Oil leak - final drive boot

[DrFarkoff]

Okay So Picture of Crown wheel side??

Does the alloy cone spin in the outer steel part ?

Or the conical bearing on the alloy ?

 

[rustychain]

Here you go (I was all focused on the wear marks!).

Nothing seems to spin that shouldn't.

The cone bearing seems to roll smoothly.

The second picture shows the gap between the back of the crown wheel and the worn face in the picture after it. There's no contact so now I'm wondering if the wear that I was getting all excited about is historic.

 

[DrFarkoff]

Stand the gear set up on the wee bearing (CAREFULLY ) and take a shot down into the big bearing

 

[rustychain]

Stand the gear set up on the wee bearing (CAREFULLY ) and take a shot down into the big bearing

Are these what you were after?

 

[DrFarkoff]

the rivets are all there So that is good

We need to work out where the sparkles are coming from

All that rotates in there is the Crown wheel and drive pinion so .......

Personally I think I would tie the front wheel to the stand and with help start the bike and put it in gear and spin the assembly (Light clutch pressure so as not to induce too much lash in the gearbox and have a drain pan below the FD

and try and flush from the pinion through the rear bearing section with atf or something like that That may pick up any sparkles in the area by the wee hole and flush them out where you can see them

Also is the alloy cone where the small bearing mounts, fixed firmly in the steel outer?

Is the smaller bearing tight and is the shim between the bearing and the cone fixed and not spinning

 

[rustychain]

Ok, I've done that and no more glitter came out.

Shall I put it all back together, ride it for a bit and see if the glitter fairy returns?

There was a very small amount of lateral play in bevel gear at the drive shaft end. Could the shaft bearing be on its way out? Possibly grasping at straws!

 

[DrFarkoff]

I think if it spins freely with no obnoxious noises and it is not Hanging" out of it it should be serviceable and just monitor it ??

Does the big bearing spin freely with just a spinning noise and no roaring or growling Use a teaspoon or two of light oil or ATF dribbled in to provide a little lubrication

The only thing I can think of is possibly de chroming of the balls for the sparkles

 

[rustychain]

Big bearing runs nice and smooth. Hard to see if there's any bearing 'delamination' due to the cage. I did a flush and nothing came out.

The bevel gear seems to rotate fine.

I'm going to rebuild it and see if I can reproduce the problem.

 

[mikeyboy]

I’d suggest the input “nose “ bearing is worn,
You state there is a small amount of play.
Grip the input spline lightly with some mole grips and give it a wiggle.
The metal particles will possibly be the case hardening starting to fail,
Once this happens they will degrade pretty quick.

 

[rustychain]

I’d suggest the input “nose “ bearing is worn,
You state there is a small amount of play.
Grip the input spline lightly with some mole grips and give it a wiggle.
The metal particles will possibly be the case hardening starting to fail,
Once this happens they will degrade pretty quick.

Thanks for the suggestion Mikey.

The glitter is metallic which suggests that it's likely from a bearing.

By the nose bearing, do you mean item 7 on this diagram?

 

[mikeyboy]

Thanks for the suggestion Mikey.

The glitter is metallic which suggests that it's likely from a bearing.

By the nose bearing, do you mean item 7 on this diagram?
View attachment 292856

Yes

 

[rustychain]

I've just rebuilt the drive so will get a few hundred miles in to see if the glitter fairy returns.

If she does, then I'll get that bearing replaced (and the seal while that's being done).

 

[rustychain]

After about 400 miles I can confirm that the glitter fairy is still doing her thing.

Rainbow is my nearest indie but isn't equipped to do the bevel bearings.

Any recommendations for this type of work? Happy to post it.

 

[mikeyboy]

I can sort it,no prob

 

[mikeyboy]

Input pinion nose bearing

 

[mikeyboy]

Input pinion seal

 

[mikeyboy]

Compression ring,(input seal runs on this)

 

[mikeyboy]

Crownwheel inner taper.

 

[mikeyboy]

The marks on the casing are just down to a low spot on the casting when machining the face on the last photo

 

[rustychain]

As you'll have probably guessed if you've been following this thread, the FD is with Mikeyboy for a full rebuild (all bearings replaced, new seals etc).

The above photos are of what he found yesterday (it only got delivered yesterday, so swift work!).