Oily back tyre revisited

[MattW]

Went out for a decent 100 mile or so spin last weekend and despite various prayers and sacrifices, I'm still getting oil spots on my back tyre (and corresponding spots on the shock 'mudguard') as I referred to in this previous thread:
http://www.ukgser.com/forums/showthread.php?t=173934
It wasn't as bad as shown in the previous thread, but there nonetheless.

I'm at a loss to think where its coming from and would appreciate any ideas from them as knows...

The facts:

1994, 1100GS 34,000 miles

The leak seemed to start after I'd changed the gearbox and FD oils (coincidence?).

I used Halfords brand semi-synth 75w90 GL5 oil in the GB and FD (I've heard that synth oils can get by seals sometimes - could it be this?)

The leak is small - just the drops - and is definitely from the back of the gearbox. It appears on the lower rear edge of the gearbox casting directly below the swingarm and seems to fly off backwards in the airstream, hitting the tyre (but only the offside edge). When parked up it drips onto the exhaust collector box and off the forward end of the torque arm.

The leak seems to start when the gearbox gets up to temperature - I start to smell gearbox oil when stopped and the spots on the back tyre start to appear.

After I'd first noticed it a month ago, I checked both levels - the GB may have been slightly overfilled (after I noticed the leak, I checked the level with a 'hot' gearbox and some drained from the fill plug).

Steptoe advised me to check the swing arm to FD boot - there was some in this when I first noticed the leak (although apparently not enough to indicate a gearbox output seal leak - picture in the thread I refer to above). However after this weekends ride, the boot was bone dry - I guess this rules out the gearbox output seal? - Could the swingarm to gearbox boot be leaking and allowing oil to get out before it flows down the swingarm?

The only other place I could imagine the oil getting out is the gear position / neutral switch - is this likely?

As I say, I'm stumped - the only thing I can think of trying before I bite the bullet and remove the swingarm (which I'd rather not do unless I have to ) is to change the GB oil again to non-synth EP90 GL5 in case its the different oil type which precipitated the leak...

Any ideas greatly appreciated.

ta
Matt

 

[Steptoe]

Check the airbox drain plug is fully tightened.

Check the clutch slave cylinder where it attaches to the back of the gearbox.

If the gearbox seal inside the clutch pushrod tunnel is leaking in can drip where your appears to be leaking from the slave cylinder/gearbox gasket , but usually ends up in the clutch housing.

Your the only one with the bike in front of you, everyone else is just guessing at where the leak is from, including me.

 

[MattW]

Check the airbox drain plug is fully tightened.

Check the clutch slave cylinder where it attaches to the back of the gearbox.

If the gearbox seal inside the clutch pushrod tunnel is leaking in can drip where your appears to be leaking from the slave cylinder/gearbox gasket , but usually ends up in the clutch housing.

Your the only one with the bike in front of you, everyone else is just guessing at where the leak is from, including me.

Sorry Neil - just edited my post to clarify - its an 1100 so a cable clutch.

I know its impossible to to a telepathic diagnosis - I guess I'm just hoping (probably in vain ) that there's some sort of common fault to look for.

cheers
Matt

 

[motobiker]

Don't be worried about the oil you're using. it's what I've always used and is as far as I'm aware possibly the most popular oil for the job due to its ready availability. I have never seen any comments about semi synth being unsuitable for this particular job. The most critical aspect being that its close as dammit the recommended spec (80w/90) and absolutely MUST be GL5.

 

[MattW]

Don't be worried about the oil you're using. it's what I've always used and is as far as I'm aware possibly the most popular oil for the job due to its ready availability. I have never seen any comments about semi synth being unsuitable for this particular job. The most critical aspect being that its close as dammit the recommended spec (80w/90) and absolutely MUST be GL5.

I'm sure you're right Tony - I suppose I'm just clutching at straws really! I just can't help but think it was something I did when I changed the gearbox oil.

The area around the clutch actuator is dry, so I think that's ruled out.
There's no oil to speak of in the swingarm (which should rule out the GB output seal as long as the swingarm to gearbox boot is installed correctly / is intact)
But there's oil seeping out from what appears to be the right hand side of the GB rear face (although it could be tracking from somewhere else).

