How to remove "Clutch Gear" aka "Clutch Hub" aka "Transmission Input Hub"?

[usedtobefast]

This is on a 2000 Quota 1100 ES. 

The front transmission seal is leaking, so I need to remove the "Clutch Gear" to then get to the seal.  I did several searches but couldn't find any tips/hints on this.

I bought the "Clutch Hub ring nut tool" from MG Cycles ... they suggest using an impact wrench to remove it.

But how do I keep it from spinning?  I hate the idea of putting it in gear, having an assistant stand on the rear brake peddle, and then hitting it with an impact wrench!

I currently have the motor out, rest of bike is together ... so the transmission, final drive, rear wheel, etc are still together.

It is #3 in this pic:






So what are the tricks for removing this?

Thanks!

[Antietam Classic Cycle]

Use an old clutch plate to make a tool to hold the hub, bend the locking tab down out of one of the notches, then use the impact and socket to remove the ring nut. No old clutch to make the tool from? I can send you one.

[usedtobefast]

Use an old clutch plate to make a tool to hold the hub, bend the locking tab down out of one of the notches, then use the impact and socket to remove the ring nut. No old clutch to make the tool from? I can send you one.

Ah, I do have an old clutch plate.  Any suggestions on how to turn it into a holder?  I assume that bolt is a fairly high torque bolt? 

[pehayes]

Something like this.  Just a piece of flat bar welded to the clutch plate center.  Could be bolted if you can't get a welder.

Patrick Hayes
Fremont CA

[Kiwi_Roy]

Ah, I do have an old clutch plate.  Any suggestions on how to turn it into a holder?  I assume that bolt is a fairly high torque bolt?

Just drill a 6mm hole somewhere on the circumference then use a few inches of strap to connect it to one of the flange bolt holes (under tension)
No any old MS bolts will hold it with that leverage, I just used 3/4 x 16 gauge aluminum strap.
Same again when you put it back together, I bolted the gearbox flange to an 8ft 6 x 2 to hold it firm while I torqued up the nut.

[Rolf Halvorsen]

If you can see gear oil  residues on the front of the gearbox - then it might be the front sealing ring.

If you have gear oil inside the clutch - then it is the 2 small conical seal for the push rod (can be changed from the back of the gearbox.

Rolf

[Old Jock]

Great tip from Rolf about the pushrod O rings

If it's dripping smell the goo, you can easily tell transmission oil from engine oil

Patrick and Charlie's advice are spot on though it's not a biggie to place the box in gear and restrain the output shaft IF you use an impact, as that just whizzes it off. As already stated but emphasized MAKE SURE THE LOCK TAB IS BENT UP FIRST (you'll be in for a very hard time if its not, ask me how I know)

Sometimes the Hub just won't budge and you'll need to open the box which is no biggie. I don't think I've ever tried to replace that seal with the shaft in place but can't see any reason that it's not doable.

Stein Dinse in Germany and probably a lot of other places sell a hub holding tool, but Patrick's idea is just as good and cheaper

If you've never been into the box now is a good time to replace seals and O rings etc: it's not complex in fact the tab nut is the hardest thing to get off if you don't have the right tool. You can go at it with a chizel, but be warned if it doesn't move and you mash it, it's not good.

I often post up my link to the 5 speed box strip that should take some of the mystery away (if there is any)

http://www.thisoldtractor.com/guzzitech.dk/gb_en_complex-technical_gearbox-rebuilding-pictures.htm

John

[Chuck in Indiana]

they suggest using an impact wrench to remove it.

Don't even *think* of not using an impact wrench. You'll take the drive lugs right off the tool without one.

[Groover]

I heard that there is a live strream going on right now about to cover that exact step 


https://wildguzzi.com/forum/index.php?topic=104253.0

[Antietam Classic Cycle]

If you can see gear oil  residues on the front of the gearbox - then it might be the front sealing ring.

If you have gear oil inside the clutch - then it is the 2 small conical seal for the push rod (can be changed from the back of the gearbox.

Rolf

I know the conical seals are supposed to be an "upgrade", but I found them to still leak. I use six of the special sized o-rings that Moto International used to sell. I'll send anyone that wants some a baggie of six for free.

[Wayne Orwig]

I use a bar welded to an old clutch plate as a holding tool. Drill and punch the old nut off. Replace with a regular hex nut per instructions from MG Cycle.

If the seal is leaking, make 100% sure that you don't have a bearing failing.

I was told by a long time mechanic once to never use an impact wrench on the tool, as it will damage the tool.

[usedtobefast]

Something like this.  Just a piece of flat bar welded to the clutch plate center.  Could be bolted if you can't get a welder.

Patrick Hayes
Fremont CA

Ok, thanks for the picture!  No welder, but I think I can rig up something like this. 

[usedtobefast]

If you can see gear oil  residues on the front of the gearbox - then it might be the front sealing ring.

If you have gear oil inside the clutch - then it is the 2 small conical seal for the push rod (can be changed from the back of the gearbox.

Rolf

The back of the engine is the big leak, engine oil pooled up all over the place ... I've found lots of great info on how to treat all the suspect areas there ... so I think I have that figured out. 

The bell housing / front of the transmission also has some oil residue and it does appear to be coming from that front seal on the transmission. 
And oil on the clutch plates too.

I also got all the wear items (o-rings, conical seals, thrust bearing) for the push rod so I'll be replacing all that too.

[usedtobefast]

If you've never been into the box now is a good time to replace seals and O rings etc: it's not complex in fact the tab nut is the hardest thing to get off if you don't have the right tool. You can go at it with a chizel, but be warned if it doesn't move and you mash it, it's not good.

