Lower gear oil drain plug seal for Johnson outboard

R

Robbyracks

Cadet
Joined
Jun 27, 2022
Messages
29
Hey folks,

I have a 1990 50 HP Johnson (VJ50TLESR). What size seal should i be using? I believe the 3/8-16 is the correct size but I just want to confirm before I order them on Amazon. Thank you!
 
C

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,217
3/8-16 is a spec for a bolt. Is that what you are asking?

I would expect you could ask for a generic J/E plug. Don't forget the fiber gasket.
 
R

Robbyracks

Cadet
Joined
Jun 27, 2022
Messages
29
Chris1956 said:
3/8-16 is a spec for a bolt. Is that what you are asking?

I would expect you could ask for a generic J/E plug. Don't forget the fiber gasket.
Click to expand...
Specifically referring to the little blue seals that sit between the bolt and the port of the gear case. TY
 
C

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,217
Those blue seals are avail on Amazon, as well as a lot of places. Just order Johnnyrude or Mercury ones. They are the same. Yammies are a bit smaller.

 
C

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,217
I use a hand impact driver to tighten the gearcase plugs. If you are strong and have a big, slotted screwdriver, you can tighten by hand.
 
C

cyclops222

Commander
Joined
Mar 21, 2024
Messages
2,292
DO not use any impact. The washers can be squashed & leak.
Those seals should last at least 20 years. Mine are much older.
 
A

airshot

Vice Admiral
Joined
Jul 22, 2008
Messages
5,540
Chris1956 said:
I use a hand impact driver to tighten the gearcase plugs. If you are strong and have a big, slotted screwdriver, you can tighten by hand.
Click to expand...
I made a large flat blade on a screwdriver that has a square shaft. The blade fits the slot very well and the square shaft allows for a little extra leverage. Made it years back and seems to fit alk the gear case screw slots.
 
A

airshot

Vice Admiral
Joined
Jul 22, 2008
Messages
5,540
cyclops222 said:
DO not use any impact. The washers can be squashed & leak.
Those seals should last at least 20 years. Mine are much older.
Click to expand...
A cast aluminum housing is not a good place to use an impact tool. Better off to make a tool that works with no sharp impact.
 
M

Mc Tool

Chief Petty Officer
Joined
Aug 7, 2024
Messages
434
🙄 just google " evinrude/johnson gearcase drain plug "
I got ½ dozen with sealing washers off timu for a couple of bucks .
They fit my 6hp zuki, 35hp Honda and the Tohatsu m18
 
C

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,217
Really? I have been using a hand impact tool for 40 years on my gearcase screws. Tighten the screw, and then tap the impact driver to tighten it a bit more, maybe 1/4 turn. My gearcase plug washers last exactly 1 season, not 20 years.
 
JohnnyGuy

JohnnyGuy

Petty Officer 2nd Class
Joined
Aug 24, 2017
Messages
193
Chris1956 said:
Really? I have been using a hand impact tool for 40 years on my gearcase screws. Tighten the screw, and then tap the impact driver to tighten it a bit more, maybe 1/4 turn. My gearcase plug washers last exactly 1 season, not 20 years.
Click to expand...
The impact just isn't needed. What you can tighten to by hand is sufficient. Using the impact increases risk of damage, not to say that it will damage it, but it certainly increases the risk.
 
C

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,217
Does anyone realize that a hand impact driver uses my hand and a hammer? I suppose I could damage the gearcase threads, if I got a BFH and wailed on it. That is what it would take.

I, for one, do not want the gearcase plugs to work loose over the season. That will ruin the gearcase for sure.....
 
A

airshot

Vice Admiral
Joined
Jul 22, 2008
Messages
5,540
Chris1956 said:
Really? I have been using a hand impact tool for 40 years on my gearcase screws. Tighten the screw, and then tap the impact driver to tighten it a bit more, maybe 1/4 turn. My gearcase plug washers last exactly 1 season, not 20 years.
Click to expand...
Some folks realize what a tap is, while others might use a 20# sludge hammer ! When the word "impact driver" to a person not familiar with these types of tools gets carried away, ugly things can happen.
 
C

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,217
Gee, that is why I said "Hand Impact Driver", vs "Air Impact Driver".

Does anyone not know what a BFH is? I will save time. it is a big hammer.
 
M

Mc Tool

Chief Petty Officer
Joined
Aug 7, 2024
Messages
434
Haven't done this myself but a friend who suffers paranoia about drain plugs with nylon (or whatever they are ) sealing washers and he dunks them ( the screw and washer ) in a cup of boiling water to soften them just before installing them and then hand tightens them wth the bf screwdriver.
I think the washer not only seals but also acts as a sort of friction lock .
I dont think there is any correlation between the likelihood of a fastener coming undone by itself and the potential disaster if it does . If you do it right the drain plug is no more likely to "fall out " than a head stud .🙂
 
You must log in or register to reply here.
Top