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Discussion Starter · #1 ·
Hi

I have a 1981 low milage CX500. I bought it after it being in storage for 20 years, and did the triple bypass and new clutch. I am now having issues that when under load it clunks and feels like a gear has slipped or is slipping. Its quite a loud clunk and immediate loss of power then almost bunny hops doing it. I thought there may be something wrong with the rear hub and drive but all the gears look good and feel tight. There is no metal in the oil and transmission looked fine when I had it apart. Any ideas would be much appreciated
 

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Discussion Starter · #3 ·
Does it do this in all gears or a particular gear{s}?
I only tried it in 1st today as I tried going up the hill out my drive. But I am pretty sure prior to stripping it did it in second when I tried as well.
 

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Discussion Starter · #4 ·
I only tried it in 1st today as I tried going up the hill out my drive. But I am pretty sure prior to stripping it did it in second when I tried as well.
Prior to pulling motor apart it only seemed to do it post the clutch being adjusted.
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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Prior to pulling motor apart it only seemed to do it post the clutch being adjusted.
That suggests your answer.
Is there adequate free play at the clutch lever?
 

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Discussion Starter · #6 ·
That suggests your answer.
Is there adequate free play at the clutch lever?
Prior to stripping the motor down, it started happening after too much free play adjustment. I wouldn't have thought you would get such bad slippage it sounds like tooth slippage?
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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You'd need to have a badly chewed transmission for gear slippage like that. I think it's either going to be the clutch or worn splines where the wheel connects to the final drive. It may be worth removing the rear wheel to have a look.
 

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Discussion Starter · #8 ·
You'd need to have a badly chewed transmission for gear slippage like that. I think it's either going to be the clutch or worn splines where the wheel connects to the final drive. It may be worth removing the rear wheel to have a look.
Thanks. I have removed the rear wheel and all gears look good and everything in the 90degree gearbox feels tight with a small amount of backlash. Will have a play with the clutch and see what I can find.
 

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Is it possible that the new clutch isn't properly engaged with the crankshaft gear?
 

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Discussion Starter · #10 ·
Is it possible that the new clutch isn't properly engaged with the crankshaft gear?
I will pull the clutch tonight and take a look, although with what I hear and feel as this is happening, I would imagine to see a few teeth in the oil if gears were slipping.

It does tend to lean towards clutch issues, although I have never experienced this sort of problem with a clutch where it feels like gear slippage due to the clunking
 

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Could it be engagement of the driveshaft with the output shaft?
 

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'84 CX650E that is evolving into a GL500
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If you didn't get the u-joint engaged with the engine's final shaft any chips would be inside the boot between the engine and the swingarm, not in the oil....
It is very easy to miss putting the bolt into the u-joint or not get it lined up with the groove in the final shaft.

BTW: Welcome to the forum. Please add your location and your bike's model and model year (NOT year first registered if that's what your paperwork shows) to your profile so that you don't have to remember to tell us every time and we don't have to keep asking when you forget (see Forum Settings link in my signature).

And welcome to the world of antique vehicle ownership (they own us, not the other way around). Your bike is about 4 decades old and the Previous Owners may or may not have done the maintenance necessary to keep it safe & reliable so it is highly recommended to download the Factory Shop Manual for your model (available through the CX Wiki - link in my signature) and go through all of the service procedures, regardless of whether your bike has reached the specified mileage.
I also recommend looking on all rubber parts with suspicion because rubber does not age gracefully. Check the date codes on your tires and replace them if they are over 5 years old no matter how good they look & feel (old rubber simply cannot flow around the irregularities in the asphalt well enough to grip, especially if it is cool or wet). If your bike still has the original rubber brake line(s) (should be replaced every 2 or 3 fluid changes = 5 or 6 years) I recommend shopping for modern stainless braided ones (they last practically forever and double the life of the fluid). And don't forget things like the rad hoses and the boot between the engine and swingarm (they can crack on the bottom where you don't see it).
 

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Discussion Starter · #14 ·
If you didn't get the u-joint engaged with the engine's final shaft any chips would be inside the boot between the engine and the swingarm, not in the oil....
It is very easy to miss putting the bolt into the u-joint or not get it lined up with the groove in the final shaft.

BTW: Welcome to the forum. Please add your location and your bike's model and model year (NOT year first registered if that's what your paperwork shows) to your profile so that you don't have to remember to tell us every time and we don't have to keep asking when you forget (see Forum Settings link in my signature).

And welcome to the world of antique vehicle ownership (they own us, not the other way around). Your bike is about 4 decades old and the Previous Owners may or may not have done the maintenance necessary to keep it safe & reliable so it is highly recommended to download the Factory Shop Manual for your model (available through the CX Wiki - link in my signature) and go through all of the service procedures, regardless of whether your bike has reached the specified mileage.
I also recommend looking on all rubber parts with suspicion because rubber does not age gracefully. Check the date codes on your tires and replace them if they are over 5 years old no matter how good they look & feel (old rubber simply cannot flow around the irregularities in the asphalt well enough to grip, especially if it is cool or wet). If your bike still has the original rubber brake line(s) (should be replaced every 2 or 3 fluid changes = 5 or 6 years) I recommend shopping for modern stainless braided ones (they last practically forever and double the life of the fluid). And don't forget things like the rad hoses and the boot between the engine and swingarm (they can crack on the bottom where you don't see it).
Thanks for that, will update details later on once I am back home.

The u-joint was definitely engaged and I have the whole drive from the engine back stripped down and cleaned and it all looks and feels really good. no metal in that boot at all.

if it is not the clutch (which I still have my doubts) then I am stumped, but ultimately may have to pull the motor again.
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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When I put my GL650 back into service this summer, I was getting very clunky shifting and under acceleration, it sometimes seemed to slip out of 4th or 5th gear, then back in. I replaced the clutch basket, and it's much better. Both baskets rattle as if the damper springs are loose, so I'm not sure what is different to make the newer one better.
 

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...I have the whole drive from the engine back stripped down and cleaned and it all looks and feels really good. no metal in that boot at all.
Are you saying that the bike is disassembled at this time? You have taken this all apart since this problem developed?
 

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Discussion Starter · #17 ·
Are you saying that the bike is disassembled at this time? You have taken this all apart since this problem developed?
I have stripped down from the engine back (not the engine), so the drive shaft and 90degree gearbox etc. Yes.

I have also pulled the clutch out to inspect. Motor is still in though. Thats only probably an hrs work to do what I have done...
 
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