GS450 Catastrophic failure

[93Bandit]

Thanks for the advice GregT, but the engine's been buttoned up already..

Gentle riding, oil change after 100 miles, and everything seems ok so far. I reverted the final-drive gearing back to stock, the limited top speed is annoying but it'll have to do till I get the GS1000 online.

Happy 4th everyone!

What a happy ending. Congrats on getting it back together. Happy 4th to you as well.

[Rijko]

Just a thought, that trans probably was overloaded bad.

The combination of gearing and sticking rear brake may have been too much ... very heavy on the drive train.
I would fix the brake, if it does not simply stick a bit but locks up you may end up on your ass after all ..

[Rijko]

... I'd been having an issue with a sticky rear brake, but a roll back by about an inch or two would always unstick it..

Bad habit, the bike let you know it has brake issues.
Hope what you take away from this is don't postpone maintenance, especially with your brakes.
You have been putting your life on the line.

Not trying to be rude, but this is .. well, you know the word i am looking for.
Let's go with 'careless'

[free99]

Bad habit, the bike let you know it has brake issues.
Hope what you take away from this is don't postpone maintenance, especially with your brakes.
You have been putting your life on the line.

Not trying to be rude, but this is .. well, you know the word i am looking for.
Let's go with 'careless'

Well unfortunately I'd tried fixing that issue a few different ways before discovering the spindle for the brake lever itself needed a thin oil to help make it de-assert on the rear brakes.

[free99]

Bike's been stock gearing these past few weeks. No brake issues, replaced front bearings but that's been it... until yesterday, when the transmission s#it the bed again.

Accelerated away from a light, shift up to second with the clutch pulled all the way in and... CRONCH.

Walk of shame on the sidewalk back to my house with my bike. I'm moving on to working on my GS1000, I'm just too frustrated to focus on the 450 right now. Back to bicycle riding around town like my college years as I don't have a car. At least I can get rid of the little bit of weight I've gained these past few months.

[Rob S.]

Second transmission, and second transmission failure? It'll be interesting to find the culprit, though you may want to leave that to the next owner. Please keep us advised.

[free99]

Haven't taken a look at the system physically. But I pondered through any recent changes I've made, and realized both transmission failures occurred after changing the clutch ramp.

A bit more than a month back, my chain skipped a tooth and shredded the little actuator shaft as well as the clutch actuator ramp; I recall reading somewhere on here that the GS500 had a nicer clutch ramp on account of not being made of a greased piece of plastic but instead a nice set of ball bearings on a metal ramp.

The GS500 ramp fit right into where the 450 assembly went, and after removing 95% of the play on the clutch rod adjustment, loved how much easier the clutch could be actuated.

Now I'm wondering... both failures seemed to happen while shifting from first to second. Broken circlip found the first time, haven't taken a look for the second. I wonder if the clutch didn't get fully disengaged and this caused tooth damage somehow? But that doesn't make sense, wouldn't it only chip the leading edge of one of the transmission dogs?

How could I examine the transmission while the engine is all together?

GS450 Ramp: s-l1600.jpg


Replacement GS500 ramp:


Ramp 500-1
Ramp 500-2

[GregT]

Engine out, upside down, drop the sump, you'll see most of the transmission. Again, check the endfloat on the shift drum.

[free99]

Notches are probably identifiers for semi-skilled labour on the assembly line.
Before assembling the box, check the endfloat on the shift drum. If that is excessive it can put load on the circlips between gears. Should be only just discernable movement - about 003- .005 in.

I really wish I'd managed to read this before I had closed up the engine. Will do Greg, thanks.

Just to be sure (because it looks like no based on memory), there's no way to check that without at least taking off the clutch side of the engine housing right?

[GregT]

With the sump off from memory you can see the shift drum. Levering it side to side will give you an idea of how much endfloat it has.