Topic: 1978 cb 550k primary shaft bearing

[markk]

I pulled the primary shaft bearing looking for a crack in the case.

The good news, no crack. the bad news, I am having trouble getting the bearing to seat back into the case.

I have the case halves back together, which makes it more difficult to get the bearing in straight.

Any suggestions? How about heating the case or freezing the bearing?

thanks,

Mark

[dave500]

the primary shaft and its bearings can be removed without splitting the case,just be sure it goes back through squarely,you have the oil pump removed?

[markk]

Yes.

[dave500]

itll go back in after a bit of wrangling,just needs to be squared up,the primary chain tension can cause it to be a bit of a fiddle.

[DaveBarbier]

I replaced my bearing in my '78 550 last month. Froze the bearing and used a heat gun on the case. It didn't slide in but I used a large socket on a long extension and a wooden hammer to gently tap it in. Using science helps tremendously.

If I remember correctly the bearing actually sits a little proud compared to the case wall. So if it isn't completely flush don't go reigning hell upon it or you could actually crack the case. You could probably measure the depth of the bearing hole compared to the bearing thickness to double check this.


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1978 Honda CB550K

[markk]

Thanks Dave,

Your response is very helpful.

Did you have the case on its side or upside down?

Mark

[DaveBarbier]

No problem at all. I had the case on it's side with the front hanging off my bench so the left sprocket side of the case sat square.


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1978 Honda CB550K

[markk]

hello Dave,

I got the bearing in using your method.  The bearing sits .012" higher than the case.

I can't seem to get the primary drive assembly and the starter gear in the case at the same time.

I have tried putting the primary drive assembly in first and then trying to put the starter gear in and then i tried putting the two pieces together and fitting it in. Also with no luck.

What am I doing wrong?

Thanks for your help,

mark

[DaveBarbier]

First, I'd ask what's preventing you from putting it in? Are things not lining up? Is the primary chain preventing things going in? Is the starting gear (#9 in the exploded view) hitting inside the case somewhere?

Make sure you have things installed correctly. Make sure that the starting gear has the bearings inside it and it's not "in front or behind" it.

Also make sure the starter clutch is seated on the starting gear completely. You need to spin the starter clutch as you slide it on. As you spin it...I think counter clockwise?...it'll slide right over the starting gear. There are three little rollers that prevent it from going on until they're spun and open up.

http://www.cmsnl.com/honda-cb550k-1978-usa_model7222/partslist/E++14.html#results

If you're still stuck post some pictures and we'll get this situated. It can be a little cumbersome holding all these parts and guiding things in.

Also, MAKE SURE that you don't loose any roller bearings that are in that little open cage in the starting gear. They will try to escape if given the chance. Use oil or assembly lube to hold them in place while putting them in. There is nothing that actually holds them in the cage until they're between the starting gear and shaft.

Hopefully this picture helps.




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1978 Honda CB550K

[markk]

thanks Dave,

I have both case halves together.  Should i have dropped these parts in first, before I put the case together?

There is just not enough space for the clutch and gear to go in together and get on the chain.

If I put in the clutch and then try to add the gear, there is just not enough space to get the gear inside the clutch.

Mark

[DaveBarbier]

Oh right, I forgot you have the case halves together. I've never put in the primary shaft assembly with the cases together but I'll reference the more knowledgeable Dave500 in his second reply that they can go back in but with just a bit of wrangling. It would have been easier to do it with the cases apart but shouldn't be a problem that you didn't.

Just so I can visualize this, you're doing everything through the oil pan, right? I see what you're saying about trying to put the clutch in first and there not being enough room to get the gear on. I'd try again first assembling the clutch and gear and trying to put it in the chain while rotating the crank a little. In my imagination, and honestly relatively little knowledge about these bikes compared to the old timers, that would be your best bet. I don't have any tricks up my sleeve for this, sorry. Just be sure the primary chain is fully seated on the crank sprocket teeth.

Maybe post a couple pictures just to make sure you have parts installed correctly?


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1978 Honda CB550K

[markk]

to dave500:

Are you saying I should be able to put the clutch and starter gear in through the oil pan when the case halves are together?

Do you have both piece together or clutch in first then add the gear?

Thanks,

Mark

[DaveBarbier]

You probably saw this post but if not, it might help to check it out.

http://forums.sohc4.net/index.php?topic=122084.0


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1978 Honda CB550K

[markk]

Thanks so much for that thread about the clutch gear.

I had it in 20 minutes after fighting it yesterday for an hour.

You guys are great and knowledgeable.

Mark

[DaveBarbier]

Great Mark, glad you got it.


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1978 Honda CB550K