has any one used synthetic transmission oil (4speed trans) ??????? I'm using it, only driven it 60 miles or so, it seems to me I'm hearing transmission noise . Do you think I should switch back or give it a chance? 1965 mustang Thanks Kevin
Is this an old car or new? I seem to remember something about synthetics being a no-no in toploaders.
Synthetic oils tend to be too slippery for the synchros to work properly. If you do use synthetic, make sure it is specifically designed for manual transmissions. Do not use synthetic motor oil. robin
I've used Redline MT-90 (GL-4 spec) in my original 66 T-10 for at least the last 10 years with great results. It is specifically formulated for manual trannys. The GL rating is very important, GL-4 has the right amount of "slipperyness" for manual transmissions. Don't use a GL-5 spec gear oil which is too slick.