Replacing Drive Shaft Oil Seal

[eeetea]

As you may have spotted on another thread, I've had an issue with a major oil leak.  That said, closer investigation showed that its not a fault with the bike or any kind of warranty issue. Just a PITA act of god....well an act of the local council, that insists on saving money by not resurfacing roads but by "surface dressing" instead.  Then they can tick the box to say the roads are maintained, and everyone else can have damaged vehicles.
 
This year alone, my son has had to have a screen replaced on his car, I've had to have my screen repaired, and now this...
 

 

 
 
 
 
So without further ado, here's how I changed my oil seal... this is only a description of past events, by all means, copy at your own risk (terms and conditions apply) 
 
 
 
 
 
 
Step 1. Make a cup of Tea (and Buy the bits)
 
you will require three bits:  The oil seal itself, [93102-40030]  a replacement lock nut [90179-22018], and a replacement spring washer [90208-2202]
 
(BTW mine is a 2015 bike, just to future proof this thread a bit, if you have a later bike you may want to check that nothing has changed?   In fact double check anyway! )
 

 
 
 
Step 2: Getting the Sprocket off.
 
Here's the starting point...

 
 
Make sure the bike is in gear (1st is best), remove the gear change linkage
 

 
 
Remove the side cover (three screws - the third is tucked away behind the breather pipes)
 

 
 
Remove the nylon chain guide (this just slides off)

 
 
Then you need to release the lock nut, by prying the indented areas outwards, so it can then undo [you will note I have the chain off at this stage...DON'T!  Leave it on, otherwise, you'll have to do what I did and put it back on again!]

 
Now the next bit is easier with two people.  Leaving the chain on, wheel on the ground, bike in gear and holding the rear wheel with the brake, you can undo the sprocket lock nut.  (this is a standard RH thread, anti-clockwise for taking it off (counter-clockwise for my US friends)).  I used a rattle gun, but a large breaker bar is adequate. The nut would have been torqued to 95N originally.  It's a 30mm socket that you need BTW.

 
 
Now take the chain off the front sprocket, you can do this easily just by taking out the rear wheel axle and adjustment chocks, moving the wheel forward in the swing arm, replace the axle, just to hold it approx place (but leave the chocks out at this stage - you can stick them back when you replace the chain at end).  This will give you another slack to easily lift the chain off the front sprocket.  [The other option is to slide the chain off with the sprocket, but I think taking the chain off is ultimately easier]
 
 
Remove the spring washer (which just looks like a standard washer but slightly cupped) this slides off, and the sprocket itself, again this just pulls off the splines.
 

 
 

 
and here you see the removed parts AND THAT F***KING piece of surface dressing...aaaGGGGHHHH

 
 
 
Step 3: Make and Drink more Tea, stay calm
 

 
 
 
Step 4: Remove the oil seal
 
BEFORE YOU DO ANYTHING ELSE...Make sure you clean everywhere around. When you take that seal out, the last thing you want is gritty grinding paste chain oil and road dirt getting on that drive bearing!!!   YOU HAVE BEEN WARNED!!
 

 
 
You need patience for this bit.  The seal is a push fit in, and so (theoretically) a pull fit out.  In fact it's in pretty tight.  In my case, the seal was in two halves as you will see in a later photo.  I used a combination of a dental tartar removal tool, some small flat headed screwdrivers and a razor knife.
 
Be very careful not to do anything to damage the engine casing or paintwork. work gently.  I gradually scraped away the rubber seal, and worked the flat head screwdriver between the seal and the case and gently levered out, working ALL the way around, a millimetre at a time. 
 
 
 
If you're patient enough and work around enough, eventually, it will come out. (well most of it..you will notice that half of my seal remains on the shaft where it was cut in half by the surface dressing!...this other bit just slides off)

 
 
Step 5: Fit new seal
 
Fitting the new seal is the reverse of above really, but here's some tips on what I did.
 
Smear the inner and outer edges with clean engine oil (the same that it will be in contact with when in situ), this will just help it push in a little more easily.
 
Line it up and push around.  Make sure its faced up very square and flat to the face of the engine casing, and work it around a little bit at a time so it goes in square and without stretching the centre on the spline.

 
 
Slide the sprocket back on.  I added a bit of copper slip one spline faces with the view that it should make things easier when I come to change it in the future.

 
 
Place the new spring washer over the spline.  Make sure that the surface stamped with "OUT" is facing ...um... out 

 
 
 
Replace lock nut and torque up to 95Nm


 
 
Indent the lock nut using a punch

 
 
Last steps:
 

Replace the Chain,
replace the chain guide
Replace the cover
Replace the gear change linkage (note that there is a scored line on the shaft and a punched dot on the spigot that line up)
Replace the rear wheel and adjustment blocks
Adjust chain tension (LET's NOT EVEN go there!!!!)
 
 
Final Step
 
Drink another cup of tea (and go for wee!)

[wordsmith]

Just a few tea-driven (Typhoo for me) words of appreciation and pleasure at YOUR words and pic on the task, eeetea!
 
Something else to worry about...

[betoney]

@eeetea Thanks for the step-by-step write up, very clear and concise. The procedure doesn't look as difficult as I was imagining.

[eeetea]

No theoretically it's straight forward.  The difficulty lies in a bike a few more years in age with rusted on components.. then you may wish to consider penetrating oils and heat.. though not necessarily at the same time!

[panooch]

Just wondering if a seal puller and starting from the inside of the seal would be any easier?

[eeetea]

The seal was in two bits The chipping had cut through.
 
I don't have a seal puller(and wasn't even aware such a thing exists) but job done. The damage on the casing was by the chipping BTW

[eeetea]

Oooh where's the rest of my piccys. I can only see two. Strange.

[koth442]

Great write up! Thanks for sharing.

[eeetea]

Oooh where's the rest of my piccys. I can only see two. Strange.

Yeah... too bad. This thread is on my Greatest Hits list. PostImage is a free hosting service, so I'm guessing stuff goes missing every now and then. Google scooped some.

I think I loaded up the forum here, rather than hosting myself... all the photos went (Thank you photobucket) from previous posts, so when I posted this I thought I'd do it differently.  
Frustrating that!

[koth442]

Weird... I saw the pictures this morning on my home computer. Don't see them on my work computer though.