Mobil synthetic 75/90 gear oil
 

Any one using mobil systhetic 75/90 gear oil in there outdrives? Goood, bad, or indifferent.
Mine is a 2004 XR and is in need of an oil change.
Thanks

I run it in my Kaama drives, with no problems at all.

Thanks Cuda, how often do you change

great stuff. period.

I use it in a Bravo, works good.

Anyone use it in a TRS?

I ran it in a overpowered Alpha 1 for around 5 years with no problems. The gears looked great every season after teardown. I changed it every 25-30 hrs. This summer I had a leaky seal and water entered the drive. I noticed the gear oil resevoir off color and pulled the boat and replaced the seals and cleaned everything. Gears looked ok. Put it back together and the next change I noticed alot of metal on the magnet. Tearing down the drive revealed the F and pinion gear teeth were coming apart.

Did the Mobil 1 being diluted with water cause this? Would Merc HP Syn have prevented this? It's up in the air but I am switching back to Merc Syn just b/c of this as it supposedly protects better if water enters the drive.

Always ran the Merc stuff. Changed to Royal Purple 70/90. Probably similiar to Mobil. I plan on changing every 30 hrs.

I would be reluctant to use anything thats not designed to tolerate water. If it has emulsifiers and the like it will say so.

The Amsoil Marine Lube is set up for that. I've been using it for two seasons...so far so good....It's a little "thin" though...