sprag clutch replacement - Page 3

350TSS · 09-04-2020, 10:19 PM

If you are using the rattle gun best to get deep impact sockets - ordinary ones can split with the rattle gun

alan s4 · 10-04-2020, 07:45 AM

Thanks guys, just waiting for all the stuff to arrive now.

alan s4 · 16-04-2020, 06:21 PM

Christmas comes early! 1 week turnaround from MotoRapido, v impressive given some parts had to come from Italy. All in (just for the sprag parts) £224.00. The clutch itself was only £49.00, the driven gear was £100.00, the cup spring (a bevelled washer) was £19.00 so it all adds up. I also ordered a new Nut for the flywheel as advised.

Ended up buying an impact gun from Machine Mart (450nm mains electric) and a 30mm deep impact socket from Halfords, nut spun off in seconds.

All going swimmingly until.......

alan s4 · 16-04-2020, 06:26 PM

This is the sprag clutch still attached to the rotor/boss thing.

Haynes manual....."remove the starter clutch holder from the rear of the flywheel (done that bit), then separate the one-way clutch holder".

I can't work out how to remove the sprag from the housing. Any suggestions, do you just prize it out??

Luddite · 16-04-2020, 08:25 PM

Turn the flywheel over and use two, (or more), of the eight screws which held the alternator rotor to the flywheel to push the flange out (don't screw them all the way in of course - just locate the threads into the flange). You can encourage them with a soft mallet if you support the flywheel edges and tap them alternately.

This from the workshop manual:

"Insert two of the bolts (25) just removed from flywheel rotor-side in their holes in order to remove the flange (13) and the starter clutch (21).

The starter clutch is a slight interference fit on the flange. To remove it, use a suitable drift.

Edit I've also included the refitting instructions for completeness as they're quite helpful.

When refitting the flange (13) to the flywheel (16), position it with the tapered side facing the flywheel.

When refitting the flange to flywheel, insert a pin or a wrench inside the hole for the rotor flywheel locating dowel (14) in order to line up flywheel holes with flange. This operation proves useful since the hole cannot be aligned after having fitted the flange to the flywheel due to the interference fit of this part.
Position the locating dowel (14) with the circlip (15) on the flywheel.
Apply threadlocker to the screws (25) and fix the rotor (23), the flange (13) and the starter clutch (21) to the flywheel (16).

alan s4 · 17-04-2020, 05:52 AM

Fantastic Luddite, lots of detail, surprisingly none of this mentioned in the Haynes manual.

alan s4 · 26-04-2020, 02:33 PM

Home stretch now, all new parts fitted and clutch sprag seems to be operating properly. I had lots of play in the sprag itself as well as wear to the driven gear. Bike only covered 24k, so not sure whether this is typical or not?

Anyway, last thing to do is torque up the flywheel nut as well as the cup spring/washer (both new) the washer is bevelled, question is should the raised/dished part be facing in or out. Looked at youtube stuff and in the manual - not 100% sure........

slob · 26-04-2020, 02:53 PM

The larger side of the washer and the flat side of the nut face the flywheel

sent you a PM

alan s4 · 26-04-2020, 03:40 PM

Brilliant, got the PM, thanks for that. 10/10 for the drawing, concave and convex not my strong point.

slob · 26-04-2020, 06:25 PM

Quote:

Originally Posted by alan s4

Brilliant, got the PM, thanks for that. 10/10 for the drawing, concave and convex not my strong point.

it’s easy: caves are hollow ;-)

Tim88 · 26-04-2020, 07:03 PM

Funny about the left hand thread, is this normal?

Darkness · 26-04-2020, 07:24 PM

Quote:

Originally Posted by Tim88

Funny about the left hand thread, is this normal?

I wondered that too!

Probably draughtsman’s license.

slob · 26-04-2020, 07:59 PM

hahaha! caught sketching in a hurry

alan s4 · 29-04-2020, 07:31 AM

Finally completed. Remarkable transformation when the start button is pressed. My bike has always died after 2 or 3 rotations, after 7 years of ownership I though this was normal. I think the sprag was on its last legs 7 years ago and I've been changing everything apart from the bloody sprag in that time!

Total parts bill was £224.00. I reckon the job would take 2 hours from start to finish once you know what you're doing.

Couldn't have done it without input from the forum, so thanks again to all those who contributed with hints/diagrams and hand drawn pictures!

Darren69 · 29-04-2020, 08:42 AM

Sorry if I missed it but which starter/battery cables did you use? Exactstart?

