BritBike Forum logo
BritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike Sponsor SteadfastCyclesBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorHepolite PistonsBritBike Sponsor
Upgrade to: Premium Membership | Gold Membership | Life Membership | Vendor Membership | Site Sponsor Membership
Member Spotlight
Don Leaming
Don Leaming
Ontario Canada
Posts: 1,007
Joined: January 2005
New BritBike book out!
ShoutChat Box
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
Random Gallery photo
Manuals on DVD (Shipping included)
Previous Thread
Next Thread
Print Thread
Rate Thread
Norton Crank End Play
#788144 10/25/19 5:43 pm
Joined: Jan 2014
Posts: 105
S
Samsmc1 Offline OP
Britbike forum member
OP Offline
Britbike forum member
S
Joined: Jan 2014
Posts: 105
I just realized that Norton doesn't suggest a crank end play for their engines.
Rarely do I get to actually take an engine apart (most come to me in pieces) until yesterday - there were no shims behind the main bearings.
I needed a cam thrust washer and an oil pump from a bottom end that has sustained major case damage in a crash.
I see a shim listed with A/R meaning as required in the parts books, but I can't find an end play specification anywhere.
Did I miss something here??
Thanks
Sam

Support Your #1 BritBike Forum!

Check out British motorcycles for sale: British Motorcycles on e-Bay UK, British motorcycles on e-Bay North America
Re: Norton Crank End Play
Samsmc1 #788150 10/25/19 6:44 pm
Joined: Jan 2014
Posts: 105
S
Samsmc1 Offline OP
Britbike forum member
OP Offline
Britbike forum member
S
Joined: Jan 2014
Posts: 105
Scratch this request - I googled the question and came up with .005 to .010.
Thanks

Re: Norton Crank End Play
Samsmc1 #788151 10/25/19 6:47 pm
Joined: Aug 2001
Posts: 1,394
Likes: 6
D
Crew Chief
Offline
Crew Chief
D
Joined: Aug 2001
Posts: 1,394
Likes: 6
Didn't miss much...
the lates shop manual shows .025" end play as acceptable. Some guys shoot for .005 (room temp) which to me is silly since if you ever start the engine in the winter the aluminum cases shrink and the clearance goes virtually to ZERO!
IPL show pix of shims behind mains in the case but the PN comes as small crank bearing inners.I always put the shims on the crank if I bother. I hate to pull the bearing out of the cases.

Please declare you engine series 20M3 20M3S 200000 300000 325000+
caution if you are working on a 200000 series, do not use OEM style bearing setup


dynodave
BSA 3 1961-1963
Ducati 3 1992-2002
Norton many 1951-1975
87 Serv-Equip 100HP MC brake dynamometer,
Re: Norton Crank End Play
Samsmc1 #788152 10/25/19 6:49 pm
Joined: Jan 2014
Posts: 105
S
Samsmc1 Offline OP
Britbike forum member
OP Offline
Britbike forum member
S
Joined: Jan 2014
Posts: 105
I have .022 right now with no shims - where did you get the .025 number from?
I really don't want to pull a main bearing if I can help it plus I always like more clearance then less.

Re: Norton Crank End Play
Samsmc1 #788153 10/25/19 6:51 pm
Joined: Jan 2014
Posts: 105
S
Samsmc1 Offline OP
Britbike forum member
OP Offline
Britbike forum member
S
Joined: Jan 2014
Posts: 105
PS - this is a Mk III.
The engine I just pulled down was a std 850.

Re: Norton Crank End Play
Samsmc1 #788162 10/25/19 8:35 pm
Joined: Mar 2006
Posts: 4,643
Likes: 26
Britbike forum member
Offline
Britbike forum member
Joined: Mar 2006
Posts: 4,643
Likes: 26
Originally Posted by Samsmc1
I just realized that Norton doesn't suggest a crank end play for their engines.


Originally Posted by Samsmc1
PS - this is a Mk III.


http://britmoto.com/manuals/manuals/850_man.pdf
(copy and paste the complete link or go to http://britmoto.com/ >850 manual)
(pdf p.11)

"Technical Data
Crankshaft
Permissible end Float: 0.010"/0.024"

Originally Posted by Samsmc1
there were no shims behind the main bearings.


That's not unusual.


Last edited by L.A.B.; 10/25/19 8:44 pm.
Re: Norton Crank End Play
L.A.B. #788167 10/25/19 9:40 pm
Joined: Aug 2001
Posts: 3,318
Likes: 12
R
Britbike forum member
Offline
Britbike forum member
R
Joined: Aug 2001
Posts: 3,318
Likes: 12
Doesn't the story go that Nortons assembled the bottom ends without any shims,
they just assumed the parts were within spec

??


Originally Posted by Samsmc1
there were no shims behind the main bearings.

[/quote]
Originally Posted by L.A.B.

That's not unusual.

