Lower Unit Repair 1970 Johnson 70 HP 70TLCOS

adangelo77

Cadet
Joined
Dec 7, 2018
Messages
23
Hello,

I have a 1985 70 HP johnson - J70TLCOS. I fear the lower unit gears may give out on my in the next season or two. When I Changed the lower unit oil this year there were metal shavings and the oil was a light grey color. I just bought the boat a season ago, the engine runs amazing and was reliable all summer but I was disappointed when I winterized and found the oil in the shape it was in. The last owner said he changed the oil annually.

Anyways, I came across a guy selling a 1977 70hp and it seems like much of the gear parts are the same. Would the parts be interchangeable if I needed to re do the gears on my 1985? The seller also said he may have a 1985 lower unit but he is going to get back to me.

Thank you!!!!
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,585
Well first things first. Welcome about. :welcome: Always great to have a new member...

One thing you can do is search the net for a breakdown of your engine (model number and year) and the suspect parts engine as well. That break down will offer part numbers. And if those part numbers are the same, it will work. If not, they won't. I suspect it could work, but verification is easy to do. JMHO
 

Crosbyman

Rear Admiral
Joined
Nov 5, 2006
Messages
4,910
changing the oil every year is not a garante against wear and…. fish line .

gears are obviously in bad shape . check out utubes … lots of coaching available
 

flyingscott

Fleet Admiral
Joined
Apr 8, 2014
Messages
7,985
I believe the 77 unit will bolt right on to your motor. The casting is a different shape but it should bolt right up.
 
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