TOPIC:

I’ve changed this seal twice now and it keeps failing again shortly after. I’ve also changed the bearing in the outer cover as I wanted to eliminate that possibility. Could there be something inside the engine that is causing this seal to fail?
I am losing a lot of oil whilst I’m riding,there’s just drops underneath in the morning.
Thanks.

Does the push rod surface have any scratches or scoring marks?
Or do you have maybe put the seal with the inside out.
Some pics would help.

The gearchange lever is clean,it’s got some movement when the outer case is off but seems fine when it’s on and as I said it’s fine for a couple of days then gets bad pretty fast. I can’t do a pic at the moment as it’s a girls from the club that I look after for her. Next time she’s round I’ll post one.
I put the seal in with the metal shield outside,so It drives in evenly with a piece of conduit tube,if that makes sense(and iirc)
I was wondering if it might help to put some heatshrink on the shaft?
I put it in the same way as the pic.

Are you sure that you drove it all the way in?

Yes,it’s in level with the casing. You can only go so far or you’ll have gone too far.

Does the gear change shaft have much sideways play? if you put the shift lever on the shaft and push down like you would when changing gears, does the shaft move down or does it just twist? There should be minimal movement, just a twisting motion.

I've seen this issue on rod change gearboxes in cars where the sideways movement can damage the seals and they start leaking. Any excess movement in this case would indicate that the shaft has worn a larger hole in the case, or that the bike has been dropped on the lever and cracked the case. I've never seen this happen on a bike without visible damage from dropping the bike, but check the movement to rule it out.

Irish Yobbo wrote: Does the gear change shaft have much sideways play? if you put the shift lever on the shaft and push down like you would when changing gears, does the shaft move down or does it just twist? There should be minimal movement, just a twisting motion.

I've seen this issue on rod change gearboxes in cars where the sideways movement can damage the seals and they start leaking. Any excess movement in this case would indicate that the shaft has worn a larger hole in the case, or that the bike has been dropped on the lever and cracked the case. I've never seen this happen on a bike without visible damage from dropping the bike, but check the movement to rule it out.

But wouldnt the outer cover prevent the shaft from moving about enough to knacker the seal on the inner case? Whats on the outer casing anyway,I dont remember. Is it another seal,a bushing or a felt ring??

It’s a bush,there’s really not a lot of movement when changing gear,you would think a new seal would do the trick.

You say you are fitting as per your picture. The picture shows the outside face. You are definitely fitting the seal the correct way round?

Pipes66 wrote: ... I can’t do a pic at the moment as it’s a girls from the club that I look after for her. ...

Not sure, then, what bike you're working on if it's not the one in your sig line.

Assuming it's the shift shaft in question and not the clutch pushrod:
On Z1's there is significant slop in the shift shaft if the outer sprocket cover is not in place, as the bushing in the outer cover provides significant support at the outer end of the shift shaft. An unsupported shift shaft will appear to be quite loose & sloppy.

Are you protecting the inner lip of the seal from the sharp points of the shift shaft splines when you slide the seal over the shift shaft?
On Z1's, when the tranny cover is installed, the shift shaft seal has to slide over the outer splines of the shift shaft. We always wrap one layer of electrical tape (or 2 ~ 3 layers of teflon tape) around the splines so they don't damage the relatively delicate lip of the shift shaft seal.

Good Ridin'
slmjim & Z1BEBE

Yes I protect the seal. I wouldn’t say the shaft was over sloppy at all,there is some movement but it’s not excessive. I suppose my question is could the movement/sloppiness be at the crankcase end of the shaft rather than 5he outer casing?

There are three seals. Two in the sprocket cover and one in the tranny cover. In the sprocket cover one faces out and the inside one faces in. They provide support for the shaft.
Steve