MGB compatability

[jA40]

Does anyone have any info on the similarity of MGB hubs/half shafts/diffs/wheel PCD swaps/axle lengths etc?

Once restored, I intend competing with the 1.5, so require uprated brakes.

Firstly, I have noted the similarity to MGB axles  -  BUT, my preference would be to retain the Riley axle. - 
Having already bought & fitted a LSD......
As the PCD of Riley's & MGB's differ I need to focus on achieving a compromise between the two. (Front & rear)
The diameter of the Riley half shaft flange appears too small to encompass the spacing of a MGB wheel.

I've adapted some MGB backplates (rear brakes) to suit a Riley axle, which turned out to be (it HAS to be said) quite an
'involved' process.  Drums still require drilling to correct PCD.

I'm confident that a (re drilled) MGB disc (for the wheel studs) will fit the std hub with a thin spacer, the offset
for a M16 calliper, then appears, just right!

Of the two options  - I have a 'gut' feeling it should be easier to retain the Riley spacing rather than 'move to' the MGB's PCD.
Anyone's experience of similar issues would be greatly appreciated.

Also - does anyone know what the "works spec" was back in the day?

Cheers,   Jeff

[canuck]

Oct 27, 2020 20:57:34 GMT jA40 said:

Does anyone have any info on the similarity of MGB hubs/half shafts/diffs/wheel PCD swaps/axle lengths etc?

Firstly, I have noted the similarity to MGB axles  -  BUT, my preference would be to retain the Riley axle. - 
Having already bought & fitted a LSD......
As the PCD of Riley's & MGB's differ I need to focus on achieving a compromise between the two. (Front & rear)
The diameter of the Riley half shaft flange appears too small to encompass the spacing of a MGB wheel.

I've adapted some MGB backplates (rear brakes) to suit a Riley axle, which turned out to be (it HAS to be said) quite an
'involved' process.  Drums still require drilling to correct PCD.

I'm confident that a (re drilled) MGB disc (for the wheel studs) will fit the std hub with a thin spacer, the offset
for a M16 calliper, then appears, just right!

Of the two options  - I have a 'gut' feeling it should be easier to retain the Riley spacing rather than 'move to' the MGB's PCD.
Anyone's experience of similar issues would be greatly appreciated.

Also - does anyone know what the "works spec" was back in the day?

Cheers,   Jeff

Some thoughts to ponder Jeff,

So yes you are correct, the PCD of the cars is different and one doesn't fit the other, so use of an 'adapter' is required if one is using the same hubs. Similar to (below) but not same as shown.



MGB half shafts are not compatible either spline to spider gear or over all length, so forget about this. 
Keeping the Riley axle is possible however be aware that the Achilles heel being the half shafts, particularly only with 10 splines! . These break with Riley power so any upgrade in power or 'abuse'  will require to upgrade half shafts. (below) 

www.morrisminorspares.com/rear-suspension-axle-propshaft-c87/rear-axle-propshaft-rear-suspension-c88/halfshaft-competition-pair-p831319

I am installing a 18G engine into George and to handle this HP upgrade, (+40%)  I am in search of a MGB rear axle, banjo type (for weight) and steel wheel type for overall width and outer flange/bearing. This banjo axle/steel wheel type will fit for width with caveat being the need to re position the leaf springs perch to fit the Riley location. An easy undertaking and new perch are available, (same vendor above)  if the old don't come off in one piece. Of course with the complete MGB banjo axle, half shafts,  the brakes, and PCD are taken care of.  I imagine the differential ratio of the MGB will be a plus as well. 

I should think I will need to fiddle with the prop shaft, either flange to differential or length and I have not got to this part of the project yet. 

Back to you, I am sure I have left out much, (my memory)  and I did not reference my notes.

Bruce 

[jA40]

Hi Bruce,

Thanks for the info. With regard to the half-shafts, the link you quoted is for "ESM Morris" who I have already used
for various items. They seem very efficient. However, surprisingly the same item from "Peter May" is better value!

An increase to 1800cc may well be option for me in the fullness of time, so I'll start saving up for the shafts.

I believe the MGB diff is 3.09.

All the best with your 'mods'


Cheers, Jeff

[ozieagle]

Oct 29, 2020 9:18:53 GMT jA40 said:

I believe the MGB diff is 3.09.

Actually 3.909. With an 1800 engine and MGB rear end you will get considerably more torque at the rear wheels.

I don't know the Riley's diff ratio, but my Wolseley has a 3.7 in it, as standard. The engine is not as warm as a Riley's, but it still is respectable on the road.

Herb