Lower unit lube..

[Scaaty]

I have 4 smaller under 20 horse outboards that see little use over the summer. None left in the water. But regardless, I drain and refill the lower units in the fall. Lower unit specific oil is getting a little expensive for this. Is there an auto equivalent (like plain old 80/90, or 80/145) that will work just as good, or would foaming be a problem? Thanks in advance.

 

[Scaaty]

Re: Lower unit lube..

Come on, its only an oil question!

 

[Perfidiajoe]

Re: Lower unit lube..

If they see that little use, you can just crack the drain plug, (lower) if no water comes out it's ok leave the oil alone. IMHO, Joe

 

[BillP]

Re: Lower unit lube..

If foaming was a problem in boat gears it would be a problem in auto gears. 90w auto gear oil was specified and used many years in OBs and they did fine. I'm talking only from personal experience on a few motors, not anything else. <br /><br />My 1996 Mariner says use Quicksilver or SAE 90W GL5. Marine gear oil may be better, at least that's what the glossy ads say. I doubt we see it in real life but I use marine grade just to play safe.

 

[fishingdan]

Re: Lower unit lube..

I read recently that marine gear lube has an additive that allows the lube to continue to lubricate the gears even if some water gets in the lower unit. The additive forces the water and lube to mix instead of the lube floating on the water (the gears are closer to the bottom to the lower unit that the top).

 

[ZmOz]

Re: Lower unit lube..

I would switch to synthetic and only change it every few years. Amsoil claims up to 10% water in theirs is ok. I've found it to be cheaper too - only about $7 for a quart of amsoil or $3 for a 10oz tube of regular lube.

 

[Scaaty]

Re: Lower unit lube..

I think I'm just going to see if I can get some 2 1/2, or 5 gallon containers of lube. Have a total of 7 gear cases (plus a LOT of motorcycle gearboxes), so I change way too much oil. I'm going to either drain and store, or sell off something....getting overloaded here, and the fixed income is getting me nowhere ahead of the game. Thanks guys...

 

[MCM]

Re: Lower unit lube..

Hi, I don't know what year or model motors youv'e got but my '75 Johnson service manual recommends Dexron tranny fluid as a replacement for their premium blend gear lube. I haven't tried it but might be worth checking the way oil prices are going<br />