Oil leak - final drive boot

[rustychain]

Evening all

I loosened the final drive boot yesterday as there were signs of a slow oil leak. About 50 ml of gearbox oil dribbled out.

Any idea which seal is to blame?

Thanks

 

[Mzokk]

If the oil is running down the final drive housing from the gearbox it will leave a trail in the casing. Pull the boot back and have a look with a torch. Check the level in the FD it only holds 230ml so you should be able to detect a missing 50ml.

 

[KMD]

When a similar issue came about with my first 1150Gs it was the seal going into the final drive from the drive shaft that had failed. To change it requires a special castellated socket, and a great deal of force together with the means to secure the final drive while the force is applied. In the event I was unable to do it, so I took the final drive, new seal and new nut to Barrie Robsons, where it cost over a hundred pounds to have the old removed and the new put in.

 

[rustychain]

Thanks for the responses.

I've just checked the oil level in the FD - noticeably lower that when I replaced the oil earlier this year.

I'd quite like to have a go at this myself (one of the reasons I bought the 1150 is so I can work on it). Any ideas if I can get hold of the required special socket readily in the UK? I've seen the tool KD 2467 mentioned - plenty listed in the States, none in the UK that I could find.

 

[DrFarkoff]

This may not sound like sense, But, here we go

So many times I have come across this on these bikes, They "Burp" and you get the oil in the FD boot

Peel it back clean it out well, use brake cleaner so as not to wreck the boot and drain and replace the FD oil with 85 W 140 GL5 spec check the gearbox level too I would only use 80 or 90 weight GL5 spec in there though

Check it again after a couple of hundred miles If its still doing it Then you only wasted 200 ccs of oil and a half hour of your time

N.B. try and get it half level front to back on the centre stand when filling the FD and its just to the bottom threads of the filler plug

 

[rustychain]

This may not sound like sense, But, here we go

So many times I have come across this on these bikes, They "Burp" and you get the oil in the FD boot

Peel it back clean it out well, use brake cleaner so as not to wreck the boot and drain and replace the FD oil with 85 W 140 GL5 spec check the gearbox level too I would only use 80 or 90 weight GL5 spec in there though

Check it again after a couple of hundred miles If its still doing it Then you only wasted 200 ccs of oil and a half hour of your time

N.B. try and get it half level front to back on the centre stand when filling the FD and its just to the bottom threads of the filler plug

You could be onto something.

This leak has been going on for a while, so it could be the 'burping' you mention. There's also been a misting of oil on the final drive output seal which I was surprised at - the crown bearing and seal were replaced a couple of years ago.

I've not checked the FD breather - could that be blocked and contributing to these symptoms?

 

[KMD]

Thanks for the responses.

I've just checked the oil level in the FD - noticeably lower that when I replaced the oil earlier this year.

I'd quite like to have a go at this myself (one of the reasons I bought the 1150 is so I can work on it). Any ideas if I can get hold of the required special socket readily in the UK? I've seen the tool KD 2467 mentioned - plenty listed in the States, none in the UK that I could find.

I seem to recall seeing a thread a long time ago, and possibly on Advrider not here where someone gave a guide on how to make the tool out of a suitably sized socket. Sorry I can’t be more specific.

 

[rustychain]

I seem to recall seeing a thread a long time ago, and possibly on Advrider not here where someone gave a guide on how to make the tool out of a suitably sized socket. Sorry I can’t be more specific.

I've found that thread - probably beyond my skills (and tools) to make my own!

 

[DrFarkoff]

You could be onto something.

This leak has been going on for a while, so it could be the 'burping' you mention. There's also been a misting of oil on the final drive output seal which I was surprised at - the crown bearing and seal were replaced a couple of years ago.

I've not checked the FD breather - could that be blocked and contributing to these symptoms?

If you gently pry up it should pop up vertically there's an o ring at the bottom on a small pin hole at the top with a little wedge of foam inside

I do tend to clear those off and give them a rinse out in some petrol or something just to remove the heavy oil content

Make sure the little hole is clear and reassemble

 

[Udders]

Excellent advice yet again Dr F.

 

[ELIMINATOR]

Just checked mine, for the first time ever. Decided not to remove the sponge, as it started to come apart when tugged by tweezers.

 

[rustychain]

I've checked the breather - all clear (but no foam, maybe it's an aftermarket part?).

I've dropped the oil and refilled it to the required level. I'll monitor the situation and feedback.

There was some 'metal glitter' on the sump plug (not gritty) - is this normal after the ~6,000 miles since I last changed it?

 

[DrFarkoff]

I've checked the breather - all clear (but no foam, maybe it's an aftermarket part?).

I've dropped the oil and refilled it to the required level. I'll monitor the situation and feedback.

There was some 'metal glitter' on the sump plug (not gritty) - is this normal after the ~6,000 miles since I last changed it?

"Some" is usual

BUT a christmas tree of glitter is a problem

 

[rustychain]

The bearing was replaced ~10,000 miles ago by Rainbow. Hopefully it was done to spec (not in my ownership at the time).

I guess it depends what size Christmas tree we're talking about...




...

 

[theoneandonly]

dust is normal , that's not dust. imho

 

[DrFarkoff]

Okay IF I were you I would drop off the Wheel and the caliper

Clean the fuck out of the Allen sockets (7mm if I recall correctly)

Drain your oil into a clean container

and pop that cover with the crown wheel and drive off and have a look inside
They look like alloy chunks so it may be the wee hole

I will try to find the link about one I did for a guy who brought it home

Found It https://www.ukgser.com/community/threads/anyone-spot-the-problem-here.230978/

 

[rustychain]

Okay IF I were you I would drop off the Wheel and the caliper

Clean the fuck out of the Allen sockets (7mm if I recall correctly)

Drain your oil into a clean container

and pop that cover with the crown wheel and drive off and have a look inside
They look like alloy chunks so it may be the wee hole

I will try to find the link about one I did for a guy who brought it home

Found It https://www.ukgser.com/community/threads/anyone-spot-the-problem-here.230978/

I'll take this course of action - thanks for the suggestion and links.

What's the worst case outcome if it is alloy from the wee hole - a new FD casing? Or let's wait and see what I find first?

 

[mikeyboy]

What was sound advise ten years ago may not be the best course of action now.
Just replace the big bearing,with a worn taper obv now results in premature failure of said big bearing.
Failure of input seal could be down to corrosion on the compression/spacer ring ,wear on the pinion bearings or just the seal worn out.
Do it cheap,do it twice would be a very relevant phrase now with an 11xx final drive

 

[DrFarkoff]

I'll take this course of action - thanks for the suggestion and links.

What's the worst case outcome if it is alloy from the wee hole - a new FD casing? Or let's wait and see what I find first?

Check it out and show us what you have

 

[rustychain]

Me again. I've stripped down the FD. The 'wee hole' looks fine.

What doesn't seem right are the areas of uneven wear on the surfaces that I've marked up on the photos. You can see the shiny metal and the contrasting metal face/black painted finish.

I'm pretty confident the glitter is the shavings from the wear points (should there even be any wear?).

The main bearing seems in good nick.

It looks like something hasn't been fitted square or there's play somewhere that is allowing this rubbing/wear. There was no play in the wheel that I could detect.

Could the smaller tapper bearing be at fault?

Grateful for your thoughts.