R80/7 clutch problem

Rockman · 10-28-2012, 06:52 PM

I am in the process of reassembling a R80/7 I got as a semi basket case. I put the flywheel, clutch and gearbox back on. All seemed well. Bike starts and runs well and at first the clutch seemed fine. Suddenly though, the cluch freeplay increased a lot, and the bike now issues a graunching noise when I pull the clutch lever and pulling it right in can stall the motor. I cant see how I could have mis-assembled it but maybe I did.

If I dont touch the clutch lever all is well. It starts and runs as it should and the gearbox changes through all gears without problems.

Obviously the gearbox and probably clutch has to come out, but has anyone got any suggestions as to what is going on?

pommie john · 10-28-2012, 07:08 PM

I'd have a look at the thrust bearing ( throwout bearing) before I pulled the 'box off.

Rockman · 10-28-2012, 07:13 PM

Quote:

Originally Posted by pommie john

I'd have a look at the thrust bearing ( throwout bearing) before I pulled the 'box off.

Did that, its ok. Pulled the push rod out, its ok. Dunno what the problem is.

disston · 10-28-2012, 07:16 PM

This doesn't make sense. You kill the motor by pulling in the clutch lever, but you can shift the bike with out using the clutch lever? Actually it is possible to shift the bike w/o the clutch except for getting it out of neutral.

It does sound like you had the gear box with all the throw out pieces in the trans and maybe you put this in the bike with out removing them for cleaning and greasing. You can do that now with out removing the box. Leave the long rod, #1, in place but take out the thrust pieces and bearing. It's possible you need a new bearing. If this stuff is dry and/or corroded it can destroy the transmission rear cover.

Rockman · 10-28-2012, 07:23 PM

Quote:

Originally Posted by disston

This doesn't make sense. You kill the motor by pulling in the clutch lever, but you can shift the bike with out using the clutch lever? Actually it is possible to shift the bike w/o the clutch except for getting it out of neutral.

It does sound like you had the gear box with all the throw out pieces in the trans and maybe you put this in the bike with out removing them for cleaning and greasing. You can do that now with out removing the box. Leave the long rod, #1, in place but take out the thrust pieces and bearing. It's possible you need a new bearing. If this stuff is dry and/or corroded it can destroy the transmission rear cover.

Yes thats my problem, it doesnt make sense. And yes I have all the bits in the diagram above and they are all in good condition as far as I can see. The drive shaft is still diconnected, so its not a big problem to pull the box off and have a look so I'll do that I think.

Rob Farmer · 10-29-2012, 04:47 AM

I'm not saying this is the issue but I had similar symptoms when the spot welds came away on my clutch. I only found the problem when I removed the whole clutch. If you're completely out of ideas when you've checked everything else it may be worth a look.

FR700 · 10-29-2012, 05:18 AM

Quote:

Originally Posted by Rockman

I am in the process of reassembling a R80/7 I got as a semi basket case. I put the flywheel, clutch and gearbox back on. All seemed well. Bike starts and runs well and at first the clutch seemed fine. Suddenly though, the cluch freeplay increased a lot, and the bike now issues a graunching noise when I pull the clutch lever and pulling it right in can stall the motor. I cant see how I could have mis-assembled it but maybe I did.

If I dont touch the clutch lever all is well. It starts and runs as it should and the gearbox changes through all gears without problems.

Obviously the gearbox and probably clutch has to come out, but has anyone got any suggestions as to what is going on?

Was the crank chocked ? ... thrust washer fall off the back off the crank ?

Increased free play may suggest that the crank is moving forward taking the clutch and flywheel with it. Is the flywheel hitting the back of the engine block ?

.

Rockman · 10-29-2012, 03:02 PM

Quote:

Originally Posted by FR700

Was the crank chocked ? ... thrust washer fall off the back off the crank ?

Increased free play may suggest that the crank is moving forward taking the clutch and flywheel with it. Is the flywheel hitting the back of the engine block ?

.

You've hit the nail onthe head there. I was looking through the box of bits that came with it last night and found the thrust washer

. Took the gear box and clutch off. I'll order a new rear main seal before I go any further as I'll probably destroy the old one getting it out. At least I know what the problem is now.

Airhead Wrangler · 10-29-2012, 03:11 PM

d

Quote:

Originally Posted by Rockman

You've hit the nail onthe head there. I was looking through the box of bits that came with it last night and found the thrust washer

. Took the gear box and clutch off. I'll order a new rear main seal before I go any further as I'll probably destroy the old one getting it out. At least I know what the problem is now.

You guys are talking about two different things. Sounds like you left out the clutch spacer (not a thrust washer). If the thrust washer had fallen out of it's locating holes on the back of the block and you torqued down the flywheel, the engine wouldn't even turn, it would be locked, so it's not that. What you found in the box is #5 below, right? It belongs between your flywheel and #12

Rockman · 10-30-2012, 03:50 PM

Quote:

Originally Posted by Airhead Wrangler

d

You guys are talking about two different things. Sounds like you left out the clutch spacer (not a thrust washer). If the thrust washer had fallen out of it's locating holes on the back of the block and you torqued down the flywheel, the engine wouldn't even turn, it would be locked, so it's not that. What you found in the box is #5 below, right? It belongs between your flywheel and #12

The parts I have loose in my box of bits are 1 and 3 places forward of the seal - round plate with holes in it and round plate with copper? segments. I might also have #5, not sure..

I havent had time to pull the flywheel off yet but will on the weekend. Obviously something is missing, just not sure what.

FR700 · 10-30-2012, 04:51 PM

Quote:

Originally Posted by Rockman

The parts I have loose in my box of bits are 1 and 3 places forward of the seal - round plate with holes in it and round plate with copper? segments. I might also have #5, not sure..