16-04-2020, 08:25 PM	#35
Luddite Registered User Join Date: Aug 2011 Location: Southampton Bike: M1100evo Posts: 2,465	Turn the flywheel over and use two, (or more), of the eight screws which held the alternator rotor to the flywheel to push the flange out (don't screw them all the way in of course - just locate the threads into the flange). You can encourage them with a soft mallet if you support the flywheel edges and tap them alternately. This from the workshop manual: "Insert two of the bolts (25) just removed from flywheel rotor-side in their holes in order to remove the flange (13) and the starter clutch (21). The starter clutch is a slight interference fit on the flange. To remove it, use a suitable drift. Edit I've also included the refitting instructions for completeness as they're quite helpful. When refitting the flange (13) to the flywheel (16), position it with the tapered side facing the flywheel. When refitting the flange to flywheel, insert a pin or a wrench inside the hole for the rotor flywheel locating dowel (14) in order to line up flywheel holes with flange. This operation proves useful since the hole cannot be aligned after having fitted the flange to the flywheel due to the interference fit of this part. Position the locating dowel (14) with the circlip (15) on the flywheel. Apply threadlocker to the screws (25) and fix the rotor (23), the flange (13) and the starter clutch (21) to the flywheel (16). Last edited by Luddite; 16-04-2020 at 09:12 PM..

26-04-2020, 02:53 PM	#38
slob . Join Date: Jul 2003 Location: East London Bike: Multiple Monsters Posts: 9,707	The larger side of the washer and the flat side of the nut face the flywheel sent you a PM Last edited by slob; 26-04-2020 at 03:13 PM..

29-04-2020, 08:42 AM	#45
Darren69 Transmaniacon MOC Join Date: Sep 2013 Location: Sutton In Ashfield Bike: Multiple Monsters Posts: 6,022	Sorry if I missed it but which starter/battery cables did you use? Exactstart? __________________ Roast Beef Monster! Termignoni and Bucci - Italian for pipe and slippers! S4 Fogarty, S4R 07T, 748, Series 1 Mirage

09-04-2020, 10:19 PM	#31
350TSS Too much time on my hands member Join Date: Jan 2013 Location: Shipbourne Bike: M900 Posts: 1,419	If you are using the rattle gun best to get deep impact sockets - ordinary ones can split with the rattle gun

10-04-2020, 07:45 AM	#32
alan s4 Registered User Join Date: Sep 2013 Location: Glasgow Bike: S4 challenge Posts: 447	Thanks guys, just waiting for all the stuff to arrive now.

16-04-2020, 06:21 PM	#33
alan s4 Registered User Join Date: Sep 2013 Location: Glasgow Bike: S4 challenge Posts: 447	Christmas comes early! 1 week turnaround from MotoRapido, v impressive given some parts had to come from Italy. All in (just for the sprag parts) £224.00. The clutch itself was only £49.00, the driven gear was £100.00, the cup spring (a bevelled washer) was £19.00 so it all adds up. I also ordered a new Nut for the flywheel as advised. Ended up buying an impact gun from Machine Mart (450nm mains electric) and a 30mm deep impact socket from Halfords, nut spun off in seconds. All going swimmingly until.......

16-04-2020, 06:26 PM	#34
alan s4 Registered User Join Date: Sep 2013 Location: Glasgow Bike: S4 challenge Posts: 447	This is the sprag clutch still attached to the rotor/boss thing. Haynes manual....."remove the starter clutch holder from the rear of the flywheel (done that bit), then separate the one-way clutch holder". I can't work out how to remove the sprag from the housing. Any suggestions, do you just prize it out??

17-04-2020, 05:52 AM	#36
alan s4 Registered User Join Date: Sep 2013 Location: Glasgow Bike: S4 challenge Posts: 447	Fantastic Luddite, lots of detail, surprisingly none of this mentioned in the Haynes manual.

26-04-2020, 02:33 PM	#37
alan s4 Registered User Join Date: Sep 2013 Location: Glasgow Bike: S4 challenge Posts: 447	Home stretch now, all new parts fitted and clutch sprag seems to be operating properly. I had lots of play in the sprag itself as well as wear to the driven gear. Bike only covered 24k, so not sure whether this is typical or not? Anyway, last thing to do is torque up the flywheel nut as well as the cup spring/washer (both new) the washer is bevelled, question is should the raised/dished part be facing in or out. Looked at youtube stuff and in the manual - not 100% sure........

26-04-2020, 03:40 PM	#39
alan s4 Registered User Join Date: Sep 2013 Location: Glasgow Bike: S4 challenge Posts: 447	Brilliant, got the PM, thanks for that. 10/10 for the drawing, concave and convex not my strong point.

26-04-2020, 07:03 PM	#41
Tim88 Registered User Join Date: Mar 2016 Location: London Bike: M1100evo Posts: 98	Funny about the left hand thread, is this normal?

26-04-2020, 07:59 PM	#43
slob . Join Date: Jul 2003 Location: East London Bike: Multiple Monsters Posts: 9,707	hahaha! caught sketching in a hurry

29-04-2020, 07:31 AM	#44
alan s4 Registered User Join Date: Sep 2013 Location: Glasgow Bike: S4 challenge Posts: 447	Finally completed. Remarkable transformation when the start button is pressed. My bike has always died after 2 or 3 rotations, after 7 years of ownership I though this was normal. I think the sprag was on its last legs 7 years ago and I've been changing everything apart from the bloody sprag in that time! Total parts bill was £224.00. I reckon the job would take 2 hours from start to finish once you know what you're doing. Couldn't have done it without input from the forum, so thanks again to all those who contributed with hints/diagrams and hand drawn pictures!