Wildguzzi.com
General Category => General Discussion => Topic started by: yackee on October 03, 2022, 04:54:31 PM
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Hi all,
Some of you kindly responded to my earlier post about my clutch slipping. I am now wondering if I have bigger problems. I did the mineral spirit flush, and drove without incident to the grocery store. Clutch was working fine. But by the time I got home, I was getting a very noticeable but intermittent high-frequency vibration through the right foot peg that travelled through my doc Martens to my foot. It was like a focused foot vibrator massage. The vibration would last a few seconds, then stop. I took the bike out again today to the store and was now getting a noticeable grinding noise that sounded like it was coming from below my rear end somewhere, along with the vibration. This is happening at low speeds and is not constant but intermittent. I am now a bit worried about taking it up to highway speed. There is no vibration from the left footpeg, whatever is happening is very isolated. The grinding sound has me especially worried.
I am not saying this has anything to do with the mineral oil flush, maybe its part of whatever was making my clutch slip? I did check and replace the gear oil in the front part of the drive; I had plenty, and it looked very clean.
Any thoughts?
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Not wishing to cause fear or distress ,but the way you describe it sounds like a universal joint or it's support bearing in the swinging arm.
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with what symptoms you describe, I am suspecting the "U" joint. I have read of vibration in the right peg/floorboard could be indicative of a failing U joint, or bearing it rides on. To inspect that would require you to remove the swing arm. If its just the bearing, its inexpensive,and relatively easy to replace.
Rick
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^^^^ What they said.
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U-JOINT plus probably carrier bearing. Don't worry, I left Boston for Prince Edwards Island with my girl friend on the back back of my Eldo in 1980? and had a couple of momentary lockups, ignored. New to Guzzi, I didn't notice vibes. Was off road in Canada. Got home, swingarm off, u-joint fell out of chamber in 2 pieces...
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When asking a question bike year and model is always handy. :)
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When asking a question bike year and model is always handy. :)
Sorry, indeed I forgot that. 1976 t3, I believe original u-joint, but if replaced, at 25k miles or so. Has about 50k miles.
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Well the difinitive test is to ride along and when you detect the vibration, change gear. If the vibration stays the same, it’s from the gearbox output shaft or further back..(the shaft rpm stays the same if you have not altered speed, even though the revs have..).
If it does alter with rpm, then it’s the input shaft or forward.
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I'm with all the others, that through personal experience would be tempted to suggest you
get at that cardan joint (U-joint) asap . There is no roadside repair for that :( . Peter
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The next step is feeling it spinning through the peg.
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Maybe check the swingarm pivot pins to make sure that they have not loosened up? If the swingarm gets out of adjustment is it possible for something to make contact? Better minds than mine can think this through. If it were a Commando I would say the layshaft bearing is going.
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I had a ujoint carrier bearing come apart at around 60 mph on I 220 around Shreveport on a Cal2 in traffic.The back tire suddenly stopped. It then unlocked, repeating locking and unlocking as I slowed. Clutch didn’t make any difference of course. Destroyed swingarm. It was exciting. I wouldn’t ride yours over 20 until it’s fixed.
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I'm with all the others, that through personal experience would be tempted to suggest you
get at that cardan joint (U-joint) asap . There is no roadside repair for that :( . Peter
I'll very much second that. I had a UJ go on me at a 80mph plus on the motorway years ago...and it was not giving any detectable signs of failure.It was my lucky day as I managed to coast the bike from the third fast lane to a lay by without locking the rear wheel and I didn't fill my pants either !!! Someone up there was looking after me.
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Yup grinding noises are usually suspicious… :shocked:
On the centerstand in neutral just rotate the rear wheel slowly by hand…see if it hits a tight spot
New ujoint is a press fit into a new carrier bearing
Mufflers off
Remove lower shock mounts
Axle out
Remove rear wheel with rear drive attached holding the open end up so gear oil doesn’t coat the driveway
Remove swingarm pivot pins
Establish the bike is secure from rolling forward
Wrestle swingarm out
Ujoint falls to the floor in bits of shrapnel..
