Shift Cam and Case Damage

[wherearewe]

Hi Guys

Working away on an old basket case motor rebuild. Removed the shift fork assembly and i found some interesting / concerning wear.

There is this obvious crack in the case. It's not gone right through, but it has distorted the case where it protrudes near the front sprocket and is very close to the needle bearing for the shift drum.
Secondly, when i removed the shift drum i found this wear pattern at the other end. Ive already ordered a complete and good used fork assembly plus a NOS needle bearing (and my shift forks were pretty wasted). Im investigating case repairs.

My question is: wear like this on the shift drum, what would cause it? Could the case be bent slightly causing the drum to move out of alignment from the crack? Or is it just high miles? It doesn't look normal too me

 

[gggGary]

Idiot PO ran worn out chain until it skipped teeth on the sprocket, if you look at the bottom of that crankcase stand off you will see the two marks where the chain hit it. You usually see a bent clutch push rod also. For my money this is game over for the cases.

 

[TwoManyXS1Bs]

With that score line going almost completely around the shiftdrum, except near the 5th shiftpin, tells me that it's aligned with the shift stopper wheel, and its pin. Probably from a previous unrelated history. You can confirm this by fully rotating the drum 1st to 5th and back to 1st, and see where the score line endpoints begin and end. My best guess is they will start/stop where the stopper wheel axle pin is located. Could check for marks on the stopper arm. I can't think of any future problems that would be caused by that score line. But, a rotary/cycle test, to see if the score line introduces problems would be prudent...

 

[wherearewe]

Idiot PO ran worn out chain until it skipped teeth on the sprocket, if you look at the bottom of that crankcase stand off you will see the two marks where the chain hit it. You usually see a bent clutch push rod also. For my money this is game over for the cases.

Yeah i saw the chain marks... You dont think that crack can be effectively repaired? For me finding a set of cases isn't so simple. I'd prob have to ship them internationally.

 

[wherearewe]

With that score line going almost completely around the shiftdrum, except near the 5th shiftpin, tells me that it's aligned with the shift stopper wheel, and its pin. Probably from a previous unrelated history. You can confirm this by fully rotating the drum 1st to 5th and back to 1st, and see where the score line endpoints begin and end. My best guess is they will start/stop where the stopper wheel axle pin is located. Could check for marks on the stopper arm. I can't think of any future problems that would be caused by that score line. But, a rotary/cycle test, to see if the score line introduces problems would be prudent...

Ill have a look, but regardless I'm retiring this shift drum. This droids seen a lot of action...

 

[gggGary]

Sorry about that, I'm guilty of living in the US of A, cases are a dime a dozen here. I don't think that area is super stressed if the chain doesn't skip.

 

[TwoManyXS1Bs]

I don't think we have a good case weld/repair thread on here.
Excellent opportunity to gain fame and notoriety...

 

[wherearewe]

Ok so i investigated further. Cleaned up the case further and sadly the more i looked at it, the more i felt replacement was a better option. The crack around the bearing just didn't look good.

I spoke to a couple of engine restoration / machine welding specialists. Both told me that the distortion from the welding could cause problems. Since i can get new cases (albeit not easily) thats a safer option.

So sadly, no case repair thread here today. On the plus side, any one got a set of cases? It's not practical for me to get a complete engine because of shipping weight. Anything i find here in NZ will likely be shagged too, much like the motor i've been working on.

Are the 447 top end's/cases interchangeable through out years? This motor was an 81.

 

[SlowMaintenance]

It was my understanding that the cases are matched by number on the top and bottom halves and machined to fit only their counterparts. There was another member on here who was merging two cases together, saw his post last week but can't remember who it was. Hopefully he'll be by shortly to comment with his experiences.

Best of luck!

 

[XSLeo]

The upper and lower case halves are number marked. Best to keep matching numbers. The case are cast then the parts are bolted together for line boring of bearing races.
So mismatched case halves may not have lined up holes.
The same with heads and rocker boxes.
At best they might work, possible oil leaks or enough misalignment to cause bearing issues.
Leo

 

[wherearewe]

I decided to buy a new set of cases. Wasn't going to mess around trying to pair an upper from one year with a lower from another. Got a pretty nice condition set from an 80SH. Will continue to build from them. They didn't cost much themselves, but the shipping was heavy... You yanks should count yourselves lucky...

