Author Topic: Crank end float  (Read 4854 times)

Offline huddie

  • A's Best Friend
  • ***
  • Join Date: Mar 2008
  • Posts: 136
  • Karma: 0
  • wiltshire, england
Crank end float
« on: 17.09. 2012 11:25 »
Hi All, Following on from my topic on Thrust washer debris I am about to rebuild it and was wondering what is the best way to measure crank end float. As one is dealing with a fairly weighty piece of metal where and how does one measure in order to get it right.
Regards Huddie

Online bsa-bill

  • Wise & Enlightened
  • *
  • Join Date: Mar 2006
  • Posts: 5456
  • Karma: 62
Re: Crank end float
« Reply #1 on: 17.09. 2012 15:56 »
A dial gauge is a good buy and not too expensive these days.
Also as has been said on here recently use the old bearing, put the crank in the cases and bolt it up tight ( don't need to use all the studs though ) measure the end float several times until your happy you have a good reading.
Then strip it down take off the old bearing and measure it, then measure the new bearing note any difference and add or take it away from the end float you had established next take 1.5 thou off the said end float and the result will  be the amount of shimming you need to put on the crank before slipping on the bearing.

a case of measure many times and do the job once.
If you have no dial gauge then vernier callipers will do but take many more measurings until your happy, Ive done it twice once with callipers and once with a dial gauige, got pretty good results eventually but it takes patience and time
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline huddie

  • A's Best Friend
  • ***
  • Join Date: Mar 2008
  • Posts: 136
  • Karma: 0
  • wiltshire, england
Re: Crank end float
« Reply #2 on: 17.09. 2012 18:37 »
Cheers Bill, wouldn't of thought of using the old bearing. This way means the new one only being fitted once.
Thanks for that.
Regards Chris

Offline duTch

  • Ricketty Rocketty Golden Flashback
  • Wise & Enlightened
  • *
  • Join Date: Oct 2011
  • Posts: 4540
  • Karma: 41
Re: Crank end float
« Reply #3 on: 18.09. 2012 10:45 »


 I put the bearing inner in place with cases together, used a bit of threaded rod (booker rod?) with a menagerie of  locknuts and washers done up 'tight' against the bearings, then measured the overall, and subtracted the crank width.
 Am yet to see if the results work ok ,
Cheers,duTch
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Online KiwiGF

  • Last had an A10 in 1976, in 2011 it was time for my 2nd one. It was the project from HELL (but I learned a lot....)
  • Wise & Enlightened
  • *
  • Join Date: Feb 2011
  • Posts: 1463
  • Karma: 12
Re: Crank end float
« Reply #4 on: 18.09. 2012 11:48 »
If you have a means of spinning the old bearing inner eg a lathe it does not take much to make it a loose fit on the crankshaft using emery cloth on the bearing inner. This means you can refit the old bearing as many times as you like easily and adjust the shims, all without damaging/wearing the crank.

If the old and new bearings are a different thickness (eg measured from outer face of outer race to inner face if inner race)  due to wear etc this needs to be measured and taken into account but does not prevent you using the "old bearing" method.

Does that make sense? I hope so!
New Zealand

1956 A10 Golden Flash (1st finished project)

1949 B31 rigid “400cc hot rod” (2nd finished project, + favourite bike)

GL1800 Goldwing, well, the wife likes it

KTM 950 ADV, cos it’s 100% nuts

1952 Armstrong Siddeley Whitley for rainy days (with wife)

Online Greybeard

  • Jack of all trades; master of none.
  • Wise & Enlightened
  • *
  • Join Date: Feb 2011
  • Posts: 6185
  • Karma: 35
Re: Crank end float
« Reply #5 on: 30.09. 2012 18:45 »
I've just been setting my crank endfloat. I bolted a piece of steel across the timing case and attached my magnetic dial guage to it. This link should take you to a picture of the operation.

https://picasaweb.google.com/m/viewer?fgl=true&pli=1#share/114671311614255068306/5792056108697841393/5793676310896690338

Neil Ives

Online Greybeard

  • Jack of all trades; master of none.
  • Wise & Enlightened
  • *
  • Join Date: Feb 2011
  • Posts: 6185
  • Karma: 35

Offline huddie

  • A's Best Friend
  • ***
  • Join Date: Mar 2008
  • Posts: 136
  • Karma: 0
  • wiltshire, england
Re: Crank end float
« Reply #7 on: 21.12. 2012 15:34 »
Hi All, Merry Christmas to you all. Long time since I commented on this topic, thats because my crank and relevant bits have been away for dynamic balancing, hopefully to get rid of some of the vibration.
Just put the crankcases back together to check the end float and need a bit of advice.
I have taken the reading several times (properly this time using a solidly mounted dial gauge), and using the old bearing. I was a bit suprised that the end float is showing 0.030mm which is roughly 0.0012". Almost seems like it doesn't need any shims.
Is this usual, and what are the min and max values for end float. Nothing sensible in my Haynes comic.
Obviously I will have to measure the old bearing against the new one and adjust, but if the new one was any thicker than the old one then my endfloat would have all but disappeared, is this ok!
Regards Huddie

Online bsa-bill

  • Wise & Enlightened
  • *
  • Join Date: Mar 2006
  • Posts: 5456
  • Karma: 62
Re: Crank end float
« Reply #8 on: 21.12. 2012 17:10 »
Hi Huddie
Did you have the timing side bush replaced ? I can't recall.
If so it could be the new bush has a bit thicker face - just make sure it is seated right down into the case, careful here use heat on the case and pull the bush in rather that the tempting "give it a tap" method.
Don't know much about the balancing procedure, do they split the crank shouldn't think they need to but others might like to comment here, just wonder if the crank could "grow" in those circumstances.