I often post up my link to the 5 speed box strip that should take some of the mystery away (if there is any)

http://www.thisoldtractor.com/guzzitech.dk/gb_en_complex-technical_gearbox-rebuilding-pictures.htm

John

The bike has 21,500 miles on it, so I'm hoping the transmission is all good.  It shifts well (for a MG) and no issues there. 

Thanks for that link!  That really shows the push rod very clearly and all the parts, very helpful!

[usedtobefast]

I use a bar welded to an old clutch plate as a holding tool. Drill and punch the old nut off. Replace with a regular hex nut per instructions from MG Cycle.

If the seal is leaking, make 100% sure that you don't have a bearing failing.

I was told by a long time mechanic once to never use an impact wrench on the tool, as it will damage the tool.

The tool I bought from MG Cycles says on their website to only use an impact wrench.  Here is their info "This tool should be used with a half inch drive impact wrench while held squarely against the nut requiring removal. If used inappropriately, such as by hand with a breaker bar or other extension, it is possible to apply force other than perpendicular to the tool axis which can place excessive force on individual tool tangs resulting in breakage. "

Thanks for the bearing check idea ... the bike has 21,500 miles so I'm hoping/thinking that it is just seals that are old and that bearings are still good, but will check that.

[Don G]

 I never used a tool to hold the clutch hub, wrap a rag around the hub and grasp it with your other hand and fire away with the impact, the nut will come right off if you have a real impact tool.  DonG

[Antietam Classic Cycle]

I also got all the wear items (o-rings, conical seals, thrust bearing) for the push rod so I'll be replacing all that too.

I know the conical seals are supposed to be an "upgrade", but I found them to still leak. I use six of the special sized o-rings that Moto International used to sell. I'll send anyone that wants some a baggie of six for free.

[Old Jock]

I do agree with Don G there is not much force on the box if an impact is used

Just to add its in the write up, but if fitting replacment the bearings the large bearings on the clutch and layshaft are better replaced with the all metal twin row type, that's if they are the single phenolic/nylon cage model

John

[usedtobefast]

Success!! 

I had an old aluminum bark buster from a dirt bike that looked like it was made for this.  Drilled a couple of holes in an old clutch plate, bolted it together.  Tapped all the points of the star washer back. 

I was still a bit freaked out about holding my new tool while spinning up the impact wrench ... like what it it slipped out of my hand and went spinning around ... so I worked out a way to block the holder tool in place (strategically placed old plastic "milk carton") ... took a deep breath, and pulled the trigger ... came off easy peasy! 

Time for lunch and then ride the other 2 working Moto Guzzi's a bit.       Thanks for the help!

My hasty made tool:

[Groover]

Great job, looks perfect! I do have a question, do you guys think one of these things would do the trick? I know it's rubber, but I've used them (not exavtly that set, but equally hefty) to hold some pretty tight stuff.





Just wondering.

[Antietam Classic Cycle]

I never used a tool to hold the clutch hub, wrap a rag around the hub and grasp it with your other hand and fire away with the impact, the nut will come right off if you have a real impact tool.  DonG

But you still need to hold the hub when reinstalling. Might as well make the tool since it usually doesn't cost anything.

[malik]

I had these made up for the V7. The principle should be the same, just a different clutch centre. The guy who made them for builds roll cages for living, so over-engineering is the norm for him. The Z bend is so they fit flush inside the bell housing.





To hold the flywheel, I either use a socket on the alternator nut with a long bar against the floor, or this flywheel holder (from a VW toolkit - borrowed from a Porche enthusiast).







Don't have a big block, so not sure it works, but something similar should.

Mal

[pehayes]

Great job, looks perfect! I do have a question, do you guys think one of these things would do the trick? I know it's rubber, but I've used them (not exavtly that set, but equally hefty) to hold some pretty tight stuff.

Just wondering.

Likely not.  The whole idea of the impact wrench is to transmit very short bursts of torque.  Using a rubber holder will act like a shock absorber.  The impact gets received and relaxed and nothing gets transmitted to the rigid part.

Patrick Hayes
Fremont CA

[usedtobefast]

Ok, another question ... what torque should the bolt/nut go back on at? 

MG Cycle calls this the "Ring nut, transmission input shaft" ... I looked through a few MG torque tables and can't match up the wording/lingo. 

I have a new lock/tab washer, but would like to know a torque value better than my "nice & tight" setting.   

[Chuck in Indiana]

Ok, another question ... what torque should the bolt/nut go back on at? 

MG Cycle calls this the "Ring nut, transmission input shaft" ... I looked through a few MG torque tables and can't match up the wording/lingo. 

I have a new lock/tab washer, but would like to know a torque value better than my "nice & tight" setting.   

Rattle gun it on. Don't have it set for 200 foot lbs.  Bend over the lock tab and forget it.

[malik]

In the small blocks' workshop manuals it's called the "clutch shaft fixing nut" and the torque is 100 Nm or 73.76 ft/lb - which means, because I haven't figured out a way to get a torque wrench socket over the nut while holding the shaft with the special tool, means hard enough to threaten a weep at your other end, before punching the tab.

In the manuals I know the tightening torques are listed in two places - one in the Tightening Torques section near the front (it's the only entry under "Clutch", and in the exploded diagram  of the clutch in the section devoted to that part of the bike.

Hope that helps some. Lost my big block manuals when I pruned the space needed for the the last operating system update.

[Antietam Classic Cycle]

Ok, another question ... what torque should the bolt/nut go back on at? 

MG Cycle calls this the "Ring nut, transmission input shaft" ... I looked through a few MG torque tables and can't match up the wording/lingo. 

I have a new lock/tab washer, but would like to know a torque value better than my "nice & tight" setting.   

The factory spec. is 108 ft. lbs.