Lower unit lubes

mommicked

Lieutenant Commander
Joined
Dec 15, 2009
Messages
1,700
I've used Yamahas gear and motor oil exclusively since I bought my 03 F90 in 07. This year I bought Quicksilver products at the new Bass Pro Shops that opened near me and saved about $25. I have changed the motor oil and she purrs like a kitten on the muffs. I've drained the LU and read on the Quicksilver High Performance SAE 90 label not to mix it w any other gear lubes. Will this cause a problem w the residual Yamaha lube in the LU if I change the fluids brands? I see the Quicksilver gear lube is blue/green and smells nothing like the Yamaha lube that looks and smells like all the standard auto type gear lube I've ever used. Any advice is appreciated.
 

BaileysBoat

Senior Chief Petty Officer
Joined
Sep 29, 2008
Messages
716
Re: Lower unit lubes

I switched to the Quicksilver HP gear oil at the first oil change when my F150 was new. 800 hours later and never had a problem.
 

Bamaman1

Lieutenant Commander
Joined
May 15, 2011
Messages
1,895
Re: Lower unit lubes

You've got no problem draining your l/u grease and replacing it with the Mercury 90 weight.

I refuse to pay the price the Yamaha dealers want for their lubrications, anyway. I just use Pennzoil lower unit grease that is available in the sporting goods department at Walmart for $5.50. I also refuse to use Yamaha oil filters (price) and have cross referenced the same oil filters online to a bunch of different reasonably priced brands, like Wix. I've been using diesel oil (universal oil) in my F150, as it does a perfectly good job and it's very inexpensive. It won't work in any motor with a catalytic converter,however. I'm going to switch over to Mobile 1 EP--a far superior product to just about any other synthetic oils on the market.

I just hate to change the oil, filter, l/u grease after only 18 hours usage in the last year.
 

T_Herrod

Petty Officer 1st Class
Joined
Apr 1, 2012
Messages
349
Re: Lower unit lubes

The reason for the different color and smell is likely that the Quicksilver product is a synthetic blend. I have been wrestling with trying to decide if i should switch to synthetic or not in my 2 stroke 50hp unit.
 

mommicked

Lieutenant Commander
Joined
Dec 15, 2009
Messages
1,700
Re: Lower unit lubes

I couldn't wait for a reply and used the Quicksilver, it does say " .....and all outboards" on the jug. I did let the LU drain all night long and replaced the plug seals. The old oil was slightly milky, probably because I had apparently installed a new seal on the top plug and did not remove the old one from the housing the last time I changed it. I was shocked at the price of the new synthetic Ring Free at the dealer, what's up w that? I have enough of the new and a bottle of the old Ringfree to last a year or more but I'm sure I didn't pay that much for the syn. RF I bought last year. After 4 top offs w non Ethanol gas, changing the spark plugs, water filter, and oil, my motor hit on the first and cranked on the second spin and purrs smoothly after sitting idle since January. It has'nt done that since I bought it in 07, if it sat for more than 3 weeks it was hard to start and sometimes took 5 or 7 tries as it would knock off and need restarting. Thanks for the replies and advice.
 
Last edited:

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
9,116
Re: Lower unit lubes

have read that lower units that have bushings in them should not use full synthetic , just a word of caution.
Now all you have to do is figure out what all in your lower unit
 

mommicked

Lieutenant Commander
Joined
Dec 15, 2009
Messages
1,700
Re: Lower unit lubes

have read that lower units that have bushings in them should not use full synthetic , just a word of caution.
Now all you have to do is figure out what all in your lower unit

The Quicksilver "High Performance" SAE 90 I used is apparently not synthetic or a blend, it doesn't say "synthetic" anywhere on the jug.
 
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