Lost in France

[oilman321]

Hi folks any help appreciated here. In France couple of weeks ago for the 100TH anniversary of the start of the battle of the Somme. An experience so emotional my 1993 Pan st1100 had a breakdown.
Changing gears heard a clunk then no drive. Engine sounds fine and can go up and down through the gears fine but bike will not move. Bike remains in France awaiting repatriation from the breakdown service provider I took insurance out with. Phew !
Question. Breakdown service say my clutch is U/S. Would I still be able to move up and down gears if clutch was U/S. I was tending to think more likely to be drive shaft issue as I had heard the clunk noise once previously about 10 mins before the second one but put it down to something hitting bike. When I have bike back is there anyway of checking Clutch or Drive shaft to try and eliminate either and save my self some work.
Thanks for any advice
Harry

 

[SMSW]

I have never tried this on an ST, but on my old Triumph (more years ago than I want to admit), the clutch cable broke on my way home from work. I got off the bike, pushed it a bit at idle, hopped aboard and hit the shift lever - i was rolling in 1st. Accelerated a bit, rolled the throttle off somewhat and shifted into 2nd. And so on. The secret is to get the revs down and no load on the engine. No clutch cable so I never disengaged the clutch. At stoplights I pulled over into the right lane, waited for traffic to clear, and repeated this. Got home ok. There should be no reason why the ST will not work like this, though you might need a gorilla to help push the bike up to a couple of mph (kph) before you shift into first.

However, if the clutch is engaged and you put the bike in gear (engine off) you should not be able to roll the bike forward or back more than the slack in the drive train. And given the number of springs on the clutch plates (is it 6?) I cannot imagine more than 1 or 2 failing at any give point. Never heard of a clutch breaking disengaged though anything is possible. if you can squeeze the clutch lever and feel the usual resistance against the clutch springs, I would expect the clutch is fine - try shifting thru the gears at idle w/ the clutch pulled in.

To directly answer your q - sure, no reason why you cannot shift up and down with the clutch engaged. I've done this on my ST during winter servicing. You might need to put the bike on the center stand and roll the back tire a bit forward and back to get the gears to mesh (assumes a good drive train and engine is off) but you should be able to engage all the gears. Why not put it on the center stand and try this with the engine running? Keep the revs low and the rear tire should spin.

None of these tests might be possible if your bike is in France and you are not.

I agree w/ you that it is a driveshaft issue.

 

[oilman321]

Thanks. I had the engine running at idle in France and went through the gears at the side of the road with the bike on centre stand and the back wheel did not move. No funny noises coming from Engine and clutch felt fine. Is it possible to see the drive end of the drive shaft in situ as my feeling is it may be a drive shaft universal joint failure hence the three clunks which may have been it breaking ? Just got word I will have it back on the 21st July. Looks like my new bike lift came not a minute too soon !

 

[Mcreviver]

BREXIT=Broken Rear End eXtends International Trip.

 

[ST1100Y]

I was tending to think more likely to be drive shaft issue...

Either this or, more likely, drive-splines (thus also ring-gear) totally worn down... (conscience-question: when was the last time you'd inspected/lubed the splines?)

 

[oilman321]

You obviously have far too much time on your hands McReviver. Quite good though.

 

[oilman321]

All lubes changed about 3K Miles ago. If it is total wear down would there not have been some indication of this prior to total loss of drive. Such as clunking between gears, or when initially pulling away as the "Slack in the splies/gear wheel are taken up. Bike was running perfect. Then a clunk followed by another clunk 10 mins later and then no drive.

 

[sirepair]

Pull the rear wheel and final drive off; should only take about 30 minutes max. You can then inspect splines and drive shaft.

 

[Mcreviver]

You obviously have far too much time on your hands McReviver. Quite good though.

Uh, yep, retired for about a year now. Should be out riding but it's a bit warm and I have an air conditioner project in the works.
Hoping you don't find too much complicated damage.

 

[oilman321]

30 mins to remove drive shaft. Thought the swing arm has to come off to remove drive shaft ?