1/2 hr and about 5 tools to take it apart…
3 weeks and a couple hundred to go back together…
Have fun! Don’t ride it
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These threads are the absolute best learning devices for the Moto Guzzi newbies like myself.
Mucho thanks to all who contributed.
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Thanks all for the advice. I will not ride the bike -- it sounds like a definite safety concern. My local "former Guzzi mechanic", a guy named Louis Bringer, seems to have disconnected his phone, so I will probably be attempting this repair myself. The parts don't look hard to get or *that* expensive. Since my T3's was built in '75, apparently it may have the earlier Ambo-style u-joint and carrier bearing (according to MG Cycle) so I will take it apart and see if I can tell the difference. I assume that my "clutch slipping" problem was actually related to the driveshaft bits eating themselves. I'll post pics when I get it apart.
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Thanks all for the advice. I will not ride the bike -- it sounds like a definite safety concern. My local "former Guzzi mechanic", a guy named Louis Bringer, seems to have disconnected his phone, so I will probably be attempting this repair myself. The parts don't look hard to get or *that* expensive. Since my T3's was built in '75, apparently it may have the earlier Ambo-style u-joint and carrier bearing (according to MG Cycle) so I will take it apart and see if I can tell the difference. I assume that my "clutch slipping" problem was actually related to the driveshaft bits eating themselves. I'll post pics when I get it apart.
No, a clutch slipping problem is normally the clutch slipping. :smiley: This would be a *really* good time to get in there and fix stuff. I've said many times that if you *look* for problems on an old machine you will find them.
Destroyed swingarm. It was exciting.
No doubt had your undivided attention for a bit.. :smiley:
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850T models have the earlier u-joint. 850-t3 with disc brake in rear use latter u-joints.
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850T models have the earlier u-joint. 850-t3 with disc brake in rear use latter u-joints.
MG Cycle claims on its website that some early-build T3s (manufactured in 1975) came with the earlier carrier bearing an u-joint. I don't know if that's true or not.
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I am not saying this has anything to do with the mineral oil flush, maybe its part of whatever was making my clutch slip?
Any thoughts?
I'm only jumping in to possibly save someone mechanical grief in the future,
The mineral flush just before the apparent demise of your U-Joint, may possibly be related.
I researched extensively when I did the mineral flush, to cure the slipping clutch on my CalVin.
One of the warnings I read, was that when you have the mineral spirits in the bell housing with the bike supported up on the center stand/stands and are putting the bike into gear and fanning the clutch to clean the plates; you have to be very careful that the swing arm is supported in some fashion or at least verified that it's not hanging down in a sharp, unusual downward angle.
If you do that part of the flush, with the tranny engaged & driveshaft spinning and the swing arm is hanging down in a severe angle, the U Joint is turning at an angle it's not used to, with potential for failure.
Great advice by others already on the U Joint job, the only caution I'd add is, be gentle with the fine machine threads in the swing arm at the pivot point, be very careful that you don't cross thread on reassembly; make sure you treat them with your favorite anti corrosion recipe. Iirc I used something by Loc-Tite
fwiw good luck
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That's weird though...the shock absorbers don't need to be taken off to do a clutch flush so the swinging arm will still be held up.Can't conceive why you would do that to do this procedure but open to enlightement :grin:.
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These threads are the absolute best learning devices for the Moto Guzzi newbies like myself.
Mucho thanks to all who contributed.
I would not have made it through Guzzidiag without Gonzo, Paul Brooking and (of course Beetle’s tutelage).
Maybe I would have gotten there, but would not have had the guts to try… :bow: :thumb:
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That's weird though...the shock absorbers don't need to be taken off to do a clutch flush so the swinging arm will still be held up.Can't conceive why you would do that to do this procedure but open to enlightement :grin:.
You don't take the shocks off to do the flush, or at least I didn't.
In theory, I suppose the shocks may hold the swing arm at a good angle, but I think by design they're intended to move down enough to compensate for holes or dips in the road,idk.
