreciate the interest, sending me a private message about these topics distracts from, and undermines the purpose of having a forum here. During the day I wear many hats as a small business owner-operator and I work tirelessly to provide the absolute best service possible to you, our valued customer. When I created this forum I rounded up some of the best minds I knew so that any tech question you might have could be asked and answered by either myself or one of my highly experienced moderators, this way the next time this same question is asked the answer can be easily found and utilized by the next IH enthusiast having the same question. This allows me the freedom to run the day to day operations of the business and minimize the impact to shipments and shop activities that these distractions can cause. It is of the up most importance for me to complete the daily tasks in order to best take care of you our customer, all the while providing you a forum to get the level advice and input you have come to expect and deserve from the premier IH shop in the country.

    So with that I ask that anyone with a question about one of our build ups or a general tech question to please use the forum as it was intended. I am absolutely available by telephone to answer your questions as well but at times may direct you back to our website to better field your question or questions. Most other private messages I will be glad to answer for you.

    Thank you for your understanding.

    Jeff Ismail

Dana 20 Breather


Is the Dana 20 breather a press in or screw in? I have another tail that I just tapped the breather out of because it was round at the base, so I just figured it was pressed in. But now looking at it, it has grooves in it like it used to have threads prior to me tapping it out. Unless those are grooves just to hold it in.

I'm getting a lot of oil blowing out. I think it is the breather, but I'm not sure. I thought I'd try plugging something in and running a hose off it to see if that stops this oil slick I got going.


I can't answer your questions about the breather, but I do have some thoughts about the oil spewing. It is most likely the result of failed seals inside your adapter housing allowing atf to migrate into the t-case. Another sign of this is the occasional necessity to top off your trans fluid. Where's that fluid been going? Into your t-case. I'll bet if you pull your t-case fill plug, you'll have an absolute pressurized geyser of cross-mojinated atf and gear lube. I just dealt with this recently.


The d-20 breather is pressed in. The grooves are normal, they assist in holding in the breather in place.

Threading in a 1/8" pipe thread where the breather is, then installing a hose fitting and hose works well, in my experience.

The trans-to-tcase adaptor has a drain hole in it which will allow any leakage to drain. If the hole is plugged, as can happen, then atf could get into the t-case.
Clear the drain hole and see if anything comes out.
The area inside the adaptor should not hold any fluid and is normally dry.


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The case is not over full. I can't even touch any oil through the fill hole. It's leaking, but not refilling.