Classic British SparesKlempf British PartsBaxter CycleBritBike Sponsor SteadfastCyclesSRM EngineeringLucas Classic MotorcycleHepolite PistonsIndustrial tec supply

Upgrade your membership to: Premium Membership | Gold Membership | Life Membership | Vendor Membership | Site Sponsor Membership
Welcome to BritBike Forum!
Britbike forum logo
Member Spotlight
kommando
kommando
Scotland
Posts: 11,054
Joined: December 2004
ShoutChat
Comment Guidelines: Do post respectful and insightful comments. Don't flame, hate, spam.
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Previous Thread
Next Thread
Print Thread
Page 1 of 2 1 2
Joined: Feb 2017
Posts: 140
Likes: 2
Britbike forum member
OP Offline
Britbike forum member
Joined: Feb 2017
Posts: 140
Likes: 2
Iv'e found the part No for my 74 T140v clutch sprocket & housing and is given as 57-4640 however the one that iv'e taken off has fibre bonded at the back this would explain why i pulled 7 plain plates out of the basket, the roller bearing face in the housing is completely shot as is the face on the center hub,was this housing on later models only and does anyone know the part No please, later parts lists are showing the same No 57-4640 confused

Thanks Dave


Always remember there are 3 kinds of people in this world,those that can count & those that can't.
T140V 1974
GT750 1974
GT550 1974
TL1000 97s
Support Your #1 BritBike Forum!

Check out British motorcycles for sale: British Motorcycles on e-Bay UK, British motorcycles on e-Bay North America
Joined: Mar 2006
Posts: 4,793
Likes: 41
Britbike forum member
Online Content
Britbike forum member
Joined: Mar 2006
Posts: 4,793
Likes: 41
Originally Posted by Dave Lid
Iv'e found the part No for my 74 T140v clutch sprocket & housing and is given as 57-4640 however the one that iv'e taken off has fibre bonded at the back this would explain why i pulled 7 plain plates out of the basket,

does anyone know the part No please, later parts lists are showing the same No 57-4640 confused

I believe it is 57-7065 but I'm not sure it is still available.

The friction plates are also thinner than standard, apparently.
http://www.britbike.com/forums/ubbthreads.php/topics/130769/re-clutch-plate-thickness#Post130769

Joined: Nov 2012
Posts: 1,913
Likes: 45
K
Britbike forum member
Offline
Britbike forum member
K
Joined: Nov 2012
Posts: 1,913
Likes: 45
The friction material bonded to the basket was an attempt by Triumph to deal with a perceived clutch defiency (slippage), though I didn’t think it was used until much later than 1974 (I thought it was the 80's).

It effectively made it a 7-plate clutch with standard plates (eliminating the wasted thickness of the first friction plate bar one friction thickness), so allowing one more plain plate in the pack = 2 more friction surfaces.

I can’t imagine this is original to your bike, and as LAB says, will be hard to replace.
Just get the ordinary clutch drum, and maybe one of the 7 plate options if concerned about potential slip.

Joined: Mar 2006
Posts: 4,793
Likes: 41
Britbike forum member
Online Content
Britbike forum member
Joined: Mar 2006
Posts: 4,793
Likes: 41
Originally Posted by koan58
The friction material bonded to the basket was an attempt by Triumph to deal with a perceived clutch defiency (slippage), though I didn’t think it was used until much later than 1974 (I thought it was the 80's).

1981, I believe.

1 member likes this: koan58
Joined: Jan 2017
Posts: 1,467
Likes: 51
T
Britbike forum member
Offline
Britbike forum member
T
Joined: Jan 2017
Posts: 1,467
Likes: 51
Hi, Yes ‘81 Triumph introduced its version of 7 plate clutch.
The plates were thinner than normal overall, but not nearly as thin as what we commonly call 7 plate.

Got this clutch version the 81 & later shop Manual stated plate minimum thickness.

More importantly this clutch reverted to 650 springs to reduce lever effort over 750 springs, yet not slip.

These pop up on eBay on very rare occasion. Seems clutch plates are even less common.

