Oil leak in the back of the engine

Hi,

One more headacke....
I noticed a couple of oil drops in the garage floor.
I took a look under the engine and it seems there is some oil coming from the are of the hole marked with the arrow in the photos attached.
Has anyone ever seen this? Where could it be coming from?
I am horrorized tinking it could be something like a cranckshaft seal i.e.   ..This would mean taking the engine out of the bike and disassemble it, right?

Thanks in advance for your inputs.

Matias[You must be registered and logged in to see this image.]

Any oil in there is leaking through the rear main bearing seal or the gearbox input shaft seal.

Either of these involves a lot of dissassembly to get to - sorry Matias

Damned...
It must be the main bearing sealing then, because it looks like engine oil.
Is it common for these sealings to fail? The byke has around 40 k on the clock...

Matias wrote:

Damned...
....Is it common for these sealings to fail? The byke has around 40 k on the clock...

I have not got the experience to answer that but there are many very experienced people of the forum such as Mr Roper

Firstly ensure that it isn't running down from above from somewhere like the front airbox drain.

If you are certain it is coming from the slot n the bell housing, (Pry out the now redundant timing plug on the RH side of the bell housing and run your finger around inside and see if it comes out wet. Do NOT do this with the engine running!).

If it is engine oil from inside the bell housing there are three likely culprits. The rear main seal, which is often plated but rarely at fault unless the engine has been over-filled with oil. The two bottom bolts that retain the rear main bearing flange, these go into holes that are not blind and oil can leak up the threads. The cure is to wrap the threads with PTFE tape and use a drop of Loctite 243 on them to seal them. Finally the welch plug that covers the back of the cam bearing is prone to leakage. Clean it thoroughly and seal it with epoxy.

Yes, it could be something more esoteric like a porous case but it is highly unlikely. To perform any of these three fixes requires removal of the gearbox and clutch. To reassemble the clutch you will need the clutch compression tool or an old gearbox input hub to centre the plates and compress the springs.

Hi Pete,
Thanks a lot for your explanatîon.
I'm going to do the finger test to confirm that leak.
Is it possible to remove the gearbox and clutch without removing the engine from the bike?

Hey Matias, mine does this from time to time. To date, I have avoided pulling off the gearbox and clutch. Usually it goes away after an oil change.

Hi Oz,
It's the first time for me in 40 k miles...
It's strange that ir goes away with the oil change...What could cause that?

New thicker oil...

Sadly there is no way to remove the clutch and gearbox without dropping the engine.

Whatever you do don't over fill the engine with oil. Somewhere below the half way mark between the 'Full' and 'Add' marks on the stick with the stick screwed in is as high as it should ever be.

Oz1200Guzzi wrote:

New thicker oil...

Ok, I ser.

Ok, I see...

Pete Roper wrote:

Sadly there is no way to remove the clutch and gearbox without dropping the engine.

Whatever you do don't over fill the engine with oil. Somewhere below the half way mark between the 'Full' and 'Add' marks on the stick with the stick screwed in is as high as it should ever be.

I never went above the Full mark, but I have been close to it.... The engine was consuming a bit of oil (now it seems to have improved...), so sometimes I came close. I use a block of wood under the side stand to check the level and the bike tilts slightly to that side...some safety margin there...
Would this cause a permanent damage to the Seal or will it return to normal when the oil level drops?

Thanks

Pete,
"...with the stick screwed in..."
Can you confirm this? You recomend the oil level to be measured with the stick screwed in?

Correct. Really the best way to do it is pre-fill the filter when you change it and add three litres. Then don't add any more unless it drops off the end of the stick. Big block Guzzis find their own level. No matter where it starts on the stick it will drop to a certain point and then stop using/loosing any. That should be treated as the 'Full' mark. Where that 'Full' mark is will depend on several factors but as long as the motor is not compromised mechanically it will just *use* oil until a certain point and then stop.

On my bike the point at which it stops using it is at the very tip of the stick. At that point the sump contains about three litres including what is in the filter. That's plenty of oil, really.

I have seen mine dropping to the tip of the stick too...It makes me nervous riding the bike like that...below the tip you don't know where you are any more.
I believe as long as the pressure light doesn't come on you should be ok, but I'm allways affraid the sensor can fail too. I already had to replace one...

I had to change a clutch at about 50k Mrs, and the crank seal was leaking slightly. It wasn't too bad - before the tear down it would deposit a drip most days while parked at work.

Just so you know its pretty robust, my Cali 2 got home on 1/2qt in the pan w/no lite & no noises. That might not work on your oil pan, you need a longer stick.

Hi Pete
I just made the finger test. As far as I could reach I just found dust from the clutch...no oil. I guess if there is a leak it must be a small one.
The oil level is at 1/4 from "add" to "full" with the stick sitting on the thread (cold...). To much you will say, right?

Trogladyte wrote:

I had to change a clutch at about 50k Mrs, and the crank seal was leaking slightly. It wasn't too bad - before the tear down it would deposit a drip most days while parked at work.

Hi Trogladyte,

May I ask how much did you had to pay for that repair?

We would probably charge six to eight hours to do a clutch or replace a rear main/fix a leak from the bell housing as everything rearwards of the crank has to come off. Also on a bike this old, unless it has had the swingarm bearings and shock linkage bearings greased I'd be rolling them into the cost though as they will come out in chunks as the swingarm is removed.

Thanks Pete.
Seems an efficient work, considering all that needs to be disassembled and assembled back together.
Regarding the swingarm bearings and links, wouldn't a swingarm in that condition make squeeks and other noises?

No. It would just make the bike handle like your grandmother's vacuum cleaner.

I could not tell....I never rode my grandmother's vacuum cleaner...In fact I'm pretty sure she never had one...
But I don't feel handling issues, and pressing on the seat the suspension seems to have a smooth action...

Mine felt quite smooth even with the linkages shot to pieces.
There is a lot of weight and massive leverage on the suspension linkages.
Almost impossible to feel wear when the bike is together except in shoddy suspension action.
If you get the wheel off the ground you may be able to lift and drop it to feel vertical play