I havent had time to pull the flywheel off yet but will on the weekend. Obviously something is missing, just not sure what.

How much end float does the crank have now ?

from maxbm' -
http://www.maxbmwmotorcycles.com/fic...2&rnd=08102012

Airhead Wrangler · 10-30-2012, 05:56 PM

Sounds like FR700's right then. Yikes. It might be time for a larger tear down. Pull that flywheel and see what's there... or more importantly what's not, I guess.

Rockman · 10-30-2012, 08:49 PM

Quote:

Originally Posted by Airhead Wrangler

Sounds like FR700's right then. Yikes. It might be time for a larger tear down. Pull that flywheel and see what's there... or more importantly what's not, I guess.

Yup - weekend coming up. Funny thing is that it runs well - no odd noises. I'm still hoping for something simple.

Rockman · 11-04-2012, 03:22 PM

OK - pulled flywheel off. Bad and not so bad. The flywheel has been rubbing on the two pins that hold the thrust washer in place. The flywheel is scrap (bits of the pins stuck to the back of the centre flange) and the pins are sheared off, but there is no damage to the crank case. So, I need to extract the remnants of the pins, fit new ones, put the thrust washer in place, get a new flywheel and rear main seal, and reassemble from there. First trick is to get the old pins out.. I think I'll pull the motor out of the frame so that I can get a good go at it. Frame needs repainting in any case.

FR700 · 11-06-2012, 06:18 PM

So how are you going to check the front thrust washer for condition without taking the crank out ? The crank walked forward and the odds of the front one staying in place are slim. The omission of the rear one allowed the flywheel to be tightened without binding the crank.

... if all else fails my k is sidecar ready ... I'll be getting rid of it shortly. Either sell it in one piece or break it down to small ones that fit in a rubbish bin

.

10-28-2012, 07:08 PM	#2
pommie john Beastly Adventurer Joined: Apr 2008 Location: Brisvegas, Australia Oddometer: 1,113	I'd have a look at the thrust bearing ( throwout bearing) before I pulled the 'box off. __________________ The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt. Bertrand Russell

10-28-2012, 07:16 PM	#4
disston ShadeTreeExpert Joined: Mar 2011 Location: Silver Spring, Md Oddometer: 4,980	This doesn't make sense. You kill the motor by pulling in the clutch lever, but you can shift the bike with out using the clutch lever? Actually it is possible to shift the bike w/o the clutch except for getting it out of neutral. It does sound like you had the gear box with all the throw out pieces in the trans and maybe you put this in the bike with out removing them for cleaning and greasing. You can do that now with out removing the box. Leave the long rod, #1, in place but take out the thrust pieces and bearing. It's possible you need a new bearing. If this stuff is dry and/or corroded it can destroy the transmission rear cover. __________________ Never memorize something you can look up. ---Albert Einstein

11-06-2012, 06:18 PM	#15
FR700 Heckler™©® Joined: May 2007 Oddometer: 3,459	So how are you going to check the front thrust washer for condition without taking the crank out ? The crank walked forward and the odds of the front one staying in place are slim. The omission of the rear one allowed the flywheel to be tightened without binding the crank. ... if all else fails my k is sidecar ready ... I'll be getting rid of it shortly. Either sell it in one piece or break it down to small ones that fit in a rubbish bin . __________________ I'm diagonally parked in a parallel universe .

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10-28-2012, 06:52 PM	#1
Rockman ^OP Gnarly Adventurer Joined: Jan 2007 Location: Inverell, NSW Australia Oddometer: 228	R80/7 clutch problem I am in the process of reassembling a R80/7 I got as a semi basket case. I put the flywheel, clutch and gearbox back on. All seemed well. Bike starts and runs well and at first the clutch seemed fine. Suddenly though, the cluch freeplay increased a lot, and the bike now issues a graunching noise when I pull the clutch lever and pulling it right in can stall the motor. I cant see how I could have mis-assembled it but maybe I did. If I dont touch the clutch lever all is well. It starts and runs as it should and the gearbox changes through all gears without problems. Obviously the gearbox and probably clutch has to come out, but has anyone got any suggestions as to what is going on?

10-29-2012, 04:47 AM	#6
Rob Farmer Beastly Adventurer Joined: Aug 2002 Location: Loughborough, Leicestershire. England Oddometer: 3,733	I'm not saying this is the issue but I had similar symptoms when the spot welds came away on my clutch. I only found the problem when I removed the whole clutch. If you're completely out of ideas when you've checked everything else it may be worth a look.

10-30-2012, 05:56 PM	#12
Airhead Wrangler More tacos than you Joined: Mar 2008 Location: Manzanillo MX, occasionally Seattle Oddometer: 5,090	Sounds like FR700's right then. Yikes. It might be time for a larger tear down. Pull that flywheel and see what's there... or more importantly what's not, I guess. __________________ R80ST Gets The HPN Treatment Ducati Pantah 500SL Rebuild Seattle to TDF on an airhead WTB R100R Mystic sidestand and mount.

11-04-2012, 03:22 PM	#14
Rockman ^OP Gnarly Adventurer Joined: Jan 2007 Location: Inverell, NSW Australia Oddometer: 228	OK - pulled flywheel off. Bad and not so bad. The flywheel has been rubbing on the two pins that hold the thrust washer in place. The flywheel is scrap (bits of the pins stuck to the back of the centre flange) and the pins are sheared off, but there is no damage to the crank case. So, I need to extract the remnants of the pins, fit new ones, put the thrust washer in place, get a new flywheel and rear main seal, and reassemble from there. First trick is to get the old pins out.. I think I'll pull the motor out of the frame so that I can get a good go at it. Frame needs repainting in any case.