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Discussion Starter #1
How about drilling the K1200LT clutch bell housing (6 O'clock position)? Many dry clutch housings are cast with a vent hole at the bottom and to my recollection cars, trucks and tractors have been this way for over 60 or 70 years or more. In our situation the engines rear main bearing seal failure and/ or worse the transmission input bearing seal failure can quickly wipe out a dry clutch disk just like a failed seal of a "non-drilled" clutch slave cylinder of a K1200LT. My K1100LT has a very similar engine, clutch (mech. actuated) and transmission and is OEM vented at the bottom of the bell housing. Should you suffer a seaping engine rear main bearing seal or seaping transmission input shaft seal you will see that engine oil or transmission gear lube appear at that bell housing port. The advantage would be a much earlier "heads up", bad things are about to happen and give you some options............. to get to a dealer or get out the "anonymous book" rather than getting the first signal of "high rpm" and "no matching go". Granted this is not a case where the oil has trapped withing the housing and is freely be flung about because it takes very little oil to do the damage but the slow seaper is the issue and knowing early that is doing that. In reading the mail I see so many have been "on the road" and have had great trips screwed up where another drilled port could perhaps provided an "early warning"! :eek: Would appreciate the great "sage" advice so freely provided here on K12LT.

This may have shown up before but I couldn't find it.
 

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Bell housing vent

Tourdog said:
How about drilling the K1200LT clutch bell housing (6 O'clock position)? ....

I don't think this would help with respect the clutch seal failure. In that case I think the fluid runs down the clutch throw-out shaft to the center of the clutch. The clutch probably gets fouled before there is any fluid build up in the bottom of the bell housing.
 

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There is enough clearance in the gap to allow seepage to show, but the problem is that if the transmission input shaft seal or clutch slave cylinder seal goes the clutch is contaminated long before enough fluid has leaked to make it to the bottom of the intermediate housing.

The rear engine seal will show there though, as engine oil is slung out all around the housing by the clutch drive plate, and will run around and down the sides of the housing to the bottom, where it will seep out.
 

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Tourdog said:
How about drilling the K1200LT clutch bell housing (6 O'clock position)? Many dry clutch housings are cast with a vent hole at the bottom and to my recollection cars, trucks and tractors have been this way for over 60 or 70 years or more. In our situation the engines rear main bearing seal failure and/ or worse the transmission input bearing seal failure can quickly wipe out a dry clutch disk just like a failed seal of a "non-drilled" clutch slave cylinder of a K1200LT. My K1100LT has a very similar engine, clutch (mech. actuated) and transmission and is OEM vented at the bottom of the bell housing. Should you suffer a seaping engine rear main bearing seal or seaping transmission input shaft seal you will see that engine oil or transmission gear lube appear at that bell housing port. The advantage would be a much earlier "heads up", bad things are about to happen and give you some options............. to get to a dealer or get out the "anonymous book" rather than getting the first signal of "high rpm" and "no matching go". Granted this is not a case where the oil has trapped withing the housing and is freely be flung about because it takes very little oil to do the damage but the slow seaper is the issue and knowing early that is doing that. In reading the mail I see so many have been "on the road" and have had great trips screwed up where another drilled port could perhaps provided an "early warning"! :eek: Would appreciate the great "sage" advice so freely provided here on K12LT.

This may have shown up before but I couldn't find it.
Not a bad idea but,,, Take a look at the bottom of my motor trans junction. Looks nasty ,thats motor oil due to rear main Oring failure. My slave cylinder started to leak as well. My clutch was not slipping at 72,000.
 

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hoodoodrum said:
In the first picture, is that center nut with the red on it the other end the clutch slave rod pushes up against?
That nut secures the clutch housing. The clutch pushrod pushes on the diafram spring.
 

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Discussion Starter #7
Couple notes: The drilled port I am talking about is in addition to the one required to vent the clutch slave cylinder should its seal fail. I should think any quicker way for extraneous engine oil and or gear lube to get spotted by the m/c operator would be a definite advantage. Venting a bell housing is a very easy task and in no way did I mean to obviate the excellent idea to vent the barrel of the clutch slave cylinder!
As always excellent viewpoints! Thanks! :)
 

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Tourdog said:
Couple notes: The drilled port I am talking about is in addition to the one required to vent the clutch slave cylinder should its seal fail. I should think any quicker way for extraneous engine oil and or gear lube to get spotted by the m/c operator would be a definite advantage. Venting a bell housing is a very easy task and in no way did I mean to obviate the excellent idea to vent the barrel of the clutch slave cylinder!
As always excellent viewpoints! Thanks! :)
I knew what you were talking about, but the case to block fit is not sealed, and anything leaking down to the bottom will leak out without adding any holes. It is no where near a liquid tight seal where the housings meet.
 
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