Lower unit oil

[84carlson]

I was looking at my winterization shelf today getting ready for the hibernation and recalled my neighbor sold his bass boat and gave me a box of lower unit oil.  I normally use a Sierra synthetic in my Johnson 115.  I have three unopened quarts, 1 Sierra synthetic, 1 Sierra non synthetic and a Super Tech non synthetic. You think blending the two Sierras would be an issue, I'll use the Super Tech in the Snapper Mower self propelled drive...

Joe

[carlsoncvx18]

I do not think you are suppose to mix synthetic and non synthetic together.

I would not do it.

[V153]

I do not think you are suppose to mix synthetic and non synthetic together

Well, not without express written permission ...  I wouldn't mix the stuff together either.

Please correct me if I'm wrong, but don't they hold just a lil under a qt to begin with?

[84carlson]

Well you probable right on the amount, but when you pump it in it is always hard to get it all out of the one bottle...

[Jerry]

I assume it's not electric shift (that takes type C) I always add STP or JB Gear Lube Supplement to standard ol lower end lube. They're just gears and bearings. Not rocket science.

[David CVX-16]

A few years back Bass and Walleye Boats magazine compared different brands of lower unit greases.

Here is their conclusion after subjecting many brands to different tests:

"After closely studying the data, we noticed one lube consistently tested well, and ranked above average in most of the tests. It also demonstrated good lubricating properties in the water dilution tests. That oil is the Evinrude HPF-XR, highly recommended for the boater who wants it all — good anti-wear characteristics, and no worries about a little water intrusion."

That is what I use in my 115 HP Johnson and of course change every fall of the year. 

[Jerry]

My Johnson is 63 years old, doesn't get changed every year and when I finally resealed it this year the gears and bearings were in great shape. Spend yor money on what you want. I bet they didn't test regular gear lube with STP or JB.

[wiliermdb]

My Johnson is 63 years old, doesn't get changed every year and when I finally resealed it this year the gears and bearings were in great shape. Spend yor money on what you want. I bet they didn't test regular gear lube with STP or JB.

Wow, Jerry!  Do you just enjoy your "Spend your money"  jabs to those who suggest certain products? You can get the Evinrude HPF XR gear lube for $3.99 to $5.99 for a 10 oz. tube. Not exactly breaking the bank. Run you about the same to by two of the three products you suggested. I don't think the major publications are going to test "home brew" gear lubes.

It's just good habit to change the lower unit lube annually. If it runs you $10 then that is less than $1 a month. At least you know what is going on in there every season. Heck, a pack of cigs or 6-pack of beer is nearly the same cost as a lower unit lube change.

[Jerry]

If I get my boat in the water a couple times a year, it was a good year. There's a lot of "preventative maintenance" that prevents nothing, only spends money. I don't  have money to waste. do you think my 63 year old lower unit would be better if I had spent the money to change every year? I do check for water.

[Jason]

IMO. The main reason to change out your gear lube every year is simply to check for water. If don't check it in the fall, and water is in there, then you are looking at a $400 lower unit in the Spring....right Jeff??!!

So at $4 a quart for gear lube, How long does it take to go through 100 quarts of year lube changing it out every year?

[David CVX-16]

I wish I had printed out the Bass and Walleye Magazine article on lower unit grease. The test was very comprehensive, included many different tests, and tested various Mercury, Johnson, Amzoil, Pennzoil, and other well known products. Chances are that any name brand product will last one year. My main concern is water getting into the lower unit during the year and diluting or wearing out the gears because of excess water preventing the lubricant from coating the parts. The Evinrude HPF XR seemed to excel in this area and covered the other areas of concern more than adequately.

Unfortunately it is no longer made, and I had to seach to buy a couple of 32 ounce containers for future use.

A safe bet would to use the most expensive lower unit grease sold by your motor's manufacturer.





    

[Rich_V174SS]

I use Mercury/Quicksilver High Performance Gear Lube in most everything.

[Jerry]

I totally agree. Water is the killer. Mostly for bearings. the reason I pulled my Lower unit and resealed it was I was getting oil spots. and milky oil. But if you crack the lower plug, and all you see is nice clear oil, what you put back in, is no better than what you take out. It's a "peace of mind" thing. If you fell good doing it, do it, but if you just do it because "it's what I do", doesn't mean everybody should do it, or it's the right thing. Living on a Social Security check gives you a whole different outlook.

[wiliermdb]

So, isn't that a perfectly good reason for draining the lower unit fluid at the end of the season so you will know if you possibly have water in there.?

Seems totally justified to spend $10 a year and know there is no water. The 140 I just bought didn't leake a drop. When I went to change the water pump, I drained the fluid and it had water in there. Never would have known if I didn't drain it. The cause was the seals on the driveshaft below the water pump base.

Should have the 140 put together this weekend and then start preparing it for fresh paint.

[David CVX-16]

Running three weeks ago with the Glastron group back from the cove on the Mississippi to Prescott, I had the throttle all the way forward the entire distance trying to catch up with an unnamed fellow Glastron member. I gave it WOT with the peace of mind that my VRO was disconnected and I was running a rich mixture of Premium Plus Mercury oil with BP 93 octane gas, my spark plugs were factory recommended and set at the right gap, the lower unit grease was changed last fall, the pistons decarbonized with Evinrude spray each year, Sea Foam added to the gas periodically, the water impeller changed two years ago, and the propeller allowed the motor to run at an acceptable 5,200 RPM. I need every one of the above items to keep the motor lasting year after year. Cheap insurance. 

[carlsoncvx18]

I know that I will be changing gear lube every fall.  Previous lower had only 3 seasons on it with the oil changed very often, reason chasing a over heating problem, which turned out to be plugged exhaust risers.  Never had a drop of water on the lube changes this spring I did not check the fluid and shelled out a lower unit.

[wexrocks]

I always love this debate... just like the spark plug debate, and the 2-stroke oil debate, and the reed debate... I'll throw my opinion out there, just for fun. I'm on board with Rich, but it's always been my approach. I go with the few extra bucks (literally, a few extra bucks) for the Merc Premium Plus High Performance. Test proven, and recommended by Merc (who knows best? Merc does) for all applications. For good reason. Lubrication, water emulsion, and so on. Here's where I get real stupid... I change it in the fall, and in the spring. It's good for the seals. I also fill it till it comes out the top, then put in the top screw, pump it a few more times to "pack" the gears (like a bearing) and then put the drain plug back in. Not too much pressure to blow seals, but enough to push it in. Feel free to tear that theory apart... It's just what I do.

[Hyperacme]

I change it every fall and also blow another $1.50 on two new fiber drain screw washers ...
Call me crazy, nutz, what ever ...
Like to look at the magnetic drain plug for metal shaving too ...

[CVX Fever]

Used to do it every fall.  Now I run 2-3 seasons. I just drain a little out to check it for contamination.

[David CVX-16]

I also wait for a warm day and let the lower unit grease drain for at least one day.