What I do know, is that every bike/shock/swing arm/U Joint is going to be it's own unique package, due to design/wear/corrosion/dirt/debris etc.
I didn't do anything special when I did my flush and I was lucky with no mechanical carnage, others apparently haven't been so lucky.
Something to bear in mind, nothing more.
fwiw ymmv
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Maybe I did the flush wrong, but I didn't have the bike in gear. I had it up on the center stand, in neutral, and started the bike, revved it in neutral, and flashed the clutch open and closed a bunch of times. So the u-joint wasn't spinning.
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I really can't see how the flush would have anything to do with a UJ wear issue and this now seems to be what you have. I'd Definitely have a looksee before riding again.
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I would not have made it through Guzzidiag without Gonzo, Paul Brooking and (of course Beetle’s tutelage).
Maybe I would have gotten there, but would not have had the guts to try… :bow: :thumb:
Yeah it is cool to be able to read the threads and vicariously live some of the Moto Guzzi experiences without actually going thru them. Very easy to see why people have a love/hate relationship for the bikes.
The honest relating of the less than optimal Moto Guzzi quirks, can definitely lead one to think "Yeah, that's no big deal! I wanted a bike with charm and personality and this is just part of the package!"
Let's face it, whenever anything goes to Hell in a hand basket, at least you are going to get some good stories and common experiences out of the situation."
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Maybe I did the flush wrong, but I didn't have the bike in gear. I had it up on the center stand, in neutral, and started the bike, revved it in neutral, and flashed the clutch open and closed a bunch of times. So the u-joint wasn't spinning.
You ought to be fine. Certainly made a fine mess, didn't it? :smiley:
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I did my clutch cleaning through the inspection window with brake cleaner. In neutral. Bunch of gunk came out the bottom. Feels like it’s holding strong. I’m not looking forward to changing that carrier bearing if/when I need to
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I’m not looking forward to changing that carrier bearing if/when I need to
I recently bought this tool to press the u-joint into the carrier bearing. That along with a HarborFreight press made it an easy job.
(https://i.ibb.co/SNjjh3r/90-F6-DD0-B-065-B-4253-9469-E4-ACB073896-E.jpg)
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You ought to be fine. Certainly made a fine mess, didn't it? :smiley:
Yeah it made a big mess! The mineral spirits got flown out of the inspection hole all over the driveway. My wife was like, "what's all that milk all over driveway?"
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I recently bought this tool to press the u-joint into the That along with a HarborFreight press made it an easy job.
(https://i.ibb.co/SNjjh3r/90-F6-DD0-B-065-B-4253-9469-E4-ACB073896-E.jpg)
Where did you buy the tool?
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Unfortunately it was the last one MG Cycle had and it only works with the older u-joints. Won't work on the newer u-joints as they are slightly larger. If you go to This Old Tractor there is a thread on making a similar tool out of a PVC pipe.
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Yeah it made a big mess! The mineral spirits got flown out of the inspection hole all over the driveway. My wife was like, "what's all that milk all over driveway?"
To make an even finer mess.. :smiley: plug the slot that drains the bell housing. That way you can get a fair amount more mineral spirits in there before starting it and actuating the clutch a few times.
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Unfortunately it was the last one MG Cycle had and it only works with the older u-joints. Won't work on the newer u-joints as they are slightly larger. If you go to This Old Tractor there is a thread on making a similar tool out of a PVC pipe.
I've got a stainless sleeve which does exactly this...slightly too large to I put some cardboard in to take up the slack.Worked a treat some 60,000 miles ago !
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I got the rear end off today. You guys weren't kidding, it's pretty easy! There was some first-time idiocy. I forgot to loosen the hose clamp on the rubber boot, and couldn't figure out why the swing arm wouldn't pull free. And I forgot to remove the forward bolt for the left side foot pegs, which interfere with with the removal process as well.
I was kind of shocked to see that the drive shaft isn't attached to anything. I had no idea it was just a slip-fit into teeth on the u-joint.