My recommendation since bearing & surfaces are bad is get all of the normal clutch parts for ‘74 T140 which are easy to come by. Then get Aerco 7 plate +1 kit & 6 more plain steel plates. Get 650 springs. Or verify you have good 650 springs.

Reuse steel pressure plate, rod etc.

This is a proven combination & will give excellent operation.
I can assure you of that.
Don


1973 Tiger 750
Joined: Feb 2017
Posts: 140
Likes: 2
Britbike forum member
OP Offline
Britbike forum member
Joined: Feb 2017
Posts: 140
Likes: 2
Thank you guys for the info and advice so having taken the steps have ordered the 74 parts listed sprocket & housing and also the center hub :)best new to be sure rather than find you have the same problem with a used part.Having measured the pads in the sprocket housing i have 00.170" i'm thinking could i slip a friction plate in and retain the 7plates that i had having the later housing.My main concern is why the bearings where starved of lube believe me the are a mess and the thrust washer I/D has run completely oval, with 150mm in the primary casing do you guys think this is enough and are the bearings & faces lubed through the 4 holes in the center hub.Just want to be sure it's not going to happen again frown

Thanks Dave


Always remember there are 3 kinds of people in this world,those that can count & those that can't.
T140V 1974
GT750 1974
GT550 1974
TL1000 97s
Joined: Nov 2012
Posts: 1,913
Likes: 45
K
Britbike forum member
Offline
Britbike forum member
K
Joined: Nov 2012
Posts: 1,913
Likes: 45
The roller bearing assembly in the clutch basket does very little work (its only doing anything when the clutch lever is pulled).

The most likely reason it is shot is through rusting damage when laid up for a significant length of time. The system breathing through the chaincase can expose the primary components to water vapour and so encourage corrosion.

The roller assembly and thrust washer would usually be assembled with grease (just makes it easier to hold it in place). Thereafter the oil splash in the chaincase will provide adequate lubrication.

The holes in the flange of the centre are usually quite sharp edged, and tend to shave the inner of the thrust washer, allowing it to become progressively more eccentric, resulting in a “wear spiral”. I blend the edges of the holes where the step is too avoid the “lathing” action. The thrust washer wears fast enough without any of this assistance.

SPECULATION
1) I don’t know whether the thrust washer can wear enough to be able to slip off its narrow shoulder on the hub. If it could, this could cause all manner of havoc.

2) With the basket with friction pads bonded to it, I can conceive of a situation whereby, when the thrust washer is worn thin, and those friction pads have also worn thin, the first plain plate at the back of the basket could fall off the cush hub and jam between hub and basket. Again, all manner of havoc.

Joined: Feb 2017
Posts: 140
Likes: 2
Britbike forum member
OP Offline
Britbike forum member
Joined: Feb 2017
Posts: 140
Likes: 2
Thanks Koan58 that does make a lot of sense to me the Bonnie having been laid up for about 11yrs prior to me having the bike,i did have the primary casing off to check the plates because the clutch would not free but didn't get in to check the bearings suppose lesson learnt ouch !!!! with the wallet

Thanks Dave


Always remember there are 3 kinds of people in this world,those that can count & those that can't.
T140V 1974
GT750 1974
GT550 1974
TL1000 97s
Joined: Jan 2017
Posts: 1,467
Likes: 51
T
Britbike forum member
Offline
Britbike forum member
T
Joined: Jan 2017
Posts: 1,467
Likes: 51
Hi Dave, I've only seen one case of such bad rust. I still have the parts. '71 Bonnie.

Regarding the thrust washer yes it will wear inner diameter such it falls off the shelf. It will be basically a hoop. Finally is seems to catch & tear, then deform & fall apart into a tangle into bottom of primary. Heaven help you if it fell into chain. I consider the thrust washer a fast wearing part.

Koan is 100% correct. A little over a year ago I got LF Harris small hub. I looked at the 4 holes. Didn't look all that bad. I decided to not chamfer holes. Big mistake. Wore a good 1/16" off ID of washer in 100 miles. Left a pile of metal chips on floor of primary case. Not so good. Don't repeat my mistake.

This is very important. The original '74 Triumph basket had very square corner at back for first plate clearance.

