Gear lube, Marine verses Auto versions

Status
Not open for further replies.
I was always a big fan of Merc fluids, more so the gear lube, gimbal bearing grease etc. Even the corrosion guard spray.
After decades of boating and doing my own service on a number of boats I owned, I still remember just a few years back, for the first time ever, I used a different gear lube, I got cheap, still called a marine gear lube, I bought it in the marine section maybe it was Pennzoil?
I forgot, anyway I knew the moment was began pumping it in and the way it ran out that is wasnt the same as the Merc lube. I also noticed how easy it was to clean off my hands, the darn Merc stuff is impossible to get off easy like the other stuff.
I did this part of my prewinter service, it stuck in my mind and I changed back to Merc during the boating season, Knowing it was different I couldnt go the whole boating season, to me it was a waste of money for the Pennzoil (yellow container)
Merc advertises their lube is "tacky" in case of water intrusion it will better protect. I am now a believer. Simply because i have experienced it first hand. THe Merc is very tacky, the other brand was not. Does any of it matter? It mattered enough to me thats all I know.
Boats are expensive enough, few extra bucks for the Merc I will never question again.
 
I flipped between RP auto and marine gear lube. Depended on discounts and availability. I changed mine at least twice a year, most times 3. When I relied on dealer service of lower unit I had 3 lower units blown. Switched to all service by me and never a problem in 5 years. If you run in rough water a lot or weeds you should change more frequently some bass pros change every 3-4 weeks. The less you have a dealer touch your motor the better...
Sidebar... I think I read the evinrude G2 has a window or something to check LU lube... not sure, may have been drunk at the time.
 
I was on Royal Purple's website and I read a answered question by RP to a person asking a question about their Marine gear oil. The reply included by RP that if they were unable to use the marine version to use the Max Gear version. Both oils were fine for outboard use. So I am suspecting that they are very close to being the same product if not the same product like someone had mentioned a Merc Rep stated to them.
 
+1 ...
I had Merc/QS & YamLubes in my stash - after reading this and "feeling" the gear lubes - just did 1st Merc gear oil and RP HPM in power head ... (In Yamaha) ...
 
Originally Posted By: BrocLuno
I'm with Alarmguy. Merc Gear Lube is tacky and tenacious. More so than any other 90 gear lube except for Redline, which is even more expensive ...


I can't even blast off Merc gear lube with a constant jet of carb cleaner. That stuff is extremely hard to eradicate.
 
Originally Posted By: BrocLuno
I'm with Alarmguy. Merc Gear Lube is tacky and tenacious. More so than any other 90 gear lube except for Redline, which is even more expensive ...


Marie Gear lube should not be tacky. You want the oil to flow well and not stick. Dont be fooled by the Lucas gear oil display with the little crank handle. Tacky oil is great for Chain Saw bars.
 
Merc in general is semi-synish
wink.gif
... I just put their gear oil in my Yam ...
 
I've always run a synthetic or semi-synthetic marine gear lube in my outboards. But, my current outboard specifies nothing more than GL-5 80 or 90 weight.

Anecdotally, I bought a used outboard many years ago. I didn't know anything about outboards at the time, and among many mistakes I made with it (It had been sitting for a LONG time) I ran it without changing or checking the gear lube. When I finally did, the oil I drained was tan and milky, indicating water intrusion. I refilled with a semi synth (PowerPro, I think) and ran it again. Again, there was water intrusion. When I finally decided to tackle the problem, thinking I needed to re-seal the lower unit (when really all I needed was fill and drain plug washers) I pulled the bearing carrier to replace the prop shaft seal. In doing so, I cratered one of the bearings and had to replace it.

Anyway, long story short, even with that kind of abuse, the gears and bearings in the LU were nice and shiny, and after replacing the bearing that I broke, I buttoned it up and ran it for years with no ill effects. As far as I know it's still going strong; sold it to a friend. It's 35 years old now.

That was in fresh water. I still run a semi-synth marine lube in my current motor (in the salt), and have run full synthetic Royal Purple for a year or so, but knowing what I know now, would have no qualms about just using the recommended lube, which is anything I can buy in any auto parts store. I guess the main reason I've been running marine specific lubes is that I haven't seen a synthetic auto lube on the shelf with an 80W-90 rating; the ones I've seen are 75W-90. Not sure that makes any difference at all.

TL;DR. Look at the mfg recommendation and follow that.
 
For me it's once a year oil change - Security for precious memories ...
That RP gear oil looks interesting ... Might be an all purple picture next fall.
(I take pics for warranty and artificial memory) ...
 
Status
Not open for further replies.
Back
Top