Stage One Kit Fitted
Posted 29 October 2020 - 02:34 PM
Hello,
My Mini has been leaking oil from the timing cover for ages now and its time to get it sorted. I know the engine plate (which the timing cover attached too) isn't great. So looking to replace with a new plate and timing cover.
Just wondering if this is possible with the engine in the car? I know it'll be a pain but not as much of a pain as taking the engine out I guess.
Anyone else done this? Anything to look out for?
Many thanks,
Neil
..is NOT a girl!
Posted 29 October 2020 - 04:04 PM
Can't see it being that hard, but are you sure it's necessary? I can only see it helping if it's leaking past the cover gasket because the screw threads have pulled or there's some obvious damage to the plate.
One Carb Or Two?
Posted 29 October 2020 - 05:20 PM
Back plate replacement is possible with the engine in the car.
It may be the famous Half moon seal between the block and the gearbox casing which is leaking. This is behind the back plate and it may be the source of the leak. Technically the gearbox and block need to be split to replace this one. I don't know if it is possible to replace without splitting the two, have never attempted it myself.
The timing cover has bolts of two different sizes and two different lengths. It's fairly obvious which go where during re-assembly as long as you are looking out for them. If you get them in the wrong place they can push the back plate away from the bock and your nice new gasket.
Camshaft & Stage Two Head
Posted 29 October 2020 - 05:34 PM
Back plate replacement is possible with the engine in the car.
It may be the famous Half moon seal between the block and the gearbox casing which is leaking. This is behind the back plate and it may be the source of the leak. Technically the gearbox and block need to be split to replace this one. I don't know if it is possible to replace without splitting the two, have never attempted it myself.
The timing cover has bolts of two different sizes and two different lengths. It's fairly obvious which go where during re-assembly as long as you are looking out for them. If you get them in the wrong place they can push the back plate away from the bock and your nice new gasket.
The 'hard' half moon seal sold by Minispares was designed to be used as a replacement without splitting the engine/box.
Up Into Fourth
Posted 29 October 2020 - 05:40 PM
You'll also have to take the timing chain and gears off to do the front plate ... 
Crazy About Mini's
Posted 29 October 2020 - 06:29 PM
One Carb Or Two?
Posted 29 October 2020 - 06:45 PM
While the timing chain cover is off, check and see that the attachment holes haven't been 'dimpled' by over tightening the fasteners, a source of a leak from the gasket.
Stage One Kit Fitted
Posted 29 October 2020 - 08:29 PM
Thank for all the replies Guys. Much appreciated. I think im going to try with engine in situ - got a feeling that it'll be the half moon thats leaking. Can this be changed in situ too? anyone done this?
Super Mini Mad
Posted 30 October 2020 - 12:18 PM
Thank for all the replies Guys. Much appreciated. I think im going to try with engine in situ - got a feeling that it'll be the half moon thats leaking. Can this be changed in situ too? anyone done this?
Yes, as above - use the minispares hard hard half moon and it can be installed without splitting the engine from the box. Stick it in some very hot water before installing it, might make is easier.
Crazy About Mini's
Posted 30 October 2020 - 02:35 PM
One Carb Or Two?
Posted 31 October 2020 - 01:16 AM
Buy a UV light. Even without the added dye you'll clearly see the trace of the oil.
Have used dye and UV light with success-simple and effective.
Uncle Cooperman, Voted Mr TMF 2011
Posted 31 October 2020 - 10:44 AM
Before you start, try to see whether the oil is leaking from the timing cover gasket or the half-moon seal. It will make a huge difference to the amount of work. It is most likely the gasket.
As Midas says, it's not a difficult job, but it will take most of a day.
First of all remove the radiator and the fan belt and fan.
Bring the crankshaft to TDC as this will make it easier to re-time the cam if the timing gears have to come off.