Short of a cracked GB casing (but why should it crack on the rear face?) the only thing it can be is either the output shaft seal or the gear position switch.

I'll check the airbox drain plug tonight (once I've found it...)

After that, I guess I'm looking at a swing arm removal...

Ah well, all adds to my GS fettling experience

 

[MattW]

Well, I've just checked the airbox drain plug which was tight and just had a couple of drops of oil in it.

So, there's no other way round it, it's either the gear position switch or the output shaft seal - I'm going to have to remove the swing arm

Just in case anyone looks in this thread - If anyone is aware of a how-to for this on here or ADV, I'd appreciate a pointer (I have searched honest!) I have a clymer, but my experience thus far is that it can over-complicate some jobs. I assume it's necessary to remove the FD as a separate item rather than taking it off as a unit with the swing arm?

ta
Matt

 

[Trullion]

Matt,

I almost don't dare mention this in view of the earlier aggravation you had, but when my head gasket was on the way out (on my RS) I got oil spots on the back wheel. It took me a while to figure out where it was coming from (but there's a lot of fairing covering everything on the RS, so probably less likely on a GS).

Only saying...........

 

[MattW]

Matt,

I almost don't dare mention this in view of the earlier aggravation you had, but when my head gasket was on the way out (on my RS) I got oil spots on the back wheel. It took me a while to figure out where it was coming from (but there's a lot of fairing covering everything on the RS, so probably less likely on a GS).

Only saying...........

It did actually cross my mind, but the heads are ok (now at least!). It's definitely gear oil and the odd drop that falls when the bike's parked is falling from the forward end of the torque arm (having run off the rear, bottom edge of the gearbox casting).

 

[(RIP) ugg]

to save assuming where the oil is coming from

get yersen some talc powder, and blather the area where the oil is supposed to be leaking from , like the gearbox area and swing arm to gearbox.

let it settle , some will drop off , but most will stay on with a thin covering.

go for a ride and look at where ye thought oil was leaking, the oil will stick to the talc and give yer a trace area to look from.

i used this method before and i thought my top bolt on a casing was leaking, it turned out it was a lower one , but the vortex air flow of the casing threw the oil up on top of my casing , makin me think it was coming from the top..


worth a try


ugg

 

[(RIP) Kaister]

wot ugg says

we used to have to do this for black engined gixxers - as recommended by suzuki

 

[MattW]

Thanks for the tips guys - I used the talc method to trace a cylinder head leak a couple of months ago, so I know it can be pretty effective

However, in this case, the oil is coming from the little slot between the bottom of the swingarm and the bottom lip of the gearbox casing - impossible to get talc on the back face of the gearbox (and them impossible to see it without removing the swingarm!).

So, the swing arm's got to come out. To be honest, I'm ok with it - as the bike's done 34k, it'll be a good chance to check the paralever and swingarm bearings. I just need to research a good method for re-torquing the bearing pre-load / locknuts without the special tool.

I'm sure I read something about locktiting the pre-load screw and using a marker pen to mark its position once you've torqued it (and then possibly leaving it for the locktite to go off?) before attacking the locknut. But I'm bu**ered if I can find it (and I can't remember if I read it on here or ADV).

cheers
Matt

 

[Stewart H]

I think its on ADV, theres a really low torque on the allen bolt bit then some fairly serious tight on the locknut, is your hot air gun ready ? Let me know how it goes, I am fancying stripping mine, I might even get a gear indicator that says something apart from 3
Stewart

 

[MattW]

I think its on ADV, theres a really low torque on the allen bolt bit then some fairly serious tight on the locknut, is your hot air gun ready ? Let me know how it goes, I am fancying stripping mine, I might even get a gear indicator that says something apart from 3
Stewart

Yep - hot air gun's ready to go (just need to make a nozzle to narrow the blast down a bit - don't want to burn the powder coating off the swingarm )

I'll probably attack it this weekend - I'll let you know how it goes....

 

[ianboydsnr]

Yep - hot air gun's ready to go (just need to make a nozzle to narrow the blast down a bit - don't want to burn the powder coating off the swingarm )

I'll probably attack it this weekend - I'll let you know how it goes....