 

[John OoSTerhuis]

Either this or, more likely, drive-splines (thus also ring-gear) totally worn down... (conscience-question: when was the last time you'd inspected/lubed the splines?)

+1 Sure sounds like final drive splines failed/worn-out. IMHO

John

 

[sirepair]

30 mins to remove drive shaft. Thought the swing arm has to come off to remove drive shaft ?

Just to check if it's broke.

 

[ST1100Y]

...would there not have been some indication of this prior to total loss of drive. Such as clunking between gears, or when initially pulling away as the "Slack in the splies/gear wheel are taken up. Bike was running perfect. Then a clunk followed by another clunk 10 mins later and then no drive.

Yes, with those sudden symptoms it could indeed be a blown U-joint... but normally such wear-down "announces" itself with significant vibrations from/in the drive-train; anything of that kind prior the failure?

There also two safety/slip-couplings in the drive train:
- one inside the drive-shaft (hidden inside the black cup/casing)
- a larger one in the main-shaft of gear-box
Both basically a large spring, forcing a ring with two fingers on/into another ring with two slots, intended to "slip" upon attempted wheelies, popping the clutch or something inside the drive-train seizing.
Wear of those couplings shows by a loud/significant "knack" upon take-off (feels like someone bangs a hammer at the undercarriage), haven't seen one failing yet though, but who knows what Gremlins can come up with...

Anyway, rear wheel out, check splines and ring-gear, remove final drive from swing-arm and check drive-shaft...

 

[dwalby]

30 mins to remove drive shaft. Thought the swing arm has to come off to remove drive shaft ?

He said 30 mins to pull the rear wheel and final drive unit, the swingarm stays on for that. Pull the rear wheel and look at the splines. If they're worn bad enough to produce the symptoms you're seeing, it will be immediately obvious. If they're good, then run the bike and see if the splines inside the final drive are rotating. If they aren't turning, then something failed in the drive shaft, so pull the final drive unit and see if the drive shaft is turning and if its splines look good.

I'm not sure if you can run the bike to check if the drive shaft is turning with the final drive removed though, removing it might allow the shaft to flop around, so I'd wait for a reply from someone who has done that work before. I'd try turning it by hand first to see if there's any mechanical resistance or not. If it spins freely with no resistance you may have a failed U-joint, but I've never had that failure so I can't offer any help on exactly what to look for.

 

[caddyman]

I had the same thing on an old cx 500, both the drive shaft and the wheel spines had stripped, a pain but easier to sort than a broken gear box!!

 

[Ashley]

I'd start by putting on center stand, in gear, not running and try to spin wheel by hand and try to tell where the ugly noise comes from if any.

 

[John OoSTerhuis]

I'd start by putting on center stand, in gear, not running and try to spin wheel by hand and try to tell where the ugly noise comes from if any.

Excellent advice/first step!

 

[oilman321]

Thanks for your advice guys. Now have bike back and upon putting it on the lift and on the center stand putting it in gear it was blatantly obvious where the problem lay. Sounded like a bag of spanners inside the final drive. Have pulled wheel and drive flange splines are almost gone but only on the ends bout 5mm. Drive hub splines also look worn (I take it these are supposed to look squared when in good condition. mine are like wedges) also cush rubber aluminium inserts, the holes are oval with a lip of metal at the leading edge.
Question I know there should be an O Ring on the outer of the drive flange. There is also a large washer/shim on the wheel side of the drive flange. Should there be another O ring here. I have read that they have a tendency to powder and disappear. Only asking as my damage looks like the drive flange and the drive hub splines have either moved apart or have not been fitted correctly as its only the end 5mm of the splines that have damage. I put the drive flange back into the splines on the drive hub fully inserted and no way could I get then to slip. I will try and post pics later. Anyway sourced replacement used parts in good condition which should be here in a week. So I'll keep you updated. I noticed when searching for parts that the drive flange (The part that fits into the wheel) has been discontinued) Hence the mad prices for second hand in the UK I suppose.

 

[Ashley]

Photos please...

 

[oilman321]

Will get some on later today. At work at moment.