I'm fixing an oil leak on my classic Mini and I have a question. I have a rod change gearbox and the leak is from the selector shaft. I've removed the roll pin on the coupling and pulled the old seal out. I was planning on fitting the 3 piece kit (aluminum collar to locate the shaft, new oil seal, and rubber bellows to keep road debris away), but it looks like there is already an aluminum locating collar in place on my car's gearbox. In fact, I can't remove that collar - there is nothing on it to allow me to hook it and pull it out. So... on one hand, it looks like the collar's O-ring must be in good shape and holding it in place, but on the other hand I'd like to install the brand new collar just to be on the safe side since I'm this far in. Any thoughts?