Are the gearbox and Lower unit the same thing?

[SCRS80]

I am new to the forums and new to the world of boating also. I was given a 16' Glassmate with a 1968 Evinrude Big Twin 40 with selectric shift. My question; are the gear box and lower unit the same thing? I took it apart and replaced the impeller and thermostat and the oil that came out looked good. What kind of oil do I use to replace? I don't have a manual for it, been looking for one. While Im asking, what does OMC stand for? I have seen the abbreviation several times but have no idea what it means. Thanks in advance.

 

[rrw]

Re: Are the gearbox and Lower unit the same thing?

I believe the gearbox is the lower unit, its just a reference to it as a gearcase being that it encases the lower gears. It takes a special gear lube, lower unit oil, available at most hardware stores, auto part stores, boat dealers, etc you should get a special pump (cheap) and fill lower unit from bottom until it comes out the top, then quickly replace the bottom plug . Omc stands for outboard motor corporation

 

[Chinewalker]

Re: Are the gearbox and Lower unit the same thing?

I believe the gearbox is the lower unit, its just a reference to it as a gearcase being that it encases the lower gears. It takes a special gear lube, lower unit oil, available at most hardware stores, auto part stores, boat dealers, etc you should get a special pump (cheap) and fill lower unit from bottom until it comes out the top, then quickly replace the bottom plug . Omc stands for outboard motor corporation

To clarify - this unit uses a special oil - NOT the kind of lower unit oil found at hardware stores. It takes something called Type C, specifically for electric shift units.

OMC initially stood for Outboard Motors Corporation in the 1930s, but by the 1960s when your motor was built, it was Outboard Marine Corporation.

 

[Tim Frank]

Re: Are the gearbox and Lower unit the same thing?

I believe the gearbox is the lower unit, its just a reference to it as a gearcase being that it encases the lower gears. It takes a special gear lube, lower unit oil, available at most hardware stores, auto part stores, boat dealers, etc you should get a special pump (cheap) and fill lower unit from bottom until it comes out the top, then quickly replace the bottom plug . Omc stands for outboard motor corporation

To clarify, replace the top screw first. The partial vacuum created will greatly reduce fluid loss while you replace the bottom screw.

 

[SCRS80]

Re: Are the gearbox and Lower unit the same thing?

So I should have both screws out while replacing the oil with type c?

 

[Chinewalker]

Re: Are the gearbox and Lower unit the same thing?

Yes, fill from bottom up with motor vertical - helps minimize air pockets. Place top screw in hole to hold suction and reduce oil loss when you replace bottom screw.

 

[Tim Frank]

Re: Are the gearbox and Lower unit the same thing?

So I should have both screws out while replacing the oil with type c?

Get that manual!

oem manual evinrude 40 hp 1968 | eBay

there are a few on eBay.

 

[seahorse5]

Re: Are the gearbox and Lower unit the same thing?

The old OMC Type C oil is now sold by Evinrude and called Premium Blend. Off brand oils for electric shift engines still refer to the old Type C label.

Lower unit , gearcase and gear housing are used interchangeably in the marine industry. The FOOT is also slang for the lower unit - used mostly in the South.

 

[SCRS80]

Re: Are the gearbox and Lower unit the same thing?

I looked today for "type C" and couldn't find any reference to it. I did locate some Quicksilver Brand gear oil at Wal*Mart that says "For ALL types of outboard applications". in your professional opinion, will this work?

 

[seahorse5]

Re: Are the gearbox and Lower unit the same thing?

i looked today for "type c" and couldn't find any reference to it. I did locate some quicksilver brand gear oil at wal*mart that says "for all types of outboard applications". In your professional opinion, will this work?

no !

 

[SCRS80]

Re: Are the gearbox and Lower unit the same thing?

Thank you, Ill keep looking and if necessary order online

 

[lindy46]

Re: Are the gearbox and Lower unit the same thing?

NAPA can order the type "C"