I have been in search of a good oil for the AX-15. Chrysler now states you can use plain old 10w30 motor oil. As many know, the brass synchros in the AX-15 are subject to damage due to sulfur; the gearing is brass and soft yellow metals. Many folks recommend the MT-90 by Redline. It is on the expensive side.
However, I called Valvoline today, and inquired about their Synpower 75/90 gear lube. Many have wanted to use it, but where concerned because it is GL-5, and that has high levels of sulfur, thus in return, causing gear wear. Well, after speaking with Valvoline they re-assured me, that their oil has an inactive sulfate, that will not cause damage to yellow metals. He said, all their lubes are yellow metal safe.
So, if anyone was wanting to use Synpower such as myself, you can now be assured you will be okay. I have just been using 10w30 motor oil, and it has been okay. I have thought about the MT-90, but may just give this a try as I have been happy with Valvoline products. Hope this may be of some help
Christopher
However, I called Valvoline today, and inquired about their Synpower 75/90 gear lube. Many have wanted to use it, but where concerned because it is GL-5, and that has high levels of sulfur, thus in return, causing gear wear. Well, after speaking with Valvoline they re-assured me, that their oil has an inactive sulfate, that will not cause damage to yellow metals. He said, all their lubes are yellow metal safe.
So, if anyone was wanting to use Synpower such as myself, you can now be assured you will be okay. I have just been using 10w30 motor oil, and it has been okay. I have thought about the MT-90, but may just give this a try as I have been happy with Valvoline products. Hope this may be of some help
Christopher