Topic: Shift shaft seal (say that three times, fast)

[Scott S]

 '71 CB500
  It appears that the minor drip from the left side cover IS the shift shaft seal. It's definitely NOT the clutch pushrod seal. I can't see all the way around the sprocket, but it doesn't appear to be the output shaft, either.


 I searched for a "how-to" on replacing this and didn't come up with much. Is it as simple as pulling the old one out and pushing the new one in? How likely am I to damage the new one? (In other words, should I order two or three, just in case?)
 I'm done similar stuff on my XS650 and I usually chamfer the edge of the hole with a pocket knife. Is that necessary on a CB500? I also use a deep socket to drive the seal in evenly, but the shift shaft seems too long for a socket on the CB.
 I'd like to hear from anyone who's done this, the degree of difficulty and any tips/tricks you may have.

[HondaMan]

Normally, you must remove the shaft to replace the seal, which means more taking apart.
I have seen posts where someone was attempting the crochet-hook removal approach, but haven't heard much success. The steel ring in the OD of these seals are pretty stiff, so trying to pull the seal out by the rubber usually results in the ring being left behind.

[Scott S]

 And how is the shaft removed?

[HondaMan]

And how is the shaft removed?

You have to pull off the right side engine cover and pull it out that side. So, you'll need a gasket, just to change the seal...and more oil... 

[Scott S]

 Well, it just has break-in oil in it right now, so an oil change is coming up. The gasket on the right side is new as of a few weeks ago. Maybe I can get lucky and save it?

 Surely it can't be as simple as just "pull out" the shaft, can it?

[Scott S]

 OK, reading the tech manuals, I see that the clutch basket has to come out. But looking at page 25 of the instructions, how many of these steps are needed to just slide out the shift shaft?
 It appears they continue on to remove much more stuff than I would need to.....or do they?
http://data.sohc4.net/SM500/HSM500550_2.pdf

[TwoTired]

You do NOT have to remove that shaft.  There have been prior threads on this in the past.  It is actually quite easy to remove, but, it does get destroyed in the process and can't be reused.

I use an old, narrow, straight slot screwdriver almost like a tiny chisel. Drive it through the seal about 1/16" from the outer edge (pierces the metal "L" band inside the rubber) and pry it out.  It's never given much argument with this method.  Pops out in seconds.

Access is greatly improved if you remove the front sprocket.

The shaft splines tend to nick the new seal inner lip during installation.  A wrap of scotch tape helps avoid that.

Cheers,

[Scott S]

 Well, that's good to hear. I don't care if I destroy the seal; it's leaking anyway, right?
 I searched for threads on this and found nothing. How do you put it back in? Does it pop in easily or do I need a piece of PVC pipe or something to tap it in?

[TwoTired]

Tap it back in with a socket, pipe, or tubing. The same steel "L" that you pierce it the same "ledge" that you push on for seating.

Pick something that will just fit inside the case hole, but will still rest on the outer edge of the new seal.

You searched for "shifter seal" in the SOHC/4 Bikes forum and found nothing?

Cheers,

[Scott S]

 I searched for "shifter shaft seal", "shift shaft seal"  and, at your suggestion, "shifter seal". The last one only brings up your latest reply.

 I swear I use the search function here. I get a lot of threads asking the same question(s) but no answers. VERY often, there are links in the threads that are dead or pics that are deleted.
 As above, I get LOTS of threads with the word "shifter" in them that have nothing to do with the query. Or the word "seal" that's being used in engine case sealing, etc.

 I'll order two seals as they're cheap. I'll remove the drive sprocket and give it a shot. And I'll take pics and post a "this is how I did it" thread so others may see. 

[Scott S]

 Oh, and not to be stupid, but does the oil need to be drained to do this? Is it below the shaft when the bike is on the centerstand?
 I'd like to keep the break-in oil in there a bit longer if i can.

[bollingball]

Has the chain came in contact with that shaft?

[TwoTired]

Oh, and not to be stupid, but does the oil need to be drained to do this?

No.  But, I have only done them while on the center stand.

[Scott S]

Has the chain came in contact with that shaft?

 Not that I can see....

[HondaMan]

You do NOT have to remove that shaft.  There have been prior threads on this in the past.  It is actually quite easy to remove, but, it does get destroyed in the process and can't be reused.

I use an old, narrow, straight slot screwdriver almost like a tiny chisel. Drive it through the seal about 1/16" from the outer edge (pierces the metal "L" band inside the rubber) and pry it out.  It's never given much argument with this method.  Pops out in seconds.

Access is greatly improved if you remove the front sprocket.

The shaft splines tend to nick the new seal inner lip during installation.  A wrap of scotch tape helps avoid that.

Cheers,

Cool, thanks, TT! I'll try that next. There's a 550 coming over here this month, needs that seal. Last time I tried it (crochet hook method, in another post, 2006?) on a 500, the seal just came apart and left the band inside. It didn't have the metal "L" shape you're describing, though: it was just a rubber walled seal with a flat ring. I finally had to remove the shaft to get it out.

[vames]

Just be careful and you can pull it out. I did one a few years ago and it was easier than I thought it would be. I sunk two small wood screws into the old seal at 180-degrees, put some vice grips on either one, then gently rocked it out. Pushed in the new one with a piece of 1/2" PVC pipe and a rubber mallet.

Also -- I didn't even have to order a new one from Honda. I got the specs that were printed on the old one and brought it to a bearing and seal shop and got them for a few bucks a piece. The guy who bought the bike off me is still riding it around with no leak.

http://forums.sohc4.net/index.php?topic=8287.0