80 gs 550e. probably a bad transmission. help me diagnose/replace it!

[egetron]

How did you do that without removing the gears from the shafts?

I just checked the gears the best I could while they're on the shaft. It looks like it's not been used much all around, so I'm making an assumption that the parts I can't see without taking it off the shaft are ok too. I'm avoiding taking it off the shaft, because I've read it takes special press tools and expertise to get it back together.

I'm keeping my options open, I've been trying to source a new engine as well. I may attempt the transmission/engine rebuild anyway just to see if I can do it, but in the meantime, It'd be nice to have a replacement engine so I can ride the thing.

How much should I expect to pay for an engine in reasonable condition?

I found this within driving distance of me (trying to avoid shipping costs). 400 bucks seems like a bit much, especially since he doesn't know the history of the engine:

http://www.ebay.com/itm/380160627705?item=380160627705&viewitem=&sspagename=ADME:X:RTQ:MOTORS:1123&vxp=mtr

Where can I find a decent replacement engine in southern california?

-Ege

[Maddevill]

thanks for the reply Maddevill, I'll go ahead and check that tonight.

If it was the sprocket, wouldn't that make itself apparent in every gear though?

also, probably a dumb/searchable question, but how do I check the sprocket? Do you mean the one on the rear wheel or the one in the engine? Or both?

Well, possibly. Check by looking at both sprockets for worn/ broken teeth. See how much the chain can be lifted off the sprocket teeth. if it's more than half a tooth your chain/ sprockets are worn. It still may be your tranny but it's always better to eliminate the simple to fix stuff before tearing into the motor.

[eil]

$400 does sound a little high. Try posting in the Parts Wanted section. Typically if someone here has one to offer, you'll get a better price than FleaBay. And you're more likely to get an honest answer as to the true condition of the engine as well.

Keep your eye open for a parts bike as well. It's sometimes the case that you can part out the rest of the bike and effectively get the engine for free. (Although if it's a parts bike, you do run the risk of that transmission and/or engine being bad too.)

[egetron]

ok, assuming I talk this guy down to a lower price... and I drive out to check out the engine...

What tools/procedures should I have/know when I'm checking out the engine before I buy it? Is there a way for me to test compression when its sitting by itself? Is there a way for me to test the gears?

I understand there's a lot of risk in buying an engine with an unknown history, but I want to check for as many things as I possibly can before I purchase it.

Thanks for all your help everyone.

[almarconi]

Have you considered taking your bike to a local repair shop and having them diagnose the problem? It may be worth paying a mechanic an hour of their time so they can go over the bike and figure out what is wrong. Once you know for sure what the problem is then you can decide how you want to repair it.

[egetron]

Hello guys, It's been a while, but since my last post. I've actually decided to ignore all of your sound advice and dive into the case myself.



So as I mentioned earlier, I was expecting to find missing teeth, clearly bent shift forks, or some other clear sign of trouble, but upon initial inspection, everything looked like it was fine. This was disheartening, because I didn't want to have torn apart my case when the actual problem was something simpler.

Anyway, upon more careful inspection, comparing the transmission I received from ebay and the one in my bike, I realized that the engagement dogs on my transmission were actually pretty rounded off. Are the ones that I highlighted for the second gear? Have I found my problem? It's hard to tell from the picture, but the dogs (are these the dogs?) that I've circled in the picture on the left are actually pretty worn on the corners, at least compared to the "new" transmission I have.



It seems like I might as well replace the old transmission with the "new" one.

The only problem with the new one is that when I spin the bearing on the shaft, it seems to not be so smooth. Will this take care of itself once they are oiled? Or do I need to replace the bearings on the "new" tranny.

[almarconi]

What you need to inspect are the slots on the inner side of the gears and the dogs that engage the slots.

Here is a picture of a worn gear slots
[/IMG]

Here are some worn dogs


The bearings typically get little wear since they are covered in oil. If yours are notchy then they should be replaced. Also carefully inspect your shift forks and shift drum for wear.

[egetron]

Does anyone have any pictures of non-worn transmission dogs and slots? Do they come
From the factory with a slight bevel or are they sharp edged? Trying to gauge the status of this eBay transmission.

[almarconi]

Why not post some pictures of your gears? The edges are not really sharp but machined and square, not rounded and worn looking.

[egetron]

came out of my bike; have I found my problem?:



here are the replacements I have; you think swapping in these will fix my problem?





thanks all.

[almarconi]

Why are you being lazy? All you need is snap ring pliers to remove those gears. Once you have them removed you can inspect all the gears including the ones on your ebay transmission.

To answer your question, your gear looks pretty worn out. I'm sure if you inspect the dogs of the mating gear it will also be worn. The replacement looks a little better but still has wear on it. If you don't plan on keeping the bike just install the used parts and hope for the best. If you plan on keeping it, replace the worn out parts with new parts.