The Harris & Taiwan made have a chamfer in the back corner. So far 100% of time for me if you fit 7 plate the first friction won't set perfectly flat. The steel edge of plate catches on the chamfer. The cure is grind or file a chamfer on back edge of the steel part of friction plate. Doesn't need much. Just enough to set perfectly flat & have just a slight amount of wiggle room.

Also trial fit all the new plates to new parts & be sure they slide freely. Touch up high spots as needed with a file. Sadly new parts are not fitted so good as originals. Just a fact of life.
Don


1973 Tiger 750
Joined: Jan 2014
Posts: 3,323
Likes: 16
R
Britbike forum member
Offline
Britbike forum member
R
Joined: Jan 2014
Posts: 3,323
Likes: 16
Hi TR7RVMan;

May you explain again what you say about the small hub and the 4 holes problem? I tried to imagine it but may be I am thinking in other part?
I do not remember now when I put the Hyde plates (that are smaller than the Aerco, so in theory, better. I bought them in USA not in UK) about that problem but may be I would need to open the primary to check?

Thanks

Joined: Feb 2017
Posts: 140
Likes: 2
Britbike forum member
OP Offline
Britbike forum member
Joined: Feb 2017
Posts: 140
Likes: 2
Having gathered all new parts now to re-assemble clutch i'm having a right mare fitting the new cush rubbers any tips guy's seems impossible to do at the moment facepalm

Thanks Dave


Always remember there are 3 kinds of people in this world,those that can count & those that can't.
T140V 1974
GT750 1974
GT550 1974
TL1000 97s
Joined: Oct 2019
Posts: 39
Likes: 2
N
Noe Offline
Britbike forum member
Offline
Britbike forum member
N
Joined: Oct 2019
Posts: 39
Likes: 2
http://imgur.com/gallery/mIclwXg


I made this from scraps.

Good luck

1 member likes this: Dave Lid
Joined: Nov 2012
Posts: 1,913
Likes: 45
K
Britbike forum member
Offline
Britbike forum member
K
Joined: Nov 2012
Posts: 1,913
Likes: 45
You definitely need Noe’s tool or something that will do the same job, for example a peg spanner of appropriate size.
These allow you to put pressure on the big rubbers, to make room to slip the smaller ones in.

Of course you also need a way to hold the spider centre against the force of the above tool.

Easiest done using a vice with an old centre (or new one if careful with the clamping) and the above tool.

On the bike you can do this by putting the bike in top gear, tap the centre onto the taper (with key) and put the shock absorber on the centre and moderately clamp with washer/nut (leave the basket off at this time). Use the rear brake to hold the spider against the force of the above tool.

Either way, once you’ve compressed the big rubbers a little, the others will go in easily. Give them a slight smear of oil or grease first.

Joined: Feb 2017
Posts: 140
Likes: 2
Britbike forum member
OP Offline
Britbike forum member
Joined: Feb 2017
Posts: 140
Likes: 2
Thanks for the heads up so i need a driven plain plate to make up a tool will this also do as holding tool whilst torquing up the clutch center nut or do i need a bonded plate for that

Thanks Dave


Always remember there are 3 kinds of people in this world,those that can count & those that can't.
T140V 1974
GT750 1974
GT550 1974
TL1000 97s
Joined: Nov 2012
Posts: 1,913
Likes: 45
K
Britbike forum member
Offline
Britbike forum member
K
Joined: Nov 2012
Posts: 1,913
Likes: 45
To be fully useful, Noe's tool needs a bonded plate fixed to it as well. It will then enable tightening of the engine sprocket as well. As it is, it will allow tightening of the clutch centre nut for sure.

Joined: Jan 2017
Posts: 1,467
Likes: 51
T
Britbike forum member
Offline
Britbike forum member
T
Joined: Jan 2017
Posts: 1,467
Likes: 51
Hi Dave, Here's a tutorial I did on RAT group. The holder tool in vise is critical. A key factor to success. A bar of metal from hardware store, ground or filed to fit spline. Hold very tight in vise. No vise? Get one is all I can say.

The long handle on the home made tool is very helpful. I often will use a pipe on handle of my tool for more leverage.

