Drive shaft - separation from the gearbox?

Gents,
Have just serviced the swing arm bearings / suspension conrod roller pins; and now need to rebuild it all. The driveshaft separated at the rear end when removing the CARC Drive - and slipping it all back in this configuration is never going to happen it seems. I need to remove the drive shaft at the gear box.... but it’s stuck fast. Right now it’s soaking overnight with penetration oil. In the meantime.... any tips pls?
I appreciate I can split the swing arm casing from the rear housing... but it seems to be (factory) assembled with some black sealant involved... so this’ll be the Plan B I guess.
As a general note, now with electric hoist in the roof (rear of bike weighs 154Kg)!), it’s been a straight forward and easy job; Pete’s tip to only grease 1/2 the needle rollers at a time a life saver.
I wasted a bloody hour asking neighbours for the 14mm Hex drive / Allen key (to remove the swing arm pin)... before trekking out to Autobahn. No luck there either. On the way home a Eureka moment to instead use a 14mm bolt head, with mole-grips on the shank. Worked a treat....
Anyways, thanks in anticipation... steering head tomorrow, and Mapping next week once I get my head around my eBay Windows10 laptop. (Aargh... been Apple for 15+ yrs ..)

The swing arm bearings were indeed dry... but ok... so glad I’ve now done it.[You must be registered and logged in to see this image.]

Don't even think about it. Just separate the bevelbox from the swingarm. The idea of trying to juggle the front yoke onto the gearbox output shaft is the sort of thing of which nightmares are made.

The shaft is retained on the output shaft by an internal circlip. Pulling on it and a heavy blow on the yoke with a hammer at the same time will pop it off but there is no point. Spray the splined area with chain lube, separate the bevelbox from the swingarm and re-install the swingarm, then the bevelbox. Really, just do it.

If your shock linkage bearings are shot just buy a new one. It's about the same price as all the bearings and pins but you don't have to rebuild it. Just grease it properly first, likewise the wishbone.

Ah, thanks Pete. I was dismantling/ rebuilding via the GRiSO Shop Manual... it gives every indication (to me) that the shaft would detach at the gearbox. No indications of circlips etc... I even looked at the parts diagrams... again, nothing wrt internal circlips. (and as a rule I’m very anti the use of hammers about my vehicles - so whacking it was never going to happen)

The bike is low miles (5000kms) and thankfully grease was more-or-less present in all bearings. All looked perfectly serviceable and has been cleaned & freshened up with new grease. Tomorrow will crack on with what you say - many thanks.

You want to pack the bearings chock full of grease. It's not so much to lubricate as to prevent the ingress of water. The pictures I often see accompanying posts where people say their bearings had grease ex-factory always seem to show hardly more than the grease used for shipping. You want the entire cavity stuffed full, it's easy to wipe off any excess when you press the bearing into its race before refitting the swingarm.

Thanks again... I washed the main ball races in petrol, dried them with methylated spirits, and as far as I know indeed pack ‘em full of grease. I’ve no grease packer tool, but did my best to vigorously massage it in with fingers a few minutes / race - hopefully all good. The needle bearings just got a direct massage of fresh grease.....

Well, that was a pig of a job. Pete, your, “ separate the bevelbox from the swingarm and re-install the swingarm, then the bevelbox. Really, just do it.” ... didn’t quite work out, as the bevel box / SA appeared to be glued together. I tried a rubber mallet..... dropped the whole swing-arm across a fulcrum rubber wheel chock... put all my weight across the above fulcrum... nothing / nada / zip. Long story short, but with last night’s lubrication the drive shaft was at least sliding on the output shaft... and a bit more grease had it popping on/off in a fairly repeatable fashion. Another bloody hour dropping the shaft down the swing arm... and bingo, I finally got it onto the bevel box drive. From there the assembly all fairly straight forward, noting that the drive shaft has indeed popped home onto the output shaft internal clip. Hopefully this job ticked off for another 10 years...

By far the easiest way to separate the bevelbox from the arm is to do it while the swingarm is still installed on the bike. Get a bottle jack and put it between the shock linkage and the ABS sensor mount on the bevelbox and gently pump it off. As soon as the box starts to separate you can work around the boot retainer Clip with a thin screwdriver to stop it sticking to the arm and deforming as the box comes off.

The box was never meant to be glued on but because there were cases of oil misting around the joint there was wailing from the moaning minnies so they started glueing them on which leads to people trying to take the swingarm off with the box attached which is not how it's supposed to be done and makes the whole operation about a million times more difficult than it is.

Thanks Pete... certainly made for an interesting/ infuriating afternoon! On the plus side the seal, unbroken, didn’t need cleaning / resealing....

I hope you're 100% certain the front yoke is being held by its circlip correctly. It'll be a costly and dangerous mistake if it isn't.

I really, strongly, counsel others NOT to remove and reinstall the swingarm and driveshaft this way.