 

[wherearewe]

So new cases arrived today in NZ. Guess what. Looks like they were dropped along the way. Front right lower half cracked and dented along the gasket mating surface. The photos don't show it well but its pretty badly deformed. Not sure if they are repairable, but the gasket won't seal anymore i can see that. Would have to built up with a weld and then be milled flat or something. Not an easy task nor cheap if at all doable.

Ive contacted the ebay seller (a wreckers in the states) regarding insurance. Lets see how this pans out before i name and shame. He has a lot of xs650 stuff online so chances are heaps of us have looked at his stuff. There's no insurance listed on the packing slip for USPS though so its not looking promising...

Honestly, i can't get a break!

 

[TwoManyXS1Bs]

Well, .........CRAP!!!

Now you've got a good upper and your old/good lower.
That shouldn't be used together.

And, your old/bad upper with a damaged lower.
That shouldn't be used together.
Unless for mockups.

Hoping this gets resolved...

 

[gggGary]

throw em together, see how the holes look?

 

[wherearewe]

throw em together, see how the holes look?

What do you mean Gary? Try and fit one half from each set? I thought that was a big no no.

Or do you mean fit a cover and look at the damage / warping? If thats what you mean, well i can see daylight coming through the dent so she's gonna be a leaker!

Honestly if they had just been packed a little better

 

[Signal]

That sort of thing really hurts.
I have some ideas :
1.Use Yamabond on the gasket.
2. Build up the bruised area with metal set or similar and sand it flat using wet and dry on a large flat surface.
Try an experimenting with the cases empty, assemble them and put some oil inside to see if it stays there. Less of a pain if it still leaks.

 

[member3480]

Years ago I had no choice but to fix cases and it was a 50/50 shot that it worked. Guys use to put small sprockets on front and chain would come off and go right threw cases. There use to be a company that sold these rods that I used to fix the cases. Don't know if you can still get them. Any large amount of heat will distort the cases so you have to be careful. Next time you need cases contact me and I will send you a good set out (Matched upper and lower) . I have also used different tops and bottoms and if close to same year they worked fine. It has to do with casting runs over the years that may leak. I use to be a Honda dealer and I was able to get a top or bottom from the factory with the matching number but were never mated until I did it. So if your bike is a 77 I would go up or down a year if you had to do it that way. Again if you need a good set I got two sitting under my bench.

 

[TwoManyXS1Bs]

There use to be a company that sold these rods that I used to fix the cases. Don't know if you can still get them...

The new company that sells those is Muggyweld.

http://muggyweld.com/aluminum-repair

 

[wherearewe]

Ive actually got some of those rods (or something very similar). They are pretty cool. Ive used them to successfully repair chips in non critical areas on thin stuff. Works pretty well and they were my first thought, but I'm not sure how it would hold up long term under pressure and heat cycles, or how well i could get it all perfectly flat afterwards. Id need a machine shop to mill it back down. Also i'd need a Oxy gas torch to produce enough heat in the cases to get good fusion which i dont have.
Anways I'm asking around again about repair. I think this damage stands a much better chance of being fixable. Its not really close to any bearing surfaces, the crack is shallow, and the surface could be built up with minimal heat. It's not what i wanted though.

 

[wherearewe]

Years ago I had no choice but to fix cases and it was a 50/50 shot that it worked. Guys use to put small sprockets on front and chain would come off and go right threw cases. There use to be a company that sold these rods that I used to fix the cases. Don't know if you can still get them. Any large amount of heat will distort the cases so you have to be careful. Next time you need cases contact me and I will send you a good set out (Matched upper and lower) . I have also used different tops and bottoms and if close to same year they worked fine. It has to do with casting runs over the years that may leak. I use to be a Honda dealer and I was able to get a top or bottom from the factory with the matching number but were never mated until I did it. So if your bike is a 77 I would go up or down a year if you had to do it that way. Again if you need a good set I got two sitting under my bench.

Next time i need cases? Ha i might need some now! You know how much shipping cost though. We looked at it. It was heavy. This guy had a pretty good freight price, i assume he sends a lot. If we could find a way to match it or be close... Ps. The cover is on the way from Portland. Should arrive today or tomorrow. Shame i dont have a motor to match...