T140 type is a little harder due to the back plate is loose. Keep at it & you'll soon see it's not too hard. The shop Manual with tire levers is not possible in real life with T140 parts. Might be possible but certainly impractical.

Once holder tool is very tightly clamped in vise, you can put great force on turning to compress rubbers with tool in safety for both you & the hub parts. You will find you can put the small rubbers in without fighting it. I've done many, many rubbers jobs on T140 (& earlier 650 with counter sink screws). I don't have to fight them at all since I made the good tools.

Also make sure you have correct rubbers. You'll see the correct ones on my post. The 3 cyl motor rubbers are similar, but slightly larger. They can be forced it, but it's a fight! I installed some for a test of them. I actually had to grind some rubber off to fit them.

Be sure to peen the end of the 3 bolts over. These like to work loose if not well tightened & secured. I use blue loctite on the the threads also.

Any questions at all on procedure PM me. I have more photos & info.

I can email you photos of any of my tools. I use a similar tool to Noe's, but handle is only on one side so it is easier to hold hub when tightening main shaft. I took old friction & steel plates & loosely bolted them together to replicate the factory holding tool I find the 2 part system a bit easier to use. I torque the clutch nut first using the tool made with steel plate & handle. Then install the double plate tool into basket to hold hub/basket locked together. Then refit the steel plate with handle tool to torque the crank nut. Again personal preference.

PM me & I'll email the photos of the 4 small holes. Sorry if I have your email already. I have so many I can't keep track as I didn't nick name them all to the online screen name. I just started doing that.
Don


1973 Tiger 750
1 member likes this: Noe
Joined: Jan 2017
Posts: 1,467
Likes: 51
T
Britbike forum member
Offline
Britbike forum member
T
Joined: Jan 2017
Posts: 1,467
Likes: 51
Hi Dave, .005" wear on back plate is not horrible, but I've observed when you get that on back plate the spider arm side is worn also. Together this can add up. The radial clearance of the spider in the cover bores can wear also. When wear is too great it allows the hub to "wobble" which oddly can result in clutch slipping under heavy loads. As well as the expected drag clutch released.

I attempted to face my worn back plate. It's too hard to turn on lathe. Surface grinding would work good. The backside of spider arms are not that hard. They could be turned back to parallel. After all of that the hub face would need to be turned to compensate for the material removed to restore end play. I don't know what factory end play is on new one. I couldn't tell on the new hub due to rubber tension. My hunch is about .001-.0015".

At the same time I've observed the grooves for tangs get quite worn. I've filed them. This works good about once. The wider grooves seem to wear the tangs faster.

I finally gave up & bought a new LF Harris cush hub. If I had a access to grinding back plate flat I could have machined the other parts.
Don


1973 Tiger 750
Joined: Feb 2017
Posts: 140
Likes: 2
Britbike forum member
OP Offline
Britbike forum member
Joined: Feb 2017
Posts: 140
Likes: 2
Surface grinding the back plate it is then Don for now and check that the spider arms are parallel.The way things are going i may just as well have bought a complete brand new clutch facepalm

Thanks Dave


Always remember there are 3 kinds of people in this world,those that can count & those that can't.
T140V 1974
GT750 1974
GT550 1974
TL1000 97s
Joined: Nov 2012
Posts: 1,913
Likes: 45
K
Britbike forum member
Offline
Britbike forum member
K
Joined: Nov 2012
Posts: 1,913
Likes: 45
Hi Dave,
I can’t imagine bothering to grind the backplate when you can get a new one from TMS for £18.
Even a new spider is £34.56 (which you may not need).
The whole absorber is £117.60.

http://www.tms-motorcycles.co.uk/store/products/list.asp?cat_id=158&order_by=name

Just thoughts.

Joined: Feb 2017
Posts: 140
Likes: 2
Britbike forum member
OP Offline
Britbike forum member
Joined: Feb 2017
Posts: 140
Likes: 2
That's a handy parts supplier Koan thanks for that i can get the surface grinding done for the plate it's only a gnats knacker and the paddle appears to be ok so all in all after Thursday's lock down all i need is another pair of hands to assemble to the bike laughing laughing

Thanks Dave

Last edited by Dave Lid; 11/02/20 9:28 pm.

