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Discussion Starter #1
I'm replacing the ball steering bearings with roller bearings. My issue wih this is that the stem does not protrude through the upper bearing enough for the nut to thread on (threads are not visible). I discovered this when trying out the length prior to mounting the lower race that goes on the stem on the lower tree. The upper race in the neck is pressed all the way down in its seat, so that's not the reason. The bike is a -82 CM400T and I'm pretty sure the tree is the original one. It did fit just fine with the ball bearings.

Any advise from any of you guy's?
 

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This sounds like something I experienced with my rebuild, except I had a CB360 frame and CB450 forks and stem. I ran into the same issue and had to do a hybrid bearing replacement of tapered bearing at the bottom and new ball bearing race system (from CMSNL) up top, just so that I can get some threads. The ball bearing race system up top was a few mm thinner than the tapered bearing system. Since you have all original parts, its strange that you have this issue. For a sanity check, did you double check that you have the correct kit for your bike? Did you use a punch to ensure that your races are recessed all the way in?
 

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^^^and what brand is the tapered bearing kit? Most of us have used the AllBalls kits and they work great in virtually every case, but we've seen others not so much
 

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Discussion Starter #4
I'm using a kit from Pyramid Parts, they only use bearings from "known" manufacturers. The kit I use has the industry standard code SSH750 and here's a link to it: https://pyramid-parts.com/products/steering-head-bearings-kit-22-1011-SSH750-BR29

I might end up going the same route you have, with a ball bearing up top.

It could also be that my stem is not the original. Is there any way of figuring out the original's length from the seat surface for the lower race on the stem to the begining of the lower thread (that should hold the nut that secures the upper inner race on the stem?
 

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Is there a washer on the bottom of the stem, below the bearing?
Are you sure the lower race is seated all the way into the neck?
 

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Discussion Starter #6
Is there a washer on the bottom of the stem, below the bearing?
Are you sure the lower race is seated all the way into the neck?
The stem is to short even without a washer and the races are well seated.


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The stem is to short even without a washer and the races are well seated.


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I had to ask, because the lower race actually gets pushed up into the neck a ways - it does not sit flush with the bottom of the neck.
 

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They're a US company so since Honda stopped the 400 engine in 1981 for the US there wouldn't be. Use the '81 kit and you'll be fine.
 

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Discussion Starter #11
They're a US company so since Honda stopped the 400 engine in 1981 for the US there wouldn't be. Use the '81 kit and you'll be fine.
I guess the top bearing would be enough as that’s where the problem lies. Shipping is almost twice the price of the bearing though...sucks
Waiting for a bearing from Germany that might do it. If not, I’ll order one from All Balls.


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Good to hear! Let us know if this corrects your issue.
 

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Discussion Starter #17
Good to hear! Let us know if this corrects your issue.
When I got the washer that goes under the lower race on the stem I concluded it was a couple of 1/10 mm thin and that the diameter was way to large to fit in the head. Instead of making a fuzz with the supplier I used my lathe to machine a new one. I also noted that the sealing, that goes under the said washer is to large to enter inside the head, having it rest on the ”end” of the head adds required washer thickness. So the next step will be to replace it with a sealing in smaller diameter.
BTW when trying to screw on the nut on the stem I lost grip of it and it got stuck between the tank and the frame. So I guess the tank is going of ... Might ad well paint the bugger while I’m at it... Ever heard of projects that just keep growing?

Washer without sealing under it:
 

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Every project I've done has grown... it's that thing about doing one part and then noticing another part doesn't look that good any longer next to the part you've done. It all works out for the best in the end!
 

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It's always a good idea to measure the height of the top and bottom race assemblies and compare them to the new parts before you start driving parts into place.
 

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Discussion Starter #20
I have now come to the stage where the lengths of the parts add up. So far so good...
However, when looking through the workshop manual it appears there should be a lock washer under the nut that tightens the stem to the bearings. There was none on my bike! Does anybody know where I can find one?
 
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