Logo
FULL SITE MENU

Oil seal help

G

Grandriverrat

New member
Hello all! Can anyone tell me how to change the oils seals on a 1988 20 hp mercury. The seals by the propeller. Is this easy? Any help would be greatly appreciated!
 
Just to be straight here, you are talking about the oil seals on the bearing carrier (the seals around the propshaft where the prop shaft goes back into the lower unit)???

Because there are also oil seals:

a big o-ring around the circumference of the bearing carrier itself

an oil seal on the shift shaft,

oil seals on the driveshaft where it enters the top of the gearcase

and little oil seals (washers) on the fill and vent screws of the gearcase...

So before I start throwing details at you, just want to be sure of "which seals" we are taking about...
 
Grandriverrat said:
. The seals by the propeller.
Click to expand...

I've only done two, but they were successful. Here are the simplified steps (it is a tricky job):
-Remove the prop.
-Remove the carrier bearing nut (a ring in the gear housing with notches): It threads in counter-clockwise,so to remove it insert a large screw driver in a notch and tap it out clockwise.
-Remove the bearing carrier (the piece that is in the housing, around the prop shaft): You can rent a slide hammer (if you can figure-out how to attach it to your prop shaft), or you can use this method: Cut some gently tapered shims from hard wood; Place an old circular saw blade over the prop shaft, add a large washer, and then the prop nut; Place wood block against the gear housing to create just enough space between the blocks and the saw blade to slide the shims in; Slide a shim in from both direction, so they over lap, with a set on each side of the prop shaft. Tap them in evenly until the bearing carrier frees-up and can be pulled out of the housing.
-Pull out the bearing carrier. Be careful to retrieve and save all the shims (thin rings) from the back side or the carrier.
-Pull the shaft out of the carrier.
-Drive the oil seal out of the carrier.
-Insert a new oil seal (lip out). Tap it in evenly. Replace o-ring on carrier.
-Install prop shaft
-Replace shims (thinest to thickest)
-Slide carrier back in; Rotate until gears mesh. Some say that reverse is best, so that you don't turn impeller backwards.
-Replace carrier nut, and tighten.
I say "simplified", because there are a lot of little details to be mindful of; you'll see.
 
The bearing carrier is a lefthand thread on the 88 --20 HP.---On some of those the thrust washer ( when reversed ) becomes the tool to remove the carrier.---I do not believe there are any shims in a 20 HP 88 lower unit.----A piece of pipe can also be modified to remove the bearing carrier.-----Fairly simple job once the carrier is removed.
 
I'm doing this today on my merc series 200 20 h.p.

Ill let you know how it goes and if i ran into snags, which i'm sure i will haha
 
Back
Top