Suggestions to fix a broken 5th gear

[Kabonkie]

I finally got my 83 550 L down and pulled the engine out. It's original issue was that it was stuck in two gears or at least the output shaft is stuck solid. Engine would run with the clutch pulled in, but I could not get it in another gear.

So as I said I have the engine out, and pulled the oil pan off the bottom. And there floating around was pieces of a gear. From what I can look in the bottom and see, it looks like 5th completely shattered. The biggest piece is about a fourth of the gear and a whole bunch of smaller pieces. I'm still working on removing all the bolts and screws to split the cases. I did print out a suggestion from Kaptain Ketchup of using long bolts.

I have a complete transmission from a 85 550 L so not worried about replacing the gear. My question has to do with why did it break? The bike had oil in it with only about 650 miles on it. It did run 450 miles the day before, but I would have expected most of that in 6th gear as these were highway miles. I know that this would all have to be hypothetical as, I don't even know the whole history of this bike and what kind of treatment and maintaince it has had. But any suggestions would be appreciated. And any suggestions on how much of this to replace would also be appreciated. Like I said I have a whole transmission, so would it be better to replace the whole thing, or would just the gear alone be okay?

Roger

[duaneage]

Hey $hit happens, maybe just bad luck.

Working on these things requires a host of tools and patience, not necessarily in that order. Read the Clymers manual chapter on rebuilding the box since that is what you will effectively be doing and see if your still interested.

It might be easier to replace the engine adn transmission alltogether, I think a 650 driveline might fir that frame :twisted:

[Kabonkie]

I didn't need the longer bolts after all. After removing all the bolts and screws, a couple of taps with a dead-blow hammer and she seperated without problems. Maybe I was just lucky with the split.

As I said before I have the complete guts to a 85 550 L already. Gears look great, shift forks look brand new. So its a repair, not a replacement engine. From what I've seen, an engine, in who knows what condition, starts at $200 here, and that would probably be one without cylinders.
I bought the complete transmission, all the gear sets, shift forks and all the rods for $20 and it was shipped to me for $8. Gaskets to put it back together will cost no more than $50. So for under $100 I still have my good running 550 and a transmission in known condition. So I still have under $800 tied up in the complete bike.

As for what happened, I now know and have a good idea of the sequence of events. Looks like one of the PO's that had it before was hard on it and hard on the shifting. The shift fork that rides on the dog area of 6th, looked like it broke off a piece. This created a sharp edge on one side. This ground into the area that it rides on and eventually the dogs cracked and fell off of 6th gear. Sometime after that, those pieces got into 2nd gear and caused it to shatter. All that was left of 2nd was pieces, and not one left on the shaft. Other than two bad gears, nothing else looks bad.

I decided to replace all the shift forks, and the complete gear sets. Two reasons for this, one is because I don't have to try to remember which gear went where and the second because when you usually change out a gear set on a car, you always change out the pinion gear when you change the ring gear and vice versa. I figured this newer set has ran together as a set, so if I introduced one or two gears from another that have worn marks from the other gears, I might get a whine or growl until the gears wore together. Changing out the whole set puts the same gears together that have already worn together. Now I may still get noise, but it should be less likely to happen. And replacing worn and broken shift forks with a set that looks brand new is a no-brainer.

Now while the engine swap would have been the faster way of doing this, money is an issue. I also end up with a known engine, and now a known transmission. And I do it for a whole lot less money. And as far as the work, it's just that. Any one that knows me, knows that I don't mind getting my hands dirty and doing my own work, in fact I hate to say this, but I'm only one of two people that I trust to work on my stuff.

If the gaskets arrive this week, and I can convice my son to help a little, I should have this back into the bike, tuned and running by the 27th or in about a week.

[Tv]

Thanks for the post Kab. I need some inspiration to get set to do the tranny in my GSX1100. Still don't know whether I will try it but I'm interested to see how you go.
REgards
Tv

[mark]

This is interesting to me to. I have an old 850 engine that I'd like to take apart and at least look at (someday?). Pics of how you pull it and replace it would be interesting.

[Don Lobacz]

Absolutely replace the whole set, many things could be wrong with the old gears. Also, check the shift drum for dimples in the grooves. A little freeplay on the drum can let gears jump out of gear.

[Kabonkie]

Mark, I didn't take any during the pull process. But I'll take pics of when I put it back in. Wasn't too hard as it came out the right side.

Don, that was my thought exactly. In fact was going to replace it all at the same time, the shift forks and drum.

I've got the newer gear set in, and does it ever run smoothly. Probably tomorrow afternoon, I'll pull the drum and shift forks and replace them as well.

Here is are the pics. Look at the first shift fork on the right hand side.


A picture of the engine before I split the cases sitting on the bench.


A nekkid bike!!


6th gear notice where the dogs should be..


And this is what is left of second.

[Anonymous]

8O Wow! Thanks for the pics. Hope I never have to see this part (parts :roll: ) of mine!

[SqDancerLynn1]

I'm not sure on the 6 speed?? Doesn't 2th & 5th work together ???
Could have been a bad shift to 2th

[Kabonkie]

SDLynn, it was 6th, not 5th. I've checked that gear over and over. These two gears are on opposite sides of the shafts from each other, and don't mesh together.

So had to be the dogs off 6th that got into second.