OMC "C" lubricant

What kind of oil is "C", SAE 80 or SAE 90. if SAE 80, big deal if I will use SAE 90. It is for a Johnson seahorse 18 hp 1963.

Re: OMC "C" lubricant

Henning..... I've lost track of exactly what viscosity "Type C" (OMC Premium Blend) lube is but this type lube is to be used in the "Electric Shift" or "Hydro Electric Shift" lower units only.<br /><br />The mechanical shift lower units (All Other OMCs), use what is called "HiVis" (80/90w) lube which is readily available at Wal*Mart, K-Marts, no doubt many other like stores, and of course at any marine dealership.<br /><br />You cannot use "Type C" in a manual shift lower unit as the viscosity is too low and gear/bearing damage will result.<br /><br />You cannot use "HiVis" in any electric type shift lower unit as the viscosity is too high for the oil pump to handle properly.

Re: OMC "C" lubricant

Type C = 80w <br />Hi-Vis = 90w

Re: OMC "C" lubricant

Actually the Old Type C lube, now called Premium Blend, is similar to automatic transmission fluid.<br /><br />HiVis is not a 90 hypoid like Yamaha, Suzuki, and older Mercs used. It is a special blend with less viscosity than hypoid 90.<br /><br />UltraHPF is the semi-synthetic oil now recommended for all motors except for the electric shift and electro-hydraulic shift models. There are no viscosity specs but it is a bit thicker than ATF and a lot thinner than 90W.

Re: OMC "C" lubricant

HI! check the viscosity on citroen LMH fulid..its a hydraulic/servo fulid...citroen dritt veit du....

Re: OMC "C" lubricant

Seahorse...this oil stuff is confusing. All I know is I posted is what several Google searches turned up from oil mfgs advertising...not message board info. Many familar mfgs are advertising the marine gear oil with "C" as 80w and and hi Vis as 90w (or 80w-90w multi)...they don't reference hypoid. <br /><br />One early ABOS motor manual I have says to use "C" in most of the under 30hp omc motors from about 1951-1973. I didn't check every motor but all I did check said this. It also states to use regular outboard motor oil as a temporary replacement in the lower unit if "C" is not available. <br /><br />My 1951 3hp Johnson says to "use 90W or equal substitute" on the cowl instruction decal. It seems to me all the omc motors I had without elec shift said to use this up into the 70s. I use the same stuff Joe Reeves says for years in old motors and never had an inkling of problems. I'm running hi-vis in my newer motors.<br /><br />I also ran 90W "service station" hypoid back in the 50s in my omc's...3hp, 14hp & 15hp and never had a problem.

Re: OMC "C" lubricant

so i can use SAE 90/SAE 80w-90?? I belive it is not a very big deal, because the oil in the gearcase is pure grease!!

Re: OMC "C" lubricant

In the late 50's or early '60s, OMC came out with Type B oil to replace the hypoid 90, just like two cycle oil replaced the 16:1 or 24:1 mix of non-detergent 30 weight car oil. Type B evolved to Type C, then to HiVis, then now to UltraHPF. Other companies, not OMC, may say their lubes are 90W, but that is not the factory recommendation.<br /><br />Over the years, materials, lubes, plugs, procedures, and engines change. It is best to use the latest manufacturer's recommendations. Would you want your doctor to treat you using 1951 medical procedures?

Re: OMC "C" lubricant

Seahorse...I agree with that. Use OEM specs and stay safe. Although I do bend the rules sometimes when in a jamb.<br /><br />Interesting take on a Mariner 50hp 4stroke. I was changing the gear lube yesterday and hadn't looked in the manual lately for lube specs so did. The offical owners manual gives not ONE spec (except for fl oz capacity)on what type of lube to run in the lower unit (another reason I don't like merc products). I've always used the merc brand lube but you would think merc would have published what to use. I bought the motor new so all the paperwork is here and nowhere does it give gear oil info. Specs for this motor in Clymer's is GL5 90w...identical to auto lube and smells, feels just like the merc lube. The difference in cost about 5X.