[ts354]

Got the old 1970 CB450 running. I stuck the shifter lever on the shaft coming out of the engine case. Ran through the gears fine. Went to down shift and wouldn't go. I applied a little pressure and it felt like it was grinding a gear. Not good. Then I noticed how much play there was in the shaft and found the old worn out rusted snap ring was just riding up on the shaft. See Pic.

How bad is it. Do I have to split the case to get it to line back up?

 

[66Sprint]

Possibly, but probably Not,...You'll want a new snap-ring... (make sure you install it with "sharp" edge side out, rounded corner side in).....
Likely worst case, you may need to remove the right side case cover and check the shifter mechanism for bends or other damage, and R&R as needed....Best case, install new snap ring and go....

Feel free to phone while at bike......540-525-5199

 

[Alan F.]

This diagram may be of use:

https://www.partzilla.com/catalog/honda/motorcycle/models-with-no-year/cb450k5-a/gearshift-spindle-kick-starter-spindle



Here's the circlip: https://www.partzilla.com/product/honda/94510-12000?ref=c36ef6138c42d164f1403b300f6c448ca7519554

 

[ts354]

So I probably just got the right side out of whack/sync. Phew, there for a minute I thought oh darn there goes the shift drum sync!!! And what I felt like a gear grinding was probably just the right side linkage stuff hitting the clutch basket.

 

[12ozPBR]

Follow the advice and resources given above and it’s worth mentioning that the washer behind the circlip is a “special washer” with a unique shape and it’s no longer available from Honda so make sure to save yours and reuse it in the same orientation.

 

[66Sprint]

On general principle, I would remove the right outer case cover and inspect for pawl positioning, related damage, metal swarf, etc.....

 

[David Babbitt]

I've had one of the fork shifters break one of its arms in the past, or found it broken on disassembly as the engine was given to me. I used a wire feed arc welder to reattach, with careful alignment, and still have it running fine.

And while you're at it, check the 1" or so diameter washer that rides on the end of a drum, keeping it in the gear it is at. See if it has an out-of-round inner hole. If so, you can make a new axle for that washer by using a nail cut off with its head, a 1/4" copper inner washer from copper tubing that the larger washer can use as a new bearing surface. Peen over the nail to keep the modified assembly together. Have more detail if interested.

 

[ts354]

Got it. Thanks everyone. Took the right side cover off and the spring (#3) in the above diagram was sitting on a little ledge by the kick start shaft. It had come off and the pawl was not engaging with the drum sprocket. If that makes any sense
Got lucky on that!!!! It very easily could have gone somewhere and got chewed up or fell in the drain pan full of oil like the right cover did. Along with all the cover screws. Ugg, oil everwhere....