Clutch noises on sporti

[bigpants]

Thanks very much for that jock. I was going to make a compressor from an m10(fine) bolt . But I guess no matter what I find in there I'm going to need an alignment tool to get it all back together anyway so may as well bite the £40 bullet. I cant help wondering though , I've got this far , and I hope to never be here again , but my engine is old , must be 100k miles. It's never had any rebuilds or anything. Should I do more here than just fix a broken clutch ? Just seen the post from Wayne. I'll get some better pictures up.

[Old Jock]

Only you can really answer that question, I don't think there is much more you can do maintenance wise unless you decide to open the Gbx or the engine. Besides it looks like you got it apart in a day, Wayne is eagle eyed I never noticed the hub marking, it is bit difficult to tell from just a picture.

Wayne is more knowlegable than me so I'd defo go with what he tells you.

I feel your pain if you need to replace it

Getting that hub off is a bit of a pain and as I remember its got the fancy notched nut on it that needs a special tool to remove it. The torque value is somewhere around a zillion into the bargian as the box relies on that and the layshaft nut to position the shafts.

It's up to you but tempting as it is to take chisel to it, that could easily end up in tears. What you need is the proper tool and a whacking great rattle gun to get it off.

[Chuck in Indiana]

^^^ yeah, not good. MG Cycle has a "kit" with clutch plates, intermediate plate, and transmission input gear for a reasonable price. Once you pull the flywheel off, you'll most likely find that kit is what you need.

[Tom H]

Since your in there........

The input splines don't look the best. I would consider a good used or new one depending on you budget.

Clutch plates. Need to see the wear and how the teeth look. Iffy, replace.

Trans front seal.

Rear main seal in engine bearing carrier.

Also see if the engine rear bearing carrier gasket is leaking.

These are things to look at since your in that far. You could leave some alone, or replace for peace of mind.

Tom

[Wayne Orwig]

I'll get some better pictures up.

That picture actually looks pretty good. Just the normal 'clean spots' on the splines.

Test the front (and rear) transmission bearings as best you can. Those plastic caged bearings are a weak spot too.

[bigpants]

Big thanks to everyone for their input. I've just ordered an m10 fine bolt that hopefully will get the old clutch apart and I'm not going to buy anything till I see what's in there. But I do have one final question for now - the clutch alignment tool seems to be £68 ($85) over here. If I bought a complete clutch kit with the new clutch hub boss , could I use that as an alignment tool with the help of a bolt and some washers ?

[rutgery]

I don't have an answer for you regarding using a clutch hub boss as an alignment tool, as I don't know if you can tention the springs using a hub boss.
However, if you've got access to a 3D printer a 3D printed alignment tool could also be used. This is what I did for my clutch replacement and it worked perfectly.
Others have used turned a piece of wood with drills to align the clutch splines as well.

[Old Jock]

Those plastic caged bearings are a weak spot too.

Believe Wayne is referring to the Gbx Clutchshaft (input) & Layshaft (output) bearings inside the gearbox (let him come back or let someone else confirm) they're the only ones I know about

If you are thinking about going into the box it's not as difficult as you might think.

The only hard bits are getting the nuts off the Layshaft and Clutchshaft, which are both torqued to high values.

If you are thinking about it, even just for a look to reassure yourself, then I'll once more do a self promotion job, as nobody else will promote me  and mention a gearbox guide I wrote a long time back.

It's really for the older 5 speed box but the main pieces are almost identical (there are some differences)

If you want it you can find it here
https://www.thisoldtractor.com/guzzitech.dk/gb_en_complex-technical.htm

Mine is the Gearbox Rebuilding with Pictures but I'd also download Pete & Rolf's Gearbox Shiming with Pictures as well

Oh one more thing if your going to go near that Clutch hub, remember it has a locking tab washer on the nut. Remember to get the tab knocked up before attempting to undo the nut.

[Chuck in Indiana]

Have no fear to go into the transmission with Old Jock's tutorial in hand.
How's that for promotion? 

[Old Jock]

 

Have no fear to go into the transmission with Old Jock's tutorial in hand.
How's that for promotion? 

 

[Tom H]

Big thanks to everyone for their input. I've just ordered an m10 fine bolt that hopefully will get the old clutch apart and I'm not going to buy anything till I see what's in there. But I do have one final question for now - the clutch alignment tool seems to be £68 ($85) over here. If I bought a complete clutch kit with the new clutch hub boss , could I use that as an alignment tool with the help of a bolt and some washers ?

Yes you can. That's what I did when I went to the deep spline.

