Hi again,

Just lubing my final drive splines as I had the wheel off for a tyre change.

When I got the final drive off, a tablespoon of oil fell out of the shaft/FD.

Strange, I thought, as the area was dry when I lubed the splines in the spring. and no signs of leaking oil when parked or around the drivetrain.

However, on inspection, the nut that winds onto the FD splines was loose!

So my questions are:
-Why might the nut come loose? too harsh a downchanges?
-Is that likely to be the cause of the leak? or from somewhere further up towards the 'box..?
-I take it there's a seal in there too somewhere.... replace it before I torque the nut back up, or whack it back together and see how it goes?
-use some kind of locking device/locktite to try to keep the nut in place?

Any opinions/experiences gratefully received!

It's not unusual to find a drop of oil, but if it gets worse you may need to replace the input pinion oil seal (it sits in a threaded ring). How does the drive feel? Perhaps the input bearing is worn? 

That nut should be at 200Nm!

Mike

Johnser wrote:

However, on inspection, the nut that winds onto the FD splines was loose!

Do you mean item #1 in this?

Thanks for the replies,

Yea, #1 in the diagram. Thanks for that pic - most helpful

I will double check in a bit, but the brief examination I gave it showed no signs of a worn bearing, couldn't feel any in/out play, roughness or side to side movement.

The moly-grease that had been flung off of the splines from the previous lube had not been dissolved by the puddle of gear oil, I'm hoping this suggests it might be a fairly new issue and I havn't caused too much unnecessary wear on the pinion/crown.

I take it #4 is the seal so it shouldn't be a huge hassle to replace it so long as I can get #3 out.

Yep, #4 is the seal. There is a tool for the threaded ring........... 

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Hi Johnser,
Here's a simple tool for locking the bevel box while you try to reach 200Nm!
 
https://www.k100-forum.com/t3247-simple-bevel-box-locking-tool

Paul.

Heh, thanks. That tool would've been perfect!

I was scratching my head about how to hold it and in the end put the wheel on, held the square end of the casing in a vice and clamped chocks onto the disk to butt up against the brake mounting holes. With a further brace bar lodged between the wheel spokes it was just about possible to get the torque up to 200Nm.

Very heath robinson and I kind of wish I'd seen that first.

So yea, I decided to whack it back together and see what happens.

cheers!

Good for you. Where there's a will, there's a way.  

Paul.

(Reminded me of a MAD magazine quote "Where's there's a will, there's relatives!)

sidecar paul wrote:Hi Johnser,
Here's a simple tool for locking the bevel box while you try to reach 200Nm!
 
https://www.k100-forum.com/t3247-simple-bevel-box-locking-tool

Paul.

and a great idea paul

made one just last week....hoping I can borrow caferacers "ring release tool" one day for the unlocking of the pinion ...

cheers