Topic: Need help on an oil seal!

[Bakeoff]

I'm doing a little refreshing on my 74 cb550 motor and ran into a few things.  With the front sprocket cover removed, it was very obvious that a chain had broken at some point.  The case is hacked, but nothing that will cause any issues.

The problem I'm having is with the oil seal (about 1.25" in diameter) just forward of the sprocket.  The chain hit it and it has a small slice in it.  So, I have two things I need help with:

1. I can't find the damn seal on any of the online sites.  I've checked bike bandit and a few others, but I can't find the seal in any of the diagrams.

2. Can that plug be removed without splitting the cases?  I'd like to avoid splitting them since I was only ripping it down to replace leaky head pucks, which I need to source too.

Any help would be huge!

[bryanj]

Thats not a seal its a plug
To replace it you have to split the cases
last i heard it had been obsoleted
try westernhillshonda
part number 91207-374-000

[Bakeoff]

I take it, its flanged on the back?

I should probably also replace the seal on the shifter rod, but I can't find that one either.

[Duanob]

http://www.powerpartsplus.com/OemParts#%2fHonda%2fCB550F_A__MOTORCYCLE%2c_JPN%2c_VIN%23_CB550F-1109886%2fTRANSMISSION

Part number 39, seems like they have it in stock.

[strynboen]

hey mine have also that slice ..but så long it are tight and not leak.. dont fix it..the plug and seal have some "dots" who fits in block..so they can not be thanged witaut to split the block..have tryed to remove some on my 400 four..but tjek that 550 are same way..have not have open the blok on my 550..

[Bakeoff]

Thanks guys!  At least I know its available!  Mine currently has a small slice in it and I found oil in the chain cover when I removed it. 

[strynboen]

normal kome that oil  leak from pump.. try to klean  all up..and make an test run

[Hannibal Smith]

As posted above, it might not be leaking. That plug has a steel disc molded into the "plug" to give it rigidity, and it has to be worn pretty bad to start leaking. I would definitely clean that whole area up with some Simple Green (etc.) and then find out if it really is the culprit.
My old 550 motor before the rebuild was leaking from the pump or the shifter shaft, even though it looked like it was coming from that "plug"..................make sure!

[domer]

make sure its you have the right size chain on there too.... too big of a chain will leave that mark.

[Bakeoff]

Like I said in the first post, the previous owner had a chain break at some point.  There is damage to the case and the sprocket cover that makes this very obvious.  The plug itself has some of the rubber coating peeling back and there is a visible slice in the metal of the plug.

That said, I know the shifter seal is also leaking.  The Oil pump was clean, but I replaced o-rings on that yesterday.

I was just asking if I could replace it without splitting the cases.  No worries guys.  I'm good.

[Fritz]

Hi Bakeoff,
 
 I'd say 'maybe' the seal can be replaced without splitting the cases. It does not have any ridge or groove in it that could prevent it from being pushed in. Might be difficult to hammer it in without hurting the rubber coating though.
 
 Here are some pics showing the damage. On the third picture you can see a dent in the metal cup on the left side that indicates that the metal is quite weak here. If it gets rubbed through, oil will weep out.
 Since the transmission main shaft is not pressure lubed, this leak might be fixed with sealant without the need to replace the seal.
 But the correct way to change this seal is during a rebuilt of the bottom end, including splitting the cases and exchanging all seals. Here's one source four this seal:
 http://www.cmsnl.com/products/oil-seal-kitcb550k_90000374000/
 It conveniently comes along with all other seals required to seal the shafts in the bottom end for the next ten to twenty years.
 
 Good luck
 Carsten