I'm only a two As guy so can't say what the norm is but my last one had very little clearance, it did need a shim and ended up just on 1 thou so quite possible all is ok, no reason to think BSA couldn't work to close tolerance even all those years ago, if once bolted up it spins free with the old bearing and the new one is no more than 7 thou more I'd be happy, once again there are members who've done this more times than I and no doubt will give more info

edit
OOPS 7 thou more, should have been a decimal point and a couple of zeros in there
sorry
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline duTch

  • Ricketty Rocketty Golden Flashback
  • Wise & Enlightened
  • *
  • Join Date: Oct 2011
  • Posts: 4540
  • Karma: 41
Re: Crank end float
« Reply #9 on: 22.12. 2012 13:42 »
Hiya Huddie, I've been led to believe that's close to ideal, so long as 'all of the above' applies- you might've got lucky!!
 Cheers
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline huddie

  • A's Best Friend
  • ***
  • Join Date: Mar 2008
  • Posts: 136
  • Karma: 0
  • wiltshire, england
Re: Crank end float
« Reply #10 on: 04.01. 2013 18:55 »
Happy new year everybody, Here's where I am with this end float. There was some float, good job I checked again. The dial gauge was moving on the stand bar!!. The thread on the clamp was gone, new dial gauge stand and all, so a delay while this went back to the man'f for replacement. Thought I had it measured right with the old bearing but alas with the new one in plus shims there is still to much float. Now my question is that aiming for about 1.5 thou I am assuming I will need to use a small lever between the crank web and the crankcase or should I be able to move the crank by hand. Also I have been checking the clearance with both the drive side bearing and the timing bush running dry. Should this be done dry or lubed?
Appreciate your help guys because I would like to make sure this is spot on this time.
Regards Huddie

Online muskrat

  • Global Moderator
  • Wise & Enlightened
  • **
  • Join Date: Jul 2009
  • Posts: 8269
  • Karma: 106
  • Lake Conjola NSW Oz
    • Shoalhaven Classic Motorcycle Club Inc
Re: Crank end float
« Reply #11 on: 04.01. 2013 19:54 »
 G'day huddie. All clearances are measured dry. When checking crank end float I do all the crank case nuts/bolts up finger tight, give the cases and crank a few light taps with a hide mallet and turn crank a few times. Give all the nuts/bolts another 1/8 turn and do it all again. Done in a few stages till all done up to about 15ft/lb. The crank should be free to move by hand but a lever can be used as you mention or a light tap with the mallet on the shaft ends just to make sure.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Online bsa-bill

  • Wise & Enlightened
  • *
  • Join Date: Mar 2006
  • Posts: 5456
  • Karma: 62
Re: Crank end float
« Reply #12 on: 04.01. 2013 21:17 »
My last project went drum tight when the studs were turned up leading me to think there was no float, after much faffing about for far too long I discovered there was float and a lot  of it but needed a lever to shift the crank.
Took it back to the shop that line bored it, they got it right second time but wouldn't say what was wrong (obviously I suspect it was not bored true).
Anyway a gentle pry with a bar will confirm the float
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline Slide

  • Moving Up
  • **
  • Join Date: Jan 2013
  • Posts: 12
  • Karma: 1
Re: Crank end float
« Reply #13 on: 05.01. 2013 21:32 »
I used a small strip of metal (see attachment) bolted to one of the oil pump mounting holes. Then I used a set of accurate feeler gauges to measure the end float. Simple, but I found it quite effective and was able to work out the shim thickness quite easily.

For info I've also enclosed a pic of the bearing extractor gizzmo I put together to remove the bearing, rather heavy-duty based on a Clarke bearing puller from 'Machine Mart' in the UK, but it did the job..

Mark
Lambretta LD150 1956 ~6 hp
A7 SS 1958 ~30 hp
Ducati 996 2001 ~ 128 hp

Online muskrat

  • Global Moderator
  • Wise & Enlightened
  • **
  • Join Date: Jul 2009
  • Posts: 8269
  • Karma: 106
  • Lake Conjola NSW Oz
    • Shoalhaven Classic Motorcycle Club Inc
Re: Crank end float
« Reply #14 on: 05.01. 2013 23:45 »
 G'day Mark, that's almost a dead ringer of my puller.
We seem to go to great lengths and delicacy to put them together. But, like jam, if you saw how it was done in the factory you wouldn't eat it. *eek*
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7