Tom

[bigpants]

Thanks again everyone , those little bits of encouragement really make a difference.  I think having gone this far , and received this much advice , it would be rude of me not to peek under the skirt of the gearbox. I have a very competent mechanic within walking distance if needed , he has at least three different hammers. And last year I had to tinker with a box when I split the cases on my honda rs125 and all the cogs slid off the shafts onto the floor , shims and all. When I rebuilt the 6 speeder I had 5 gears and 2 neutrals.

[bigpants]

Just wanted to post this picture for a second opinion. The bell housing on the gearbox side is a bit wet , not soaked in oil but a thin film and within that film a red powder . Not sure if the red is rust or clutch. I'm guessing it's all supposed to run dry , would you say this thin film is normal enough?

[Old Jock]

Difficult to say from a picture, but it doesn't look bad to me, the red powder most likely is clutch friction material, there may be a weep from the seal but it still seems to have being doing a pretty good job

Look and feel around the rear of the hub and the seal itself to see if you can ascertain if there is any dampness, or signs of leakage and that should give you clue.

Any smell off the thin film Gbx oil has a distinctive smell?

That said if you do plan on going into the box anyway if it was mine I'd be replacing seals and O rings as matter of course as their materials tend to decay anyway and they don't cost much.

Just my opinion let's see what other wiser heads have to say

[Wayne Orwig]

Just wanted to post this picture for a second opinion. The bell housing on the gearbox side is a bit wet , not soaked in oil but a thin film and within that film a red powder . Not sure if the red is rust or clutch. I'm guessing it's all supposed to run dry , would you say this thin film is normal enough?

Sort of normal clutch dust and a film of goo.
The clutch pushrod and (I assume) transmission seal aren't dripping wet, correct?
Have you verified that the front transmission bearing feels solid?

[bigpants]

Ok , so I got the whole GBX out this morning and took it up to my trusted old fashioned bike mechanic. He had a quick look at the clutch boss with a view to removing it using just elbow grease and said it felt like it would break his homemade castle socket before it shifted. It was his opinion that the front bearing and seal seemed fine. The level of oil mist was insignificant especially as all the rotating bits were dry and there were no signs of oil fling. I'm now hoping to get into the clutch but dont have the spring compressor . I've loosened each cap bolt a turn each and tempted to keep on going but I dont want pull a thread or damage anything else. I do have a bad habit of rushing just for the sake of it.

[bigpants]

Forgot to say,  clutch pushrod dry .

[Tom H]

If your in a hurry to get the clutch plates out. A bolt and washer will push the pressure plate in and take pressure off the plates.

To install them, I would wait for a complete plate set with the hub (use it to align the plates and hold the pressure plate down) or just buy the tool.

Tom

[n3303j]

Ok , so I got the whole GBX out this morning and took it up to my trusted old fashioned bike mechanic. He had a quick look at the clutch boss with a view to removing it using just elbow grease and said it felt like it would break his homemade castle socket before it shifted. It was his opinion that the front bearing and seal seemed fine.

That nut is tight and requires a lot of foot pounds to remove. It is too easy to cock the castle wrench, unevenly load the pins and snap one or more off.
I bought the MG Cycle tool and glued (Loctite RC680) an aluminum plug inside the body. I tapped the aluminum plug for 10-32 thread rod. I remove the clutch pushrod and pass the free end of the thread rod out the back of the transmission. I cap it with a big fender washer and a 10-32 nut. This holds the castle wrench firmly in its slots. Then I break the nut loose and also loosen the 10-32 nut on the thread rod. Reverse procedure for reassembly.

I was under the impression that the transmission input and output bearings had plastic ball retainers that would disentigrate with synthetic oils. Therefore unless you were 100% sure the transmission never saw synthetic oil you should replace both bearings as a matter of course. 123bearing does have the double row, 22 ball bearings with the stamped steel ball retainers.

[bigpants]

Things have slowed down a little but that's good because I was definitely rushing. An m12 1.5mm thread 90mm bolt turned up this afternoon  and I just pulled the clutch. Both friction plates were down to 7.25mm and on one of them the friction material is a little loose , I can rotate it 2 or 3mm.  I'm hoping that is the source of the noise. It looks like my friendly mechanic is extremely busy and wont be able to look at the clutch hub for a week or two so I'll get ordering the bits in preparation.

[Chuck in Indiana]

Sounds like you found the smoking gun..

[Wayne Orwig]

on one of them the friction material is a little loose , I can rotate it 2 or 3mm. 

Bingo.

I'm sure that clutch hub is fine. Sorry I mentioned it but on the one photo it looked badly worn.

MG Cycle in the USA sells clutch plates that are riveted AND glued. I have had good luck with them. Made by SD-Tech and I'm sure available in Europe.

