Trim pump oil?

[OneFineFiftyNine]

I'm posting this to clear up some confusion created by a coworker. I have a 1970 Larson 185 with a Mercruiser 120 I/O. It has that square body trim/tilt pump, but honestly I don't know much more about it.

On the pump it says to use only 20W oil in the system. My coworker says you can use 20W-50 motor oil in there and it will work just fine. I'm really not sure if this is a good idea, but I am definitely no hydraulic expert.

I ask because I am having problems with the tilt/trim system. (my one good trim cylinder extends, but doesn't retract. I only have one good trim cylinder, the other has been removed and the lines capped off for diagnostic purposes) I was wondering if using the 20W-50 would cause any additional problems than what I am already having.

Thanks again for your patience with a beginner!

 

[tommays]

Re: Trim pump oil?

If it is taged 20 wt just stick with that why add any thing to your problems

they have used all kinds of oil over the years even ATF


Tommays

 

[180shabah]

Re: Trim pump oil?

If you can't find straight 20 weight oil, the 20W50 will be fine. Your trim pump will never heat it up enough for it to behave like anything oher than 20 weight.