• 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

T-19 Gear Box question


re: Gear Oils rated at GL-5 not as good as GL-4 or GL-3 due to "yellow metals" corrosion.

Help me understand the yellow metal corrosion issue. If I use GL-5 gear oil, does the corrosion take time (how long, how many miles)? and I am having trouble finding GL-4 or 3 where I live. NAPA? or where else? In So Cal, in Los Angeles County.

Thanks for the replies.


You want GL-1 also known as Ford Tractor Oil/mineral oil for your T-19 and your D20 T-case. That oil is plentiful and easy to find nearly everywhere. Save the GL-5 for your differentials.

DF Sales&Marketing

Oil Tech Moderator
The subject of GL-1 & GL-5 Gear Oils has been covered many times already, but for those who have missed it, GL-1 (which is obsolete) now GL-4 do not contain EP additives and do not provide the anti-wear and temperature protection as do the GL-5 Gear Oils.

BUT, keep in mind that ALL SWEPCO Gear Oils which are rated to meet GL-5 DO NOT have the yellow metal compatibility problem and can be used in any application calling for GL-1 & GL-5. You can use the SWEPCO 210 Gear Oil in Diffs, Manual Tranny and TF cases which call for gear oil whether it is for GL-1 or GL-5.

The SWEPCO 210 is available from IHPA in gallons, and recently they have also purchased it in cases of quarts....either size are available from the LUBRICANTS section.

Hope this clears up any confusion regarding gear oil, if not, I can go into more detail if needed.