I would watch out using motor oil in a tranny. If your tranny calls for 50 wt tranny oil yea but nig difference between tranny oil and motor oil.
Many late model transmissions call for 50 weight motor oil, usually in a full synthetic. The NV4500 is an exellent example of this, it not only specifies 50 weight synthetic motor oil, but also a specific brand (Castrol) which is fully noted with part numbers on the PTO cover on the right hand side of the transmission case. Use of anything else will destroy that transmission.
It should also b noted that many modern manual transmissions use ATF3 (Dexron3/Mercon2) as the factory fill.
