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dave griffiths
dave griffiths's picture
Last seen: 3 hours 50 min ago
Joined: 29/12/2020
Oil leak

Hello everyone

My K series engine has developed an oil leak from the bell housing which I guess is from the crank oil seal.(looks like engine oil, not gear box). Will this have to be an engine out job or is there a simpler way to access it.

Dave G 


SM25T's picture
Last seen: 2 hours 13 min ago
Joined: 17/04/2014
Engine out.
SM25T's picture
Last seen: 2 hours 13 min ago
Joined: 17/04/2014
Check it isn't running along block from above first.
7SW's picture
Last seen: 7 hours 37 min ago
Joined: 07/11/2015


Try first to check with an endoscope if the bell housing is contaminated with oil.

You can also make a little hole at the bottom of the bell housing for letting the oil leak through as described there:


But, as SM25T wrote, oil make come from another place.

Rear camshaft seal may also leak; in this case oil is running along letting thinking that oil is coming from bell housing.

Last seen: 3 hours 4 min ago
Joined: 17/04/2014

If you are replacing the rear seal, make sure you get a decent quality one, there are plenty of rear seals available cheaply that are the wrong material and will harden and leak fairly quickly, there are others which are dimensionally unsound. Make sure you cement the new seal in using a suitable silicone sealant on the flat flange, clean the flange of any residues and then use carb cleaner or isopropyl alcohol to make sure it is chemical clean, clamp in the new seal for a few hours to ensure the sealant has cured. It's a job you will *not* want to do again.


sforshaw's picture
Last seen: 1 min 30 sec ago
Joined: 17/04/2014

The sealant you need is "RTV" (Room Temperature Vulcanising), plenty of different ones available.


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Wrightpayne's picture
Last seen: 2 hours 10 min ago
Joined: 17/04/2014

I recently used some loctite 5980 from Halfords recently for a different oil sealing job. Its described as gasket maker. It sets very differently to bathroom sealant - its much harder / denser.

One sealing task was where the selector rod comes out of the front case of the gearbox, basically sealing between the front of the maincase and bell housing. 

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