I don't see any obvious problems, but I went ahead and ordered a new u-joint and carrier bearing, and will replace the swing arm bearings as well. The old u-joint is very loose on one side, but it doesn't seem to have obviously excessive play. I have no idea what I'm doing of course, but there was definitely no obvious damage, metal flakes, etc.
The main hiccup is the carrier bearing. I got the blind bearing/slide hammer kit from Harbour Freight, and the bearing still doesn't move despite lots of hammering. Yes, I took off the circlip. I think I'll just take it to the local machine shop and also have them put the new bearing in.
Two questions:
- Do you all recommend replacing anything else while I am in this far? I am not planning on crabbing the frame to do the clutch, but I was wondering about whether it's recommended to preventively change the two accessible transmission seals (one in the final drive, one on the output shaft)? I found a bit of oil in the output shaft area. Is that normal? The rear drive seems to be fine, no obvious leaking.
- I read about putting moly "grease" on the shaft splines before reassembly. Should I grease the new u-joint to? How is it lubricated?
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I usually drive the carrier bearing out from the rear of the swing arm, long 1/2 drive extension and a socket that fits throught the swing arm. I have been battering tools like this for a very long time I'm not proud of the misuse but like to get the job done. YMMV
Brian
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Sometimes the bearing can be a real Bastard to get out, I have resorted a number of times to welding a half inch drive socket to the inner race, put a 12-inch extension in to beat on. DonG
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“the old ujoint was loose on one side ..”
Should be zero play..probably was getting ready to begin to about to be a grenade :grin:
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“the old ujoint was loose on one side ..”
Should be zero play..probably was getting ready to begin to about to be a grenade :grin:
This. And you might rethink not looking at the clutch if it's been slipping. It's really no big deal.
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This. And you might rethink not looking at the clutch if it's been slipping. It's really no big deal.
Chuck's right (as usual) :wink:. If you're this far in, definitely go the rest of the way and take care of the clutch. You'll kick yourself if you need to go through everything again.
Also, if you do decide to pull the gearbox, here's a guide with a section about addressing things inside the bellhousing. It's from the loopframe section, but I think that much of the info will still be relevant.
https://www.thisoldtractor.com/moto_guzzi_loopframe_engine_out__check_these_things.html
Cheers,
Shaun
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heat gun does wonders for removing the carrier bearing
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The main hiccup is the carrier bearing. I got the blind bearing/slide hammer kit from Harbour Freight, and the bearing still doesn't move despite lots of hammering. Yes, I took off the circlip. I think I'll just take it to the local machine shop and also have them put the new bearing in.
Two questions:
- Do you all recommend replacing anything else while I am in this far? I am not planning on crabbing the frame to do the clutch, but I was wondering about whether it's recommended to preventively change the two accessible transmission seals (one in the final drive, one on the output shaft)? I found a bit of oil in the output shaft area. Is that normal? The rear drive seems to be fine, no obvious leaking.
- I read about putting moly "grease" on the shaft splines before reassembly. Should I grease the new u-joint to? How is it lubricated?
I put the largest collet from my blind bearing puller in the bearing, stick a 1" diameter rod in from the rear drive end, and then use the hydraulic press to remove the bearing. I machined a 6061 slug into a tool for installing the new one without damage.
About the bearing... use the best quality bearing you can find - SKF, FAG, Nachi, Koyo, etc. I do not recommend the (Russian, Chinese?) bearing sold by some parts retailers. Doesn't hurt to use a C3 clearance bearing either.
I grease all the splines with Wurth SIG 3000. The u-joint is "permanently sealed" and is already greased.
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Chuck's right (as usual) :wink:. If you're this far in, definitely go the rest of the way and take care of the clutch. You'll kick yourself if you need to go through everything again.
