270 Oil Question

"I have an oil leak in the upp

"I have an oil leak in the upper gear housing and am getting ready to replace the o-rings and oil seal. But my question is this, what kind of sterndrive lubricant does a Volvo 270 outdrive use? I ask because the leaking oil sure smells like 90 weight gearcase oil.

On marinemechanic.com I found the following statement "270/280/290 Volvo sterndrives DO NOT always use 30 w engine oil for lubricant." So now I am concerned.

Did the VP 270 ever use 90 weight gearcase oil as a lubricant?

I last had it serviced at a marine shop before moving in 2004, with little use since. If someone did put 90W gearcase oil in there would it have caused any damage? What effect would it have? If I drain it to change the oil seal and then refill it with 10W30 will that now cause any damage?

Any help will be appreciated."

According to V/P the 270 requi

According to V/P the 270 requires straight 30w and not a multi viscosity. The change back to the correct oil should not cause any problems as there are not reciprocating parts in the drive and it is not pressure oiled.

"You may continue to use EP90

"You may continue to use EP90 oil or change back to 'engine oil' as was the original min recomendation. The EP90 oil has a better ability to absorb humidity and may carry heavier 'load' on the gears. If You change lower unit to duoprop, Volvo recomends their synthethic EP90 (GL5) oil. The original recomendation was more of convenience to the customers, only one type of oil in engine and drive. What is important is that You do not use an oil that 'foams' as that may cause overpressure and blow seals. The oil temp in upper unit may go above 100C at full load!"