You should'nt burn the powder coating, just point it at the center of the nut, never used any nozzle on mine, you dont need any special tools either, tighten the allen slowly untill it seats, then slacken off slightly untill you get some movement, then back in between the two, you will probably get it wrong using the torque wrench anyhow as it relys on getting all the threadlock off, hold the allen key, whilst you spanner the lock nut tight, mark the allen with a pen,at 12 oclock then torque the lock bolt up using a socket, making sure the mark is still at 12 oclock

 

[Colban]

I think its on ADV, theres a really low torque on the allen bolt bit then some fairly serious tight on the locknut, is your hot air gun ready ? Let me know how it goes, I am fancying stripping mine, I might even get a gear indicator that says something apart from 3
Stewart

Heres a link to ADVrider Hall of Wisdom.All you need to know should be here.
http://advwisdom.hogranch.com/Wisdom/

Unless your bike REALLY needs to come apart,not just for a dodgy switch,i'd leave well alone.
Maybe you'll enjoy spending a day in the garage swearing a lot.

Back to the leaky gearbox....
I've seen a picture of a very finely cracked casing on an 1100,by the o/s footrest.Looked but cant locate the thread on here or ADVrider.
Have you dropped the bike at all on that side and have you had a good look around/behind the o/s footrest /brake mount?.

 

[MattW]

Heres a link to ADVrider Hall of Wisdom.All you need to know should be here.
http://advwisdom.hogranch.com/Wisdom/

Unless your bike REALLY needs to come apart,not just for a dodgy switch,i'd leave well alone.
Maybe you'll enjoy spending a day in the garage swearing a lot.

Back to the leaky gearbox....
I've seen a picture of a very finely cracked casing on an 1100,by the o/s footrest.Looked but cant locate the thread on here or ADVrider.
Have you dropped the bike at all on that side and have you had a good look around/behind the o/s footrest /brake mount?.

Thanks Colban,
I've seen the same pictures - the lug on the gearbox that the subframe fastens to. Mine's fine - I've been over it with a fine tooth comb (and I've just fitted gearbox 'hard parts' to help stop this happening in the future). The only place it could be cracked (where I can't see it) is on the rear face of the gearbox, but I think its much more likely to be the output seal (although it'd also have to have a displaced / broken gaiter) or the gear position switch.

The link isn't in 'Wisdom' on ADV - I think I remember it being buried in the middle of a vast thread somewhere....

I don't think I've got much option but to remove the swingarm - I can't put up with it leaking (especially when its depositing oil onto my back tyre). While I'd rather be riding it, if it needs work I'd rather fix it than 'make do'
cheers
Matt

 

[Packer]

I can t be certain that it was an 1100 but I've seen a link somewhere that shows the entire rear wheel, fd, swing arm etc. removed as a single unit.

 

[MattW]

I can t be certain that it was an 1100 but I've seen a link somewhere that shows the entire rear wheel, fd, swing arm etc. removed as a single unit.

Thanks Packer,
I've seen a link (by Steptoe on here) showing the gearbox / swingarm / FD removed as a unit, but not just the swingarm / FD.

That said, I've gotten used to the thought of taking the FD off first now - just need to find the best method of retorquing / locking the paralever and swingarm bearings.

cheers
Matt

 

[BrianR]

Matt

swingarm and FD will come out as one never done it this way and not sure if you can get the shaft into the GB output when putting it all back together.

I have a torque wrench which goes down to 7Nm. 1/4 drive let me know if you want to use it. cinch to post, make sure you use the right lock tight and i always use nail varnish as witness marks to see that its all staying together after the repair

BrianR

 

[MattW]

Matt
I have a touque rench which goes down to 7Nm. 1/4 drive let me know if you want to use it. sinch to post, make suer you use the right locktight and i always use nail varnish as wittness marks to see that its all staying together after the repair

BrianR

Hi Brian,
Many thanks for the kind offer - However like you, I have a 1/4" drive wrench that goes down to 5Nm (and 3/8" and 1/2" ones to do the rest - tool junkie )
I'm going to stop by Halfrauds tonight and get some Loctite 2701 (although I know some people suggest using a lower grade in case you have to do 'side of the road' repairs ).
Good idea regarding nail varnish for the witness marks
cheers
Matt