Also, if you do decide to pull the gearbox, here's a guide with a section about addressing things inside the bellhousing. It's from the loopframe section, but I think that much of the info will still be relevant.
https://www.thisoldtractor.com/moto_guzzi_loopframe_engine_out__check_these_things.html
Cheers,
Shaun
OK you guys convinced me. I ordered the RAM clutch from MG Cycle and some other bits, and spent the afternoon tearing the bike further down. I am going to use this as an opportunity to reinstall the floorboards that I removed 15 years ago too, since it's pretty easy now to yank the lower frame rails. The bike disassembles pretty easily. Hopefully it will be just as easy putting it back together (+:.
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I had asked MG Cycle about the RAM clutch a few years back. They said it was significantly lighter then the stock unit on my T3. It would be suitable if driven in a "sporty" manner but I would be giving up my nice solid idle at published RPM. I really like the stock performance so I rebuilt the original clutch.
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When I changed the clutch in mine the new clutch plates had bigger internal teeth so I had to change the gearbox clutch hub to suit.
If the clutch is slipping and you have it all apart, I would change the rear main seal. If there's oil causing slippage then its either from the gearbox input or rear main. With the box out take the clutch hub off and change the seal and by memory there's an o ring on the shaft behind the hub. Very easy to do, just get the socket for the slotted lock nut to avoid butchering it with a chisel. I would also change the gasket on the engine breather tube flange.
Heres a useful gearbox manual for reference from the This Old Tractor site if needed.
https://www.thisoldtractor.com/guzzitech.dk/pdf/gearbox-rebuilding-john-noble_print.pdf
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I recently bought this tool to press the u-joint into the carrier bearing. That along with a HarborFreight press made it an easy job.
(https://i.ibb.co/SNjjh3r/90-F6-DD0-B-065-B-4253-9469-E4-ACB073896-E.jpg)
I made a similar tool out of PVC pipe. It worked fine after I froze the U-joint and gently heated the bearing with a heat gun on the lowest setting.
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Just to verify, I'm a bit paranoid about this, to take out the bell housing, I *don't* take off the "cover" but rather undo the bolts closest to the engine case, and then the whole bell housing will come off in one bit, and stay together? I don't want to have to get into the transmission if I don't have to. I read the long tutorial on ThisOldTractor about rebuilding the transmission, which I don't think I need to do or don't want to do,, but I'm still not sure--if I pull the bell housing without removing the "cover" can I just remove, set to the side, and then re-fit once the new clutch is in?
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Just to verify, I'm a bit paranoid about this, to take out the bell housing, I *don't* take off the "cover" but rather undo the bolts closest to the engine case, and then the whole bell housing will come off in one bit, and stay together? I don't want to have to get into the transmission if I don't have to. I read the long tutorial on ThisOldTractor about rebuilding the transmission, which I don't think I need to do or don't want to do,, but I'm still not sure--if I pull the bell housing without removing the "cover" can I just remove, set to the side, and then re-fit once the new clutch is in?
(https://i.ibb.co/WtBbfcN/20190807-213637.jpg) (https://ibb.co/WtBbfcN)
No reason to he afraid of the transmission. If you pull the input spline nut and coupling the whole transmission internals can be dropped on the bench on its back cover completely assembled. Then its a matter of photo and disassemble in steps you are comfortable with and replace anything that qualifies as worn or damaged. Put it all back together on the back cover and drop the housing on (add the detent).
But undoing the forward set of fasteners will remove the whole transmission without any transmission changes, exposures, disturbances etc. It is located by two dowels and might stick a bit.
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To remove the gearbox, just remove the bellhousing mounting nuts right next to the engine. Once you have the gearbox on the bench, you can work on the hub inside the bellhousing. No need to completely disassemble the gearbox.
Cheers,
Shaun
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I wouldn’t dig into a good operating gearbox. Rear main seal, clutch, (make sure the clutch plates you buy match your clutch hub, or buy a complete kit from MG Cycle), throw out bearing and pushrod seals are all great candidates for replacement while you are in there. Don’t forget new flywheel and pressure plate bolts.
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If you have the flywheel off which you may not, but if you do, clean the rear camshaft plug and put a good sealant over it. Clean it like you are going to paint it and use your favorite two part sealant. They can start to seep as they age.