This innocent looking axle box oil filler cap is one example (right front).
|Filler cap with original fitting (1)|
|Filler cap with original fitting (2)|
Three of the axle box pots are like this and leak whereas a fourth one (right rear) which doesn't leak has the bracket rotating around its pin firmly fitted in its 'pot holes'.
I decided it would be prudent to convert the pins to threaded short pins which should prevent further leakage.
In advance, I made these short pins about 18mm long, 8mm in diameter with an M8 thread. The original pin diameter was about 1/4" so M8 was an ideal size.
|M8 Short pins|
|Short pins with adapted lid bracket|
I've topped up the oil level to where it would have leaked previously. Fingers crossed it will be successful.
|Level topped up above the new pins.|
One small point that I'd been mystified by for some time is whether the axle boxes use a pad to 'wick' the oil to the bearing surface or the bearing simply dips into the oil bath. I found an old photo from when I was making a new axle box cover gasket. It clearly shows a pad beneath the bearing.
|Axle bearing showing oil pad|