411 front suspension lower ball joint grease nipple

[Kevin H]

Do other 411 owners have a grease nipple on the front suspension lower ball joint?

And does anyone know what the thread is?

When we disassembled the front suspension only one of the grease nipples was in place, except it wasn't the correct one and was held in with silicone sealant! (on the other side there was just a hole).

We have tried all common imperial threads and metric and drawn a blank.