I know, it is supposed to leak After riding I have oil dripping from the detent plunger nut on the transmission. I have, replaced the nut and o-ring, but still get oil on the ground, dropping from the nut. It appears the oil is coming from higher on the front of the transmission. Is it possible the oil is dripping down from the neutral switch or spindle bolt? I thought both of these would be above the oil level line and therefore not prone to leak. Can I remove the spindle bolt to replace the o-ring with out disturbing anything inside the transmission?

I just took a closer look at the front of the transmission and I think I may have identified where the oil is escaping. I have a MK III. Directly behind the shift shaft that runs across the front exterior of the transmission, there is a washer on what appears to be some type of shaft held in by a cir-clip. There appears to be oil escaping from behind the washer. It then drips down the front of the transmission and drops of the bottom of the detent plunger nut. I can't identify it from the parts manual, so I don't know what it is, or what is behind it. Any thoughts?

calbigbird wrote:I have a MK III. Directly behind the shift shaft that runs across the front exterior of the transmission, there is a washer on what appears to be some type of shaft held in by a cir-clip.

That should be the gearchange quadrant, washer and circlip:
http://www.nortonmotors.de/ANIL/Norton% ... 07&Part=21 Parts [21],[22] & [23].

Thanks L.A.B. Is that changable without disassembling the trans or removing it from the frame?

calbigbird wrote:Is that changable without disassembling the trans or removing it from the frame?

There's probably an O-ring behind the washer which needs changing, and it can be done in situ, although it's not all that easy.

Here's a recent thread on the same subject: post45263.html#p45263

(Note that the pre-MkIII quadrants are retained by a bolt, and not a circlip)

Thanks for the link. The problem however, appears to be on the shaft to the left and above the quadrant bold. The the picture at the end of the post appears to have a bolt, mine definately has a snap ring. In the parts manual I do not see an o-ring, but that appears to be where I am losing fluid. Just noticed you said he pre MK III had a bold not a circlip

calbigbird wrote:The problem however, appears to be on the shaft to the left and above the quadrant bold. The the picture at the end of the post appears to have a bolt, mine definately has a snap ring. In the parts manual I do not see an o-ring, but that appears to be where I am losing fluid. Just noticed you said he pre MK III had a bold not a circlip

Yes, it was the quadrant spindle that I was referring to, which has the circlip/snap ring (MkIII type). The camplate is fixed by a bolt on all models. The MkIII parts book doesn't show an O-ring, but if I remember correctly there should be an identical O-ring on both the quadrant and camplate spindle?
However if the quadrant spindle feels sloppy, then the bush may also need changing, in which case the gearbox will have to be removed to fit a new one?

Thanks L.A.B. I just had a lay shaft bearing replaced a couple months ago. He also replaced a couple bushings and 2nd gear, so I would hope he checked the bushing you were talking about. I may take it back to him. If I can stop that leak, it will be almost dry when I park it. Right now, I get some kins of oil dripping off the right side of the swing arm, and this pesky leak dripping from the detent plunger nut. Thanks again for the info.

Regarding the oil leak around the right side of the swing arm, I had the same issue, turned out to be the oil tank leaking from the rear banjos and down
the oil lines and dripping on the swing arm............maybe check and tighten the line fittings?