I have a 1965 305 CA77 that is missing 2nd gear. The bike has 4500 miles on it and has been in storage for over 40 years. We got it running last year and the tranny was locked up. With a little help was able to get the bike to drive, however 2nd gear just chatters as I shift. Are there repair manuals available and how complicated is a transmission tear down and gear replacement?
Thanks for your help
2nd Gear Missing
Hi Tom, nobody else has had a crack at diagnosing your problem so I'll try to help. The way you are describing it, there was an issue before when it was locked up. Did you or your helper pull the gearbox apart to fix the lock up? If so, what was the condition inside?
The line about it missing second gear is interesting. Are the teeth stripped? That would possibly cause a lock up then slippage but it would be a real mess inside the box if that was so! Are you sure it is not the clutch chattering? That would be a far easier fix than stripping the gearbox. Providing that you are diagnosing the problem correctly and the chattering is from the gearbox, there is only one option and that is to strip the box. It's fairly straightforward, but all things are simple when you know how. The engine needs to be removed then turned upside down in order to split the lower case from the upper case. The left side cover needs to be removed. Then the clutch and drive sprocket comes off, (unless you are creative) and the cases can be split. Use new seals and gaskets when assembling. There is plenty of information in this forum and manuals available to assist you. I wonder if LM has heard of this problem before as I might be barking up the wrong tree? Regards Brian.
CA 77 2nd Gear MissingThank you for the reply, the information is very helpful and I will work on the gearbox when I have time. Sounds like a big project. I do not think it is the clutch, the other three gears work just fine. I think when the bike was young somebody had a lot of fun. The rest of the bike is in pretty good shape for its age.
Tom,
First, that's a nice looking Dream you have! Second, I agree with Honda Brian that it looks as if you need to get into the transmission, although it would be nice to have someone familiar with old Honda transmissions try to shift into second gear and diagnose the problem firsthand. When i had a similar problem on my CB77, it was caused by rounded edges on the gear dogs. These dogs are used to lock gears to each other, or to the shaft. Shifting is done by sliding the dogs to engage different gears. When they are rounded, they can make a "chatter" effect as they bounce back and forth into engagement. Mostly happens on second gear, maybe because of the big ratio jump from 1st to 2nd? As I say, it is good to have someone experienced in these things experience it first hand, as it's hard to diagnose over the net, and I'd hate for you to open up the crankcase if it's not needed. By the way, i've heard you can do this without pulling the engines, at least on CB77s. After pulling the battery and draining liquids, flip the bike so it rests upside down, and remove the lower cover. Voila. Let us know if you have the guts to try this! The picture below shows some of my gears. The teeth are great, but notice the slight rounding of the dogs on the center gear. Replacing that gear fixed my problem. Strangely, the dogs it meshed with were still OK. Larry-Pasadena
Larry has the correct diagnosis I think. I'm surprised that the teeth are worn after such low mileage though. Maybe the heat treating/hardening was not correct during manufacture. Don't forget when you you rebuild the tranny that there are offset cotters available to maximize dog engagement. Lifting the bike upside down is clever, but you will need a couple of strong mates!
Brian.
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