Thanks Pete... it was uppermost in my mind to double-check the circlip had locked. The thing that bothers me most here, is that I was working from a Moto Guzzi Service Station Manual, and followed their instructions to the letter. No such warnings as yours above, no mention of separating the bevel box from the swing arm etc. The comprehensive photos / writings all show the swing arm / bevel-box being removed and replaced as one unit. What gives.... ?

Outta interest, what is the costly danger if the ‘shaft were not installed back onto it’s circlip? Surely it’s contained be virtue of its length and it’s boundaries of slip...up and down the fore / aft splines. IF it weren’t on its circlip, would the first suspension action simply push it into position?

Confused...

Without the shaft being properly retained it will slip backwards. The sliding movement, supposedly controlled by the locked front yoke, will result in low engagement of the front splines And the rearmost yoke grinding, like a poorly designed lathe tool, on the throat of the bevelbox seal holder.

Eventually you would get to the point where enough metal had been ground away from the seal holder that there would be either too little spline carrying the load at the front and it would strip, or it might get spat off the gearbox output shaft and shatter the swingarm.

I wouldn't want to be on the bike when that happened.

As to the manuals? It is stated that all Piaggio service manuals, and before them Aprilia and Guzzi SPA manuals that a level of knowledge and competence is expected. This isn't to say you are incompetent but it DOES mean that you are expected to have a basic and intrinsic understanding of 'How shit goes together and works'. Taking stuff apart should be done intuitively. "How do I get to this bit? Well, I take this bit off!" The greatest challenge faced by the average home mechanic is that they will not follow this maxim and will spend enormous amounts of time and effort making a simple task difficult! Often breaking stuff or tying themselves in knots rather than just following the obvious path.

An example I'm afraid is your statement that you don't like hammers near your vehicles. Sorry, but removing the driveshaft is a task that a hammer makes very easy! It's a tool! It has its place and uses. Just because it can be used inappropriately doesn't mean it's the wrong tool for a job that requires a hammer.

Be logical and methodical. It works out better in the long run.

Sorry I cannot comment on the shaft separation issue but I sure see a lot of interesting equipment in use for a novice mechanic. The crane pendant hanging in the picture suggests an overhead crane/hoist and a digital weight scale are rare finds for a novice tool kit. The rear of the bike is not heavy but the S hook that is holding the slings to the weigh scale appears ready to fail.
My typical comments for issues as these are to control your frustration. Frustration management is the key to assist in new typically skilled trade repair adventures and avoiding errors in judgement.
The 'Old Farts" advice is relevant, valid, speaks of much experience and is entertaining for sure.

Huh? The S hook is rated at 500Kg, and is nowhere ready to fail. But thanks for the novice observation...
Move Dirt, with due respect you know nothing of my workshops experience, qualifications, skills etc. Trust me, I’m not frustrated either.
The problem I do have however, is when Service manuals are be at odds with common practices, I quietly gave up & didn’t bother to actually post the relevant pages on shaft drive removal / replacement... but it is black and white - with pictures - that they are done as one unit, and upon replacement, you mate the drive shaft into the gearbox out put shaft. Quote... ”Insert the universal joint, align the (swing arm pin) holes, and helped by an operator at the same time, insert the swing arm pin”

The manual does say to remove the swingarm holus-bolus. I think some slack should be cut.


[You must be registered and logged in to see this image.]

...thanks Beetle.

Guzzi has a long and illustrious history of 'Recycling' bits of old manuals into new ones. They probably just took some new pics and used the old Tonti frame instructions! In all honesty I've never read that part of the manual. It all seemed so straightforward that no instruction was needed.

Really though, for the benefit of others, I think your post is a useful and salutary lesson in why it's best not To do it the way you did. I mean? How long did it take you? Trying to juggle the yoke on the bevelbox end of the shaft into engagement on the pinion splines. Then trying to hold the whole bevelbox/swingarm assembly and juggle it into place and then the faffing about trying to ensure the front yoke was secure n the output shaft! It must of been a nightmare! I can feel my scrotum shrivelling just thinking about it! And trying to insert the spindle without knocking the seals off their registers in the frame? Oh boy!

Look, I'm glad you succeeded, but really, separating the box takes the removal of four bolts and either accurate belabouring with a rubber mallet, (Michael has a 100% success rate with this. Mine is more like 50%. It also depends on the amount and age of the silastic in the joint of course.) or my trick of levering it off with a bottle jack between the ABS sensor mount and the shock linkage. It actually takes very little pressure. It's breaking the initial seal that is the embuggerance.

Once the box is off though the job becomes absurdly easy. The swingarm is really very light, all the weight is in the bevelbox. You can slip the spindle out and slide the swingarm off the shaft and as long as the bearings don't need replacement you don't even have to remove the shaft. You can pluck the bearings out, even the right hand side one, and re-pack them without removing the shaft. The front splines can be simply be given a good spray of chain lube to protect them. It penetrates really well and the whole point is to protect them from oxidisation, not to lubricate them per-se.

