Lower Unit Oil

RDJuhl

Petty Officer 2nd Class
Joined
Jun 5, 2010
Messages
121
We just purchased a used Ranger boat and motor. I am new to boating...so need some advice regarding the Lower Unit.

From reading service manuals, it appears we should change the lower unit lubricant...can anyone provide advice on the correct gear case oil to use...it appears there are some choices at our local Walmart.

The motor is a 1973 Johnson 85 HP 4 Cylinder.
Thanks
 

Bifflefan

Commander
Joined
May 27, 2009
Messages
2,933
Re: Lower Unit Oil

Regular Merc Hi perf is just fine, as long as it a 73, and not an electric shift.
If its a 72 or older then you need fluid for an electric shift.
Make sure before you add new.
Also you will need a pump and fill it from the bottom hole until it comes out the top hole, then plug the top hole and remove the pump and plug the bottom hole.
There are vids on you-tube, watch a couple if you have never done it before.

Also, Welcome to iboats....:D
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: Lower Unit Oil

Just be sure to have the unit in the running positon when you refill it.

High viscosity outboard gear oil is required. 75-90.
 

Al-53

Chief Petty Officer
Joined
Jul 17, 2008
Messages
491
Re: Lower Unit Oil

On a note....make sure you install new plastic plug seals....get them at any marina...do not use the old ones..best way to get water intrusion...also if you get a quart bottle buy a pump for the bottle most auto parts places have them...it screws in the lower drain hole..and you just pump it till you get oil out of the top hole....it cost like 7-8 dollars....saves time...

just make sure you get new plastic plug seals..unless your's has a o-ring built in to plug and just replace them then...

also check drained oil for water or if its milky..then you have water intrusion..new plug seals may cure it...if they were re used before...

the rings are like .60 cents each...get a few lol....have on hand for later

make sure the oil says GL5 on the container...I myself use the Mobil 1 oil 85/90 SAE its a synthetic and really smoothed out the shifting..

Al
 

RDJuhl

Petty Officer 2nd Class
Joined
Jun 5, 2010
Messages
121
Re: Lower Unit Oil

Thanks to all for the advice. I have watched some videos on the procedure...so we should be in good shape...assuming the old oil is not milky.
 

RDJuhl

Petty Officer 2nd Class
Joined
Jun 5, 2010
Messages
121
Re: Lower Unit Oil

ok - I will prove my ignorance...how would I be able to tell if the motor is an electric shift?
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: Lower Unit Oil

The last 85HP with electric shift was the 1972 model. It does not have a shift rod or a shift cable.
 

clearwatguy

Seaman
Joined
Sep 9, 2009
Messages
51
Re: Lower Unit Oil

ok - I will prove my ignorance...how would I be able to tell if the motor is an electric shift?

it would not have a shift lever it would have buttons

if it has 3 push buttons forward nuetral and reverse its electric "evinrude trade name Selectric" get it? select and electric all combined to make a word that sounded REALLY cool in the early 70's to a population that was REALLY into star trek, space 1999 and anything that had the word electronic embellished on it.
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: Lower Unit Oil

it would not have a shift lever it would have buttons

if it has 3 push buttons forward nuetral and reverse its electric "evinrude trade name Selectric" get it? select and electric all combined to make a word that sounded REALLY cool in the early 70's to a population that was REALLY into star trek, space 1999 and anything that had the word electronic embellished on it.

May be, but I think that OMC had electric shift before Star Trek.
 
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