We have an 1986 Hornet III with a Mercruiser TRS outdrive.
After running the boat for the first time this season, we noticed a very small amount of fluid on the outer housing of the transmission. After a closer look, we believe it is fluid being purged from the check valve. The transmission was designed for Dexron II but we are using Dexron III. The boat was serviced in Reno, NV at 4,500 Ft and run in Lake Tahoe, CA which is 6,225 Ft.
We believe the purging of fluid is due to the fact that Dexron III expands more than Dexron II.
Has anyone had this issue before?
Should we be sticking with Dexron II?
If not and we continue with Dexron III, should we be looking to replace the check valve?
Thanks!