I have a 3spd trans with manual OD. What fluid should I be using, or does it matter. Put that mineral oil from tractor supply in it but it leaks on the floor. Can I use standard weight gear oil say 90w? Heard some say yes others no. Thanks
This HAMB thread should answer your question, even though not your trans specifically, it still applies. I found this out about the new generation gear lubes, the formulation is not good for the br*** components that are found in most older manual transmissions.When I went to freshen up the lube in my Muncie, I did some research and discovered that not only should you not use the new GL-5 grade lubes, the old (correct) GL-4 had become somewhat hard to find. Ended up finding NAPA carried it in Sta-Lube GL-4. Link http://www.jalopyjournal.com/forum/threads/saginaw-4-speed-lube.958785/
The other thing you'll find is many (if not all) of the currently available gear oils are multigrade (75W-90, 80W-90, etc) and older transmissions will tend to leak with the thinner modern lube oils, even with new seals. Try to find a oil with the first number (the one with the 'W' after it) as close as possible to the original recommended weight.
It should also be noted that the OD trans have two fill/drain plugs, one for main trans and one for the OD. Oil does flow between them, but filling just one won't fill the other...
Been using Sta-Lube GL-4 for 20 years in my synchro-mesh 3 speeds. It doesn't peel the yellow metals parts off, like GL-5 does. Find it at your local Napa store or Amazon and other places... http://www.amazon.com/Sta-Lube-SL24239-GL-4-Multi-Purpose-Hypoid/dp/B000M8RYMC Note: Sta-Lube uses now black containers instead of the white ones they had for years. Still the same oil, just black package now and a little harder to find in the shelves, when you look for the familiar white ones.
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