Loadstar T36 Transmission Oil

I have a 1973 Loadstar with the 345 engine and T36 Five speed transmission. I need to install a PTO on the side of the transmission so I'm going to have to change the oil at the same time. What is the best oil to use for this particular transmission? Also can you add too much? I've heard of installing an elbow on the side of the fill level hole to add an additional 2 pints or so. Is this recommended or will the extra oil cause more harm than good? The truck only has 33,000 original miles so it runs like brand new and I would like to keep it that way!

hi,

I recall reading too the use of an elbow was recommended for a small additional quantity of a pint or so of oil - something about something not getting enough lubrication in extended slow-speed operation. I remember it made enough impression on me that I intended to add an elbow to my 5 speed trans.

As to what type of oil, if I recall the T34, T35 and T36 were not critical as long as it works for a manual transmission. Some oils are very detrimental to the yellow metals in a manual transmission. Hopefully someone with more experience than me jumps in with the best trans oil to use. But any mineral oil, or engine oil will work ok from my understanding in a T34 - T36. But I think if you want the best of the best, try this:
http://www.ihpartsamerica.com/store/SWE ... 210-G.html
It may be overkill, but if you want the best ... its also supposed to be very compatible with the yellow metals in a manual transmission. This company has been making specialty oils and lubricants since 1933, many aimed at the old IH market, especially their engine oils for reasons too numerous to type tonight.

After the T34, T35 and T36 series, for a short 2 years IH used the T434, T435 and T436 trans. After that, beginning roughly in 1973 - 1974 IH began using the T494, T495 and T496 series until sometime in the 80's they switched to the T696, T698 and T699 series. All series look identical on the outside, however internally parts will not interchange. I have no idea how to tell the difference without disassembling them. But I mention them for the benefit of others. As I recall reading one of the differences is the use of needle roller bearings in the reverse circuit. And this necessitated the use of a special oil different (thinner?) from what's used in the T34-T36 trans series. So if you have one of these transmissions, all I can suggest is to check your owners manual.

My .02, hope it helped.