Re: Norton Crank End Play
Samsmc1 #788196 10/26/19 12:36 am
Joined: May 2011
Posts: 122
J
Britbike forum member
Offline
Britbike forum member
J
Joined: May 2011
Posts: 122
I have seen several engines that ran fine at .020 , but when i set one up i shoot for .010 . I put the shims behind the outer bearing race. Heat the case in the oven and the bearing falls right out. do not ever knock a bearing out cold.

Re: Norton Crank End Play
JakeH #788208 10/26/19 4:32 am
Joined: Aug 2001
Posts: 3,318
Likes: 12
R
Britbike forum member
Offline
Britbike forum member
R
Joined: Aug 2001
Posts: 3,318
Likes: 12
Originally Posted by JakeH
do not ever knock a bearing out cold.


Thats been the golden rule of british motorcycles for at least the past 100 years or more. ??

Vertically split cases (etc) rely on heat for the alloy to expand enough to release their grip on the bearings.
Or the housings belling out or even splitting is a very real prospect.

Re: Norton Crank End Play
Rohan #788223 10/26/19 8:53 am
Joined: Aug 2001
Posts: 8,395
Likes: 39
Britbike forum member
Offline
Britbike forum member
Joined: Aug 2001
Posts: 8,395
Likes: 39
Originally Posted by Rohan
Doesn't the story go that Nortons assembled the bottom ends without any shims,
they just assumed the parts were within spec?


That’s certainly what the “home mechanic” used to do.

There’s a theory that some cranks self-centralise when running, so you can get off with blatantly wrong end float.


Amateur Loctite enthusiast.
Re: Norton Crank End Play
triton thrasher #788243 10/26/19 3:00 pm
Joined: Aug 2001
Posts: 1,394
Likes: 6
D
Crew Chief
Offline
Crew Chief
D
Joined: Aug 2001
Posts: 1,394
Likes: 6
Originally Posted by triton thrasher
Originally Posted by Rohan
Doesn't the story go that Nortons assembled the bottom ends without any shims,
they just assumed the parts were within spec?


That’s certainly what the “home mechanic” used to do.

There’s a theory that some cranks self-centralise when running, so you can get off with blatantly wrong end float.


The NHT crank rotates and tries to turn the oil pump using, Nonparallel, Nonintersecting Axes / Screw Gear, Worm, Worm Gear (Worm Wheel).
That makes the NHT crank screw it's self to the right if there is any resistance to internal oil pump gear rotation caused by oil pressure.
This is what happens since these engine usually have oil pressure.
Shim damage has been discussed for both the crank and case bearings. It is accepted that when the engines run and get hot the mains rotate in the case. The dunstall manual screw fix was one method to stop bearing rotation..
I will not use the case shim method for this reason,. A shim on the timing side is held captive..


dynodave
BSA 3 1961-1963
Ducati 3 1992-2002
Norton many 1951-1975
87 Serv-Equip 100HP MC brake dynamometer,
Re: Norton Crank End Play
Samsmc1 #788247 10/26/19 3:53 pm
Joined: Jan 2014
Posts: 105
S
Samsmc1 Offline OP
Britbike forum member
OP Offline
Britbike forum member
S
Joined: Jan 2014
Posts: 105
The parts book does show the shim, if used; on the timing side.
I hadn't thought about that oil pump, but that's logical if you think about it; the crank has to lean against the timing side bearing because of the worm gear.
I hadn't seen the Mk III service manual (didn't know it existed) until L.A.B. sent me a link to it.
I knew that BSA and several others were anal about end play whereas the older Norton manuals seemed to ignore it.
I did find some other references in factory service sheets on earlier models once I started looking past the 850 and 750 factory workshop manual I do have.
They do show a tighter clearance than the latest Mk III book.
Thanks for all of your input.

Re: Norton Crank End Play
triton thrasher #788268 10/26/19 8:14 pm
Joined: Aug 2001
Posts: 3,318
Likes: 12
R
Britbike forum member
Offline
Britbike forum member
R
Joined: Aug 2001
Posts: 3,318
Likes: 12
There was a story on the NOC Forum that thats how the factory used to do it !
The NOC Forum has been rejigged so many times that unfortunately the links can no longer find anything.

There was also an account there that the crank balancing in the AMC era was done by a contractor, and he just drilled
all cranks to roughly the same set of (random ?) holes in the crank, regardless of the actual weights of components.
Which is fine if all components were identical, and the initial balance was what was required to be mass copied.... ?

Having a lot of end float is said to flog the oil pump drive gear(s) more than is desirable ?
Closing the throttle unloads the contact pressure on those worm gears..




Originally Posted by triton thrasher

That’s certainly what the “home mechanic” used to do.
.


Originally Posted by Rohan
Doesn't the story go that Nortons assembled the bottom ends without any shims,
they just assumed the parts were within spec?


Moderated by  Dave Comeau 

Link Copied to Clipboard
Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | DVD- Manuals & Parts books
Upgrade to: Premium Membership | Gold Membership | Life Membership | Vendor Membership | Site Sponsor Membership


Powered by UBB.threads™ PHP Forum Software 7.7.4