Topic: Has anyone replaced the seal in the cam chain tensioner housing on a CB750?

[markb]

I need to use the housing because it is sandcast (to be correct for engine E100) but the seal looks questionable to me.  It appears that the steel retainer would have to be pulled out to replace the seal.  Has anyone ever done this and know what seal is required?

[ekpent]

Need an extra to practice on ? Be a later 71-76 model   Eric

[Whaleman]

http://forums.sohc4.net/index.php?topic=52277.msg1532158#msg1532158

Here is a post I made years ago. I used a distributer rubber to seal the end from water. Maybe this could work if it was leaking a small amount. I don't think many leak. Dan

[markb]

Need an extra to practice on ? Be a later 71-76 model   Eric

Thanks for the offer.  I have several, later diecast ones I can experiment with.  If I can get the steel retainer out maybe it's as simple as swapping the retainer and seal with the one in the sandcast housing.  Might be hard to find a replacement seal.  Looks like I'll have to make a special tool to get it out.

Here is a post I made years ago. I used a distributer rubber to seal the end from water. Maybe this could work if it was leaking a small amount. I don't think many leak. Dan

Great idea.  Some good info in that link.  I had done a search but didn't find it.  Unfortunately it doesn't help for what I'm trying to do.

[Old Scrambler]

Mark.............try soaking the unit in wintergreen oil for a day or so.  I have also had good success with other rubber parts by soaking in Marvels Mystery Oil or JOY or DAWN dish-soap but it takes 10-days or more to get results. I had rock-hard intake rubbers return to 'like new' after a month of DAWN treatment.

[markb]

Hmmm, I might try that.  I'm guessing there isn't a lot of pressure against that seal.  I haven't tested it to see if it leaks but that would be easy enough.  I still think I'll take one apart.

[markb]

I had some time today so I made myself a little puller.


Here’s how it fits into the housing.  I had to put the fingers in first and then put in the screws to hold them.


Then I put it in the arbor press with a rod through the housing and the seal cup came right out.


There it is.  So it can be done.  It took me a couple of hours and I realize this is a big waste of time (because there are plenty of adjusters available on eBay for $5) unless you have a sandcast adjuster that needs to be saved.

[Whaleman]

markb, I'm confused. Why did you waste your time? Is the one you are working on sandcast? i did not even know these were sandcast on sandcast case engines. If it is can't you just buy an ebay one and change the seal to your special one? Dan

[markb]

This is the sandcast one and yes, they are different that the diecast ones you see on eBay.  If I could find a sandcast one I would buy it.  The seal was bad on the sandcast housing.  What I actually pulled out is the metal cup that holds the seal.  Then I pulled a good cup and seal out of a diecast one and put it in the sandcast one.

[markb]

I was looking on the Yamiya site and stumbled across this.  They make a puller for the metal cup and seal for the cam chain tensioner housing.  Unfortunately they can only sell it in Japan.  But it shows I wasn’t the first one to think about doing this.   

[Ellz10]

I was looking on the Yamiya site and stumbled across this.  They make a puller for the metal cup and seal for the cam chain tensioner housing.  Unfortunately they can only sell it in Japan.  But it shows I wasn’t the first one to think about doing this.   

I know uts been 7 years, but I just checked and purchased this tool. It's now available to us in the States. I'm getting my housing vaporblasted and need to pull the cup so this was relevant. Tha k you for your post, I wouldn't have been able to find it anywhere else; trust me I've been actively looking lol.