These photos are from a 1964 MG 1300, but they use the ubiquitous 1100/1300 engine with gearbox in the sump power-plant that was installed in MILLIONS of cars back in the 70's through to the 90's when classic mini production finally ceased.
Check these photos out:
The car was brought to me and my chum, as we have done quite a lot of work on the old BMC/BLMC cars that have these power-plants in them.
The car was EXTREMLY noisy in the gearbox, and was leaking a large amount of oil.
When they put the engine back onto the gearbox, they used a home-made gasket between the engine/box and the clutch housing(they admitted that), and that is a BIG no-no, as the correct gaskets are thick by design, and you torque them down while measuring the end-float on the intermediate gear and it's thrust washers to make sure everything is good. Putting a home-made gasket on, made out of thin gasket cardboard means the clearances are all screwed up, and this is the end result - which is
not good.....
It basically just rubbed itself to bits, with metal debris eventually getting picked up by the drop-gear arrangement, and blowing teeth of the intermediate gear, and knocking a large hole right through the clutch cover housing!
Ouch!
Note that we have not even FOUND the remains of the needle-roller bearing that normally lives in the cover housing, and only a slim amount of the outside of the cage of the bearing shell remains! Yikes....
Because of all the metal shavings etc, this engine and gearbox will have to be totally stripped and cleaned, to make sure there are no metal filings left to cause more damage, so it is gonna cost them a few bob!
Moral of the story: Use the correct gaskets, and don't cut your own unless you HAVE to. The after-market housing gasket is easy to get, and only costs about $15 or so, and cos they did not want to spend $15.......well...it's not going to be a $15 repair job, I can tell you that much!
Smoke makes things work. When the smoke gets out, it stops!