It is a really necessary to remove the starter motor in order to lock the flywheel which enables you to undo the bottom pulley bolt. This bolt can be very tight and unless the flywheel is locked you are relying on having the car on the ground with it in gear and the big spanner then just tries to move the car back & forwards.
Once the front pulley is off you can remove the timing cover screws. Check the threads on all of these and replace if they look damaged.
You can now check the front plate's mating surface to the cover. If the plate looks OK and the oil is not leaking from the half-moon seal then just change the timing cover gasket.
If it is the half-moon seal the front plate needs to come off and the sprockets & timing chain are next to be removed.
The 3 bolts holding the cam retaining plate must then be taken out and the plate removed followed by any other plate retaining bolts. Also remove the lower alternator bolt, although it is easier to just take the alternator off. The plate can then be removed.
It is most likely the timing cover gasket. Make sure the timing cover face is level and undamaged. Do not over-tighten the small bolts as that splits the gasket & use a good smear of Blue-Hylomar sealant on both sides of the timing cover gasket. Before finally tightening the timing cover bolts, re-install the front pulley. This ensures that the cover is centered on the pulley shaft.
Whilst doing this it is wise to change the timing chain and, if necessary, the tensioner.
A fairly deep strip at the radiator end gives you a chance to check other things such as fan belt, engine mounting, top & bottom hose, etc.
Use a bit of Loctite on the cam retaining nut and the front pulley bolt when re-assembling. Be careful not to graunch the radiator gills on the fan when re-fitting the rad.
I hope this helps.
Stage One Kit Fitted
Posted 15 November 2020 - 07:28 PM
Stage One Kit Fitted
Posted 15 November 2020 - 07:46 PM
Before you start, try to see whether the oil is leaking from the timing cover gasket or the half-moon seal. It will make a huge difference to the amount of work. It is most likely the gasket.
As Midas says, it's not a difficult job, but it will take most of a day.
First of all remove the radiator and the fan belt and fan.
Bring the crankshaft to TDC as this will make it easier to re-time the cam if the timing gears have to come off.
It is a really necessary to remove the starter motor in order to lock the flywheel which enables you to undo the bottom pulley bolt. This bolt can be very tight and unless the flywheel is locked you are relying on having the car on the ground with it in gear and the big spanner then just tries to move the car back & forwards.
Once the front pulley is off you can remove the timing cover screws. Check the threads on all of these and replace if they look damaged.
You can now check the front plate's mating surface to the cover. If the plate looks OK and the oil is not leaking from the half-moon seal then just change the timing cover gasket.
If it is the half-moon seal the front plate needs to come off and the sprockets & timing chain are next to be removed.
The 3 bolts holding the cam retaining plate must then be taken out and the plate removed followed by any other plate retaining bolts. Also remove the lower alternator bolt, although it is easier to just take the alternator off. The plate can then be removed.
It is most likely the timing cover gasket. Make sure the timing cover face is level and undamaged. Do not over-tighten the small bolts as that splits the gasket & use a good smear of Blue-Hylomar sealant on both sides of the timing cover gasket. Before finally tightening the timing cover bolts, re-install the front pulley. This ensures that the cover is centered on the pulley shaft.
Whilst doing this it is wise to change the timing chain and, if necessary, the tensioner.
A fairly deep strip at the radiator end gives you a chance to check other things such as fan belt, engine mounting, top & bottom hose, etc.
Use a bit of Loctite on the cam retaining nut and the front pulley bolt when re-assembling. Be careful not to graunch the radiator gills on the fan when re-fitting the rad.
I hope this helps.
One Carb Or Two?
Posted 02 June 2023 - 05:53 PM
Having read the above posts I have decided to change the half moon seal as it has been leaking for a while, I am halfway through the works and have 2 questions :
1: Should I use any sealant on the half moon seal, and if so what type ?
2: I curently have a 20mm spacer on the cooling fan, when I purchased new bolts from Minispares they will only fit without the spacer being fitted, is this required, and will this affect cooling?
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