rear crank seal

[Pascal]

Hi,

Moggy's leaking lots of oil and my favourite mechanic recommended to replace the rear crank seal and sump gasket.

I've looked at ESM and found only what they call a conversion kit:

http://morrisminorspares.co.uk/shop/pro ... cc6f861fc3

Bull Motif sells the same. Is this what I need? How does it work compared to the original seal?

Regards

[aupickup]

they are not easy to fit, a certain amount of machining is required i beleive

have you checked all the breathing system

[mike.perry]

If the crankcase breather system is not clear and working properly excess pressure will build up and force oil past the oil throw on the rear of the crankshaft. This is particularly important on the 1275 engine. A new crank seal would be part of the sump gasket set.

[Pascal]

Some time ago I put a new hose between the green cylinder and the carburettor but it didn't make any difference. The green cylinder looks full of mesh. Should I try to clean it? How?



Regards

[aupickup]

i think pascal is referring to the owen burton rear crank oil seal conversion which really is not the answer to his problem, they are exoensive and in a lot of cases do not work

[bmcecosse]

There is NO rear crank seal - it is a simple scroll with labyrinths which trys to pass any oil back into the sump. If there is internal crankcase pressure - it can't cope. Hot engine at idle speed - take the oil filler cap off. If there is a plume of smoke/fume - there's the problem. The engine needs an overhaul - at least new piston rings. Can't see where your green hose goes - does it go straight into the carb, or does it go into the air filter casing ? If casing - it will just be covering the paper filter in oily gunge - completely mad system. If into the carb (copper colour pipe on right side of carb) then assuming it's not blocked - that will deal with reasonable fume - but if excessive it just can't cope. The 'mesh' in the green canister can only be cleaned aftyer you remove the cam follower cover. Then either flush it out with paraffin or petrol (care) - or set it on fire. But I doubt it's blocked!

[PSL184]

The hose looks to be contaminating the air filter to me

[bmcecosse]

Yes - I know !! It is (just) possible to cut a hole in the aluminium mounting bracket for that filter - and put the hose in there so the fume is drawn directly into the carb, rather than splattering all over the filter.

[PSL184]

Might be an idea to try it with a vented rocker cover also....

[aupickup]

[quote="bmcecosse"]There is NO rear crank seal - it is a simple scroll

yes roy we know

i was saying that the owen burton kit is called a rear oil crank seal

[Pascal]

I've double-checked and the only place the hose can go carb side is to a tube welded to the base of the air filter casing. I've checked the paper filter and it's clean, no oil there. The set up looks reasonalby standard, there is no evidence of tinkering. My moggy is from 1970 so could that be the way it was on the last ones? If that's the way they came out of the factory I guess it should work, assuming nothing is blocked.

Can anybody with a 1970 moggy comment on the breather set up?

I'll check the smoke from the rocker cover but the engine is running perfectly well.

Regards

[aupickup]

mine is a 69 model and has the breather from the rocker cover to the air filter housing

then the tappet cgest cover to the air

[Peetee]

I though the crank was leaking at the rear and found instead that it was the cover on the oil pump. Just to be on the safe side I also poured some parafin into the crankcase breather pod when I did an oil change.

[Pascal]

mine is a 69 model and has the breather from the rocker cover to the air filter housing then the tappet cgest cover to the air

So you have two hoses going to the air filter housing? Can you sent a picture when you get a chance?

Regards

[aupickup]

the tappet chest cover has a pipe that points down by the side of the engine block TO AIR

[bmcecosse]

Just one breather to air filter (which is crazy) - and then later carbs have an inlet on the side where the breather can be connected, The cam follower cover can then be left open to air - so there is a flow of air through the engine, which helps to keep it clear of moisture, and hence reduces 'Mayo' build up in the rocker cover. I have no idea why BMC decided to do away with the breather connection on the rocker cover - it was a god-send! These older covers with breathers are becoming hard to find now - although I know a Mini spares place had a huge carton of them a couple of years ago and they were selling well at a Mini event!
Dennis - the comment re 'no rear oil seal' was for the original poster, who said there was oil leaking from the rear seal! There isn't one - just a small gap - and any pressure in the engine WILL force oil out of there. Only other explanation is a seriously worn rear main bearing - and the scroll can then be overwhelmed with large volumes of oil coming out of the bearing!

[Declan_Burns]

Pascal,
Mine leaked everywhere when I first got it. Before you even consider fitting the Owen Burton seal, try running the engine with the car over a pit, having cleaned off all the oil and grud beforehand (and get out your old rain hat). You really have to locate the actual source of your oil leak(s). This is very important as oil leaks can be very deceiving so you really need to see where it's coming out. The rear crank seal retrofit is a lot of work although it worked well on mine up to now. If you have to replace the sump gaskets, which in my case was the major culprit, I would recommend using the spridget 1275cc synthetic rubber seals instead of the cork seals. They have to be cut down to size. This worked for me as I tried cork several times without success. Thoroughly clean and degrease all surfaces and as an added precaution, use high temperature silicon allround allowing it to cure properly before starting the engine. Check also if the engine has tappet chests. Again could be cork but there are modern neoprene seals available. Otherwise as above.
Hope it helps.

[jonathon]

http://jlhmorrisminors.co.uk/images/mae ... stro_1.jpg


If its the crank oil seal then this is your best bet. Forget the OB version as it relies too heavily on the condition and size of the end of the crank.
Sorry moderators pic was supposed to appear rather than site link.Please change if need be )
Plus this mod is only available for 1275cc based motors.

[Declan_Burns]

Jonathon,
Looks interesting. Is that something new? Any infos?