What fluids/oils should I be using?

Y

YN2(SS)

Petty Officer 2nd Class
Joined
May 10, 2009
Messages
137
1989 Mercruiser 5.0 LX 4bbl with Alpha 1 outdrive.

PO was using Mercruiser 25W40 oil for the engine and, I'm sure this will lead to a discussion, automotive power steering fluid, for the trim system.

What are the correct fluids for:
Engine oil
Lower unit
Trim system

I live in Illinois, freshwater use only, if that makes a difference.

Thanks!
 
wellcraft-classic210

wellcraft-classic210

Master Chief Petty Officer
Joined
Sep 22, 2010
Messages
839
Re: What fluids/oils should I be using?

THIS IS A SUBJECT THAT WILL MOST LIKELY VERY PER OWNER.

Here is what i do.

Castrol GTX for motor oil. 30w or 20 /50 w is preffered over thinner oils. Its getting harder to find the thicker oil. I seem to recall Mecrc reccomending straight 40w & some posts on this site saying its OK to go thinner. ( change oil before winter storage! )

Mercruiser brand oil in the outdrive & per the instructions don't mix it with other brands. I am buying the better oil here as I want good protection should water get in my oil ( Again ). I have seen milky Sierra oil protect a drive. Do not use Automotive grade lubes here as thay do not offer water intrusion protective additives. ( change oil before winter storage !)


I have not had to add or change trim fluid but understand 20w motor oil is OK to use. (I may try changing it this year & will watch this post for reccomendations )

I am using Green grease for almost all the grease points on the trailer & out drive. The Merc brands have specific additives and are probaly better but I grease annually at a minimum ( more on exposed zerk fittings ) & run low hours compared to many.
 
H

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Re: What fluids/oils should I be using?

Howdy,


Either have a look at a Mercruiser owners manual or go to Mercruisers website http://www.mercurymarine.com/servic...nd-maintenance/faqs/mercruiser/?category=fuel so you can consider what Mercury suggests what you "should" do.

Otherwise you'll get a different:
Here is what i do.
Click to expand...
from everyone that posts an answer.

You can also search this forum and get literally HUNDREDS of "Here is what i do's"


So far, all of "them" have worked successfully.


Cheers,


Rick
 
M

MarkSee

Lieutenant Junior Grade
Joined
Sep 10, 2010
Messages
1,172
Y

YN2(SS)

Petty Officer 2nd Class
Joined
May 10, 2009
Messages
137
Re: What fluids/oils should I be using?

I appreciate all the responses.

According to my SELOC manual,

QUICKSILVER Formula 4 4 cycle SE40 oil and NEVER use multiviscosity oils. Mercruiser (link above) recommends Mercruiser Synthetic 20W40, or if not available, 25W40.

Automotive ATF for the Power Steering (SELOC).

QUICKSILVER Super-Duty lubricant for the Stern drive (SELOC).

QUICKSILVER Formula 4 4 cycle SE40 for the trim pump (SELOC).

I think its pretty clear I need to drain and flush the power steering fluid from the trim system.

Again, THanks all!!
 
Don S

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: What fluids/oils should I be using?

DO NOT go by what Seloc says. They are just an aftermarket manual and give all kinds of bad advise and information.
You don't want 40W in a trim pump, nor do you want Super-Duty (whatever that is) gear lube.

Gear lube should be Mercruiser Hi-Performance gear lube.

Trim/Tilt and Power Steering, use Quicksilver Power Trim and Steering Fluid. OR, and this is from the service manual

IMPORTANT: SAE 10W-30 or 10W-40 engine oil
can be used in system, if Quicksilver Power Trim
and Steering Fluid is not available.



HOWEVER, being is it's an older boat, look at the trim fluid and power steering. If it's red, it's ATF, which means someone changed it a long time ago.
 
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