Lemans 2 Oil seep gearbox thrust piece

Does nay one else have experience of the O ring on the thrust piece letting through a small amount of oil. I thought I had sorted it with a small wrapping of PTFE under the seal in the groove hoping that this would expand the seal and make a tighter fit but seep is back. Is this O ring the only line of seal around the push rod and thrust piece components?

yes , try new o’ring.Â

It seems the obvious step but it was fitted as new by a reputable mechanic less than 500 miles ago when the gearbox was over hauled and leaked almost immediately. But yes your right in order to rule it out. Could be simple oversight. Thanks Â

I presume hole in casing is OK, no damage causing oil to leak past the O-ring?

Couldn’t  see any scoring but will take a closer look. I assume that this is the only seal holding back the oil then.Â


Well it is on mine!

Does seem like O-ring has gone hard or some has worn off ~ makes me wonder if it actually was renewed but is still the old one.

Sadly I think this is a wheel off, swing arm off job in order to get the plunger out.Â