Always remember there are 3 kinds of people in this world,those that can count & those that can't.
T140V 1974
GT750 1974
GT550 1974
TL1000 97s
Joined: Feb 2017
Posts: 140
Likes: 2
Britbike forum member
OP Offline
Britbike forum member
Joined: Feb 2017
Posts: 140
Likes: 2
Having ground the back plate flat i'm not happy with the amount of the paddle spline is now showing on the outer side of the back plate frown so iv'e ordered a new back plate.Why does the paddle end up tight on the back plate and put 3 nasty grooves in it i wouldn't have thought there's much movement in the actual paddle arms once the rubbers are tightly compressed in confused

Thanks Dave


Always remember there are 3 kinds of people in this world,those that can count & those that can't.
T140V 1974
GT750 1974
GT550 1974
TL1000 97s
Joined: Nov 2012
Posts: 1,913
Likes: 45
K
Britbike forum member
Offline
Britbike forum member
K
Joined: Nov 2012
Posts: 1,913
Likes: 45
“Having ground the back plate flat i'm not happy with the amount of the paddle spline is now showing on the outer side of the back plate”

Any reduction of thickness by grinding flat will be reflected by a corresponding increased protrusion of the spider hub through the backplate.
By the same token, any removal of material from the back surfaces of the paddle arms (whether by wear or machining) will add to this protrusion.

“Why does the paddle end up tight on the back plate and put 3 nasty grooves in it”

The spider is the only fixed part of the shock assembly, it is clamped firmly to the centre hub by the nut. The rest of the assembly is free to move relative to the spider, that’s the whole point.
The backplate is pulled up tight against the paddles by the clutch springs, it is always this way with the unit clutch design.

The pre-unit clutch design doesn’t have this issue, but instead has different issues of its own.

Last edited by koan58; 11/04/20 7:01 pm. Reason: Unecessary repetition
1 member likes this: Lorenzo
Joined: Feb 2017
Posts: 140
Likes: 2
Britbike forum member
OP Offline
Britbike forum member
Joined: Feb 2017
Posts: 140
Likes: 2
Cheers Koan yes that makes sense if you keep reducing metal thickness of the plate you have to reduce the paddle too as a result you are ultimately weakening the whole unit or in effect making the whole cush rubber unit unstable.

Thanks Dave


Always remember there are 3 kinds of people in this world,those that can count & those that can't.
T140V 1974
GT750 1974
GT550 1974
TL1000 97s
Joined: Jan 2017
Posts: 1,467
Likes: 51
T
Britbike forum member
Offline
Britbike forum member
T
Joined: Jan 2017
Posts: 1,467
Likes: 51
Hi Dave Lid, I sent you the photos. Had some delays, sorry. My computer was saying invalid email address for some reason, but it got sent anyway. Let me know if you don't receive it. My experience is if back plate is worn bad, spider is too. I've had a fair amount of practice on these clutches now.
Don


1973 Tiger 750
Joined: Feb 2017
Posts: 140
Likes: 2
Britbike forum member
OP Offline
Britbike forum member
Joined: Feb 2017
Posts: 140
Likes: 2
This clutch re- furb seems to be fighting me all the way frown every part either needs to be worked on or replaced.Having fitted the new cush rubbers ready to bolt outer & inner cover plates bang two of the threads stripped in the outer plate mad are there any torque settings for these 5/16" bolts the book is stating 10 lbft.With all parts on the bench is it better to assemble rollers etc and knock the damper unit onto the spline then offer them to the taper and key on the bike,any thoughts welcome please.

Thanks Dave


Always remember there are 3 kinds of people in this world,those that can count & those that can't.
T140V 1974
GT750 1974
GT550 1974
TL1000 97s
Page 1 of 2 1 2

Moderated by  John Healy 

Link Copied to Clipboard
Job CycleBritish Cycle SupplyMorries PlaceKlempf British PartsPodtronicVintage MagazineBSA Unit SinglesBritBike SponsorBritish Tools & FastenersBritBike SponsorBritBike Sponsor






© 1996-2021 britbike.com
Powered by UBB.threads™ PHP Forum Software 7.7.5