Reassembly is likewise easy and simple. Without the mass of the bevelbox on the end of it the swingarm is an easy, one handed, job to manoeuvre into place and can be manipulated delicately, along with the spindle, to avoid the risk of knocking the seals off their registers in the frame. The linkage et al can then be easily positioned and installed without the strain of having to control the mass of the bevelbox and finally slipping the bevelbox back on to the driveshaft and bolting it in place takes five minutes! My guess is that the whole operation would probably of taken not much longer than the hour you spent trying to drop the shaft down the swingarm to engage on the pinion splines.

I will reiterate once again, I'm really glad you got the job done. I'd just like others to realise that you made it much, much harder for yourself and introduced a number of risks that can be very, very easily avoided by simply adding one simple step early on in the procedure and separating the bevelbox from the swingarm.

Regarding the "S" hook.
Rated 500 KG (1100 lbs) on an S hook?
An "S" hook does not have a safety rating or is ever safety rated for a load, anywhere in the world. An "S" hook is not a rigging device. A "S" hook could be used to hold up a garden hose, an electrical cord or to hang your slings up but is never to be used to hold any weight safely.
That said, the remaining comments that I mentioned were in appreciation of your fine tools. You even used a piece of ground and polished shafting to support your frame while resting on a very fine, exotic looking stand. Regarding the word "Novice". A novice would not have access to or own very fine tools that are typically somewhat exotic for any one to possess for a at home repair. That clearly implies that you are not a Novice and have a technical back ground. We are all not aware of others back ground. The only TELL for me of your background experience is that you would use a manual and be distracted by it. Nothing more.

'Snot an S hook, but a butcher's hook - used on farms all over Australia to string up anything from a whole beef, to fencing wire AND everything in between!


OK I'm not being helpful, so I'm going.

There!

[You must be registered and logged in to see this image.]

Actually thinking about this while driving around this arvo perhaps the reason why removing the entire assembly was originally considered is because on early bikes the bevelbox wasn't glued on so it was easy to separate when off the bike.

I still think it's daft and I'd never of thought of doing it that way but it might explain the thinking behind the way it's suggested in the book. Certainly breaking the seal is a lot easier with the swingarm still mounted to the bike.

That butcher’s hook... it is part of the (Australian made) hoist weighing scales package, whose limit weight is quoted at 500Kgs. I am 100% happy that it handles 154kg of Guzzi back end safely given it’s obvious build quality... but genuinely Move Dirt, you should write Gorilla Hoists if you personally think there’s a safety issue here. (1/1 Federation Way, Chifley Business Park, Mentone, VIC, 3194)

I’m absolutely confused by your comment, “The only TELL for me of your background experience is that you would use a manual and be distracted by it”.... that word DISTRACTED .. seriously?
I’ve owned Hondas / Yams for years, know my models inside out, and yet still pull the manuals often... because I don’t perform certain tasks on a weekly basis...
such as removing a bloody swing arm assembly!
Are you inferring manuals are only for the uninformed / incompetent/ under confident types? If so... cripes. My working life revolved around manuals, I’ve used more than you could poke a stick at, and even written some. Where a manufacturer publishes one, they are typically NOT for guidance / information only, but rather a definitive way of performing a particular task in the most safe and efficient manner. If one chooses to deviate away from the manufacture’s procedures, well fine (though not in my particular job), but if it came to an accident / court of law you’d be on very thin ice. Summing up, manufactures manuals should be the first go-to source / point of reference; and have to be assumed as accurate as written by the very folk who designed the equipment you’re using.

Pete, removing the complete SA assembly was easy, but now I was in the position of NOT having it on the bike to break the seal via a bottle jack. I gave it a fair go via other methods. This all said though, I’d be a lot quicker 2nd time around (with bevel box attached) as I’ve learned the ‘tricks’ - a lot of time was wasted making measurements where the UJ would engage, realising that the waistline shape of the SA would prohibit certain ‘drop angles’ of the cardan shaft ... and so on.
Furthermore, by breaking the BB / SA seal I’d have that clear-up to deal with, and thence a re-sealing - this would have taken a significant time to do properly (I guess).

As for your concern of the output shaft clip, I cannot see how (once bolted up) the shaft is not safe as the various lengths / measurements appear to disallow the situation of your concern. It is easy enough to check by pulling back the bellows - and even wiggling the shaft up & down with a screw driver - but (in my case) there were only 2mm or so of output shaft drive splines left exposed; the cardan shaft was as forward as I’d want it to be...

Move Dirt, genuinely not looking for an argument here - you simply intrigued me and so I had to go look it up....
S hooks definitely are load rated; well the myriad I saw for sale on the internet at least. Below a pic of the FIRST google entry, all subsequent offerings with load ratings too.
Cheers.[You must be registered and logged in to see this image.]

Pics You will not find in the manual - hope it helps: You will see the clip, the clips groove and how to remove the shaft (by twisting the screwdriver).

Thanks v-M, and always better with photos. Yep, the twisting screwdriver ploy (though I simply levered a small 1/4” drive head against the output shaft end) worked a treat in popping off the forward yoke. Don’t plan to be in this part of the bike for a while now!