hub oil leaks
Posted: Wed Aug 29, 2018 10:07 pm
I was on another forum this evening and there was a post about oil leaking from the hub and that even after several attempts and several Oil seals three worked, but one continues to leak. They then went on to mention that they couldn't find where to put the "o" ring that is shown in the parts book. I will be the first to mention that some of the design "choices" made by the Haflinger designer - I doubt it was completely one person design for every part, are not the simplest or probably even the best way to deal with a particular issue.
Case in point is the way in which the hubs are designed and the preload on the bearings done.
Be that as it may, on with the reason for this post. I wrote the following for the poster to follow and hopefully solve his oil leak issue.
You are not the first to run into this problem, nor will you be the last..
Anyway, it's easy!
When you have dismantled the hub which i am sure you can do blindfolded by now!
Hold the hub flange (the bit with the studs to hold the wheels) in a vice by the studs. Use a blowtorch to heat the ring on which the oil seals inner diameter runs on.
After a short while - i.e. not a lot amount of heat, it should start smoking and "pop" it will suddenly lift itself off the back of the hub!
Basically, under that ring is where the "o" ring fits and heating the ring causes the "o"ring ro expand and push the ring away giving you an access gap to lever it off if it doesn't want to just slide off.
Clean up surfaces. Put a little bit of red rubber grease on a new "o" ring, put it on the shaft. Put the metal ring on and using a suitable piece of tubing, tap it up against the side of the hub flange and then reassemble the hub.
Take special care with setting the bearing preload using the appropriate shims as it has a huge impact on the amount of friction that saps power if you get it too tight and will leak oil if you get it too loose.
You can make yourself a tool for checking the bearing preload by getting a piece of wood or metal with two holes to fit two of the wheel hub studs and which sticks beyond the hub flange on one side. Make a notch in the tool which is 9 cm from the axle centre. Hang a 1kg bag of sugar on a piece of string from here. The arm should stay in a horizontal position if left to itself, but should require very little extra force to make it swing down.
Post back if you need more explanation / detail etc.
John
Case in point is the way in which the hubs are designed and the preload on the bearings done.
Be that as it may, on with the reason for this post. I wrote the following for the poster to follow and hopefully solve his oil leak issue.
You are not the first to run into this problem, nor will you be the last..
Anyway, it's easy!
When you have dismantled the hub which i am sure you can do blindfolded by now!
Hold the hub flange (the bit with the studs to hold the wheels) in a vice by the studs. Use a blowtorch to heat the ring on which the oil seals inner diameter runs on.
After a short while - i.e. not a lot amount of heat, it should start smoking and "pop" it will suddenly lift itself off the back of the hub!
Basically, under that ring is where the "o" ring fits and heating the ring causes the "o"ring ro expand and push the ring away giving you an access gap to lever it off if it doesn't want to just slide off.
Clean up surfaces. Put a little bit of red rubber grease on a new "o" ring, put it on the shaft. Put the metal ring on and using a suitable piece of tubing, tap it up against the side of the hub flange and then reassemble the hub.
Take special care with setting the bearing preload using the appropriate shims as it has a huge impact on the amount of friction that saps power if you get it too tight and will leak oil if you get it too loose.
You can make yourself a tool for checking the bearing preload by getting a piece of wood or metal with two holes to fit two of the wheel hub studs and which sticks beyond the hub flange on one side. Make a notch in the tool which is 9 cm from the axle centre. Hang a 1kg bag of sugar on a piece of string from here. The arm should stay in a horizontal position if left to itself, but should require very little extra force to make it swing down.
Post back if you need more explanation / detail etc.
John