[leroy_can]

 Hard to say re: hub splines from a picture but if you get the M G kit and come up with a tool I would use the new hub with the new plates so a partially worn hub doesn't  cause quicker wearing of the new plates. 30 or more years ago I did my first disassembly  of my LMIV and had to make several tools to do the job. Sucked the first time but have used them enough times now to be worth it. I will try to post photos of my tools shortly to give you some hints. Some are needing machining and welding skills but not all and some leftovers you have are essential for some of them. Old Guzzi parts used in my tools are: the clutch hub, the splined  flange from an old plate, and a driveshaft coupler. I should be able to post pictures tomorrow with a bit of an explanation. It was long ago but I recall exchanging the pressure plate bolts 1 at a time for longer ones so I could back them off enough to release tension with no spring loaded surprises. If you find yourself with a chisel and hammer in your hands count to ten and take a break. You can't properly put it back together with a chisel but I'm sure it has been done.

[leroy_can]

  Here are my tools hopefully this will help.
    !st is the plate with the center spline of an old clutch plate attached. With this you can: 1-hold the clutch gear while torquing the ring nut on the trans input shaft, 2- hold the flywheel from turning while torquing the bolts holding it to the crank, 3-hold the flywheel while torquing the cam gear nut and the crankshaft gear nut.


upload pic

    The next is a worn hub used to center the plates and also compress the springs. It appears I cut the gear down some but probably because the bolt I had needed to be longer otherwise. You can also see how it is centered with a bushing.




   Then there are the 4 long handled wrenches I made,








    One has 1/2 of an old driveshaft coupler welded to it which can either hold the trans output shaft spline or hold the pinion shaft spline from turning while torquing. If you were doing the rear drive pinion you would need a 36mm box end for the hex nut.
   The next is a 27mm socket welded to a handle. This size fits both the trans output shaft nut and the camshaft gear nut. It needs to be open ended as shown so the tool that holds the spline on the trans shaft fits inside it.
   The last 2 are sockets I modified to engage the 2 different sized ring nuts on the trans input shaft and the crankshaft gear.
    Not all that easy to do depending on your skills and equipment but this gives you a starting point. You would quickly spend more paying a shop to do the work. Talk to other owners as everyone with much mileage has had to do these jobs and the same tools would cover a wide range of years.

[bigpants]

Thanks very much everyone for all the input. Looks like I'll be using the old bits to make some new tools , recycling the guzzi way.
There was a time my bedtime reading might extend to penthouse magazine or if the student loan hadn't come through 'readers wives' , now its  all 60 pages of old jocks gearbox rebuild , it was just as stimulating and as soon as I can get that hub off I'll get in there and at least refresh the bearings and oil seals. But I am wondering , what's on the other side of the the clutch ? I guess I'm looking at the flywheel now , held on by 6 (or so) bolts. Now behind that there must be an oil seal , so my question is can that be replaced from this side  ?

[Chuck in Indiana]

so my question is can that be replaced from this side  ?

Sure can. You may have to get creative with sheet metal screws and a tack puller, etc. but it can be done. Might as well do the "while you are theres.."  including the epoxy the freeze plug, etc.

[bigpants]

Err , epoxy the freeze plug ? I've no idea what that is and searches didnt reveal anything except some X rated images I can never unsee. Please enlighten me.

[Old Jock]

I "think" that the Freeze plug is a reference to the cam plug which is at the top of the crankcase, once you've got the flywheel removed, it's obvious. Apparently they are famous for leaking and can be covered with JB Weld or Epoxy to prevent it.

See This Old Tractor article Ok that's for other models but it applies to all Big Blocks (and perhaps Small Blocks I don't know)

Scroll to the bottom picture to see one that's been JB welded

https://www.thisoldtractor.com/moto_guzzi_loopframe_engine_out__check_these_things.html

Gearbox Guide as stimulating as "Reader's Wives"????

bigpants you're seriously needing to get out more 

[Chuck in Indiana]

I see old Jock has beat me to it.  Here's a picture of the freeze plug with epoxy applied.

While you are there..  is a good time to *really* look to see if there are any possible leak sources in the next 20 years or so..You'd hate to put it all back together and next year find a drip coming out of the bell housing from one of those 40 year old gaskets.

[bigpants]

Yeah , there is the strong temptation to put in a clutch , hope for the best and go for a ride. But as you say it would be silly to do that . It's the going into the unknown that is scary , in terms of the amount of things I could do wrong and the potential expense. I wish I hadn't cleaned the crank side of the housing now , it was wet like the other side and wouldve been good to get you people to look at it. I never realised there was a tell tale at the bottom either and I cant help wondering if this build up of crud is because I couldnt get to it to clean it or build up from the tell tale.