Morris Minor Owners Club

Hello again ,

Does anybody know about Semi, Three Quarter and/or Fully Floating Wheel Hubs? It's for my work at college and I can't seem to find any definition to it. I've also been told not to refer to Wikipedia due to its unreliable source of information.

Thank you .

Hillier's Fundamentals of Motor Vehicle Technology will have the necessary info ( should have thought your college would have a copy) http://www.waterstones.com/waterstonesw ... 1/4673862/
Was a required purchase on my college course many moons ago

Mogwai wrote:Hillier's Fundamentals of Motor Vehicle Technology will have the necessary info ( should have thought your college would have a copy) http://www.waterstones.com/waterstonesw ... 1/4673862/
Was a required purchase on my college course many moons ago

Ah yes I forgot I was told about that, I ought to buy a copy as I've been told that it has everything I need in it.
Ok I'll try and buy a copy soon, thank you for reminding me .

Found a better link this is the earlier book & has the axle section in a preview
http://books.google.co.uk/books?id=2_QQ ... &q&f=false
go to the rear axle construction chapter

Mogwai wrote:Found a better link this is the earlier book & has the axle section in a preview
http://books.google.co.uk/books?id=2_QQ ... &q&f=false
go to the rear axle construction chapter

Thank you Mogwai, I did have a brief look at the Rear Axle Construction section, I think I ought to buy Hillier's though as I have been informed that it will help me throughout the course, but other than that thank you very much for the help .

Could i just ask for a quick overview of what they are, i'm intrigued..

Me too.

It's the names of the different hub/shaft types commonly found on live axles each with there own pro's & con's
On the semi floating type the bearing runs between the casing & halfshaft with the hub attached to the end of the shaft
The fully floating type has two rows of bearings between the casing & the hub with the shaft passing through it & bolted on the end. this eliminates the bending & shear stresses on the shaft which are present on the semi floating type.
The three quarter one is the type fitted to the Minor, similar to the fully floating but with one row of bearings on the hub this relives the shear stress but still has bending stresses on the shaft

something like that anyway

relives the shear stress but still has bending stresses on the shaft

That's interesting, I think every busted halfshaft I've seen has gone where the splines start which must be the weakest point, and where most bending occurs.

How on earth is there any 'bending stress ' on a Minor half shaft ? Unless the axle casing bends - it's secure inside and certainly doesn't want to bend............It simply transmits torque - and yes it snaps at the stress raiser caused by the start of the splined section.

as there is only a single row bearing on the three quarter axle so the shaft has a role of supporting the hub. the weight of the vehicle is largely taken through the hub & bearing to the axle casing so no sheer stress on the shaft as in the semi floating type but will have a bending stress particularly when cornering

So the bearing is a fulcrum, and the shaft a lever, there must be rather a lot of bending with a knackered bearing.

Even with a new one there has to be some play, otherwise the bearing would be too tight to turn.

Nah - don't agree - the hub is fully supported on the bearing which is perfectly adequate for the job (I've never had one fail) - the shaft fits onto the hub - but does nothing but supply drive to it! It has NO supporting role whatsoever...........

how is a single row bearing alone going to resist all the forces upon it if not for the shaft

Because the bearing has been designed to do so! And it does the job very well - rarely needing to be renewed.

Surely it's a standard single row ball bearing?

Tough call as to which lasts longest out of bearings and halfshafts, for my money it would be the bearings.

yes just a standard single row ball bearing & wont resist all the forces from the wheel upon it alone which is where the shaft comes in to support the hub with the diff effectively forming the inner race.
The only axle type that the shaft has only one job to do (transmitting drive) is the fully floating type as it has two races on the hub.

It's by no means a 'standard' bearing - it's designed to do the job. The shaft ONLY transmits torque............

as you clearly don't believe me that the shaft has more than one load on it here are some links

http://books.google.co.uk/books?id=eL6T ... &q&f=false

http://books.google.co.uk/books?id=U4TB ... le&f=false

http://www.emmbros.com/BlogDescription. ... xle-Shafts

http://books.google.co.uk/books?id=2_QQ ... &q&f=false

http://www.tpub.com/content/armyordnanc ... 660030.htm

Don't take this wrongly mogwai - but I think you need to get out more!

The shaft could only carry bending load if the hub bearing had some 'slop' in it. Any I have checked are very firm............no slop - just as they should be.