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MG Midget and Sprite Technical - Halfshaft advice needed

I have a 1964 MkII midget with its original wire wheel set up.
I want a spare halfshaft for the car. Presumably I have to get a halfshaft suitable for a wire wheel axle although I see that some companies supply just the shaft. Is the hub detachable on a DIY basis to allow fitting to the shaft or is this not possible?
Also I see Peter May sells halfshafts described as EN24, Moss as Nitrided, Frontline do chromalloy and fine spline.
My engine isn't standard and has a great deal of torque albeit I treat my cars with respect.
Can someone explain these different options please?
Thanks,
Neil
Neil (K series)

The shafts are not interchangeable from steel to spoke wheels as the axle casings are a differant lengths.

I want to say P,M. compition shafts are for steel wheels only...But I maybe wrong

I know the stock shafts for 70-72 steel wheels are supposed to be the srongest made at the factory...You might chech with danial stapleton and see if the spoke wheels shafts for that same period where also the strongest made. if not then what era was the spoke shafts made to there strongest.

Prop
Prop

Hi Prop,
I should add that I have 13" centre lock alloy wheels fitted with 175x70x13 tyres.
Neil (K series)

For steel wheel, BTA806 is the strongest readily available part number (standard from 1967 onwards). Any with ATA serial numbers are early ones and BTA 939 and 940 are the factory competition ones.
If you put a left shaft in the right side it is, allegedly, more likely to fail as they tend to develop a certain amount of 'set' after the first few applications of torque. The same goes for Morris Minor torsion bars. It would work enough to get you home, though.

I have seen a wirewheel shaft that fell out of the hub so they must be an interference fit of some sort. Not easy to do by hand but your average 10 tonne press from Machine Mart will probably do it.

The best tip I ever saw was to have the shaft lathed down in a taper so that the grooves for the splines inboard are level with the OD of the shaft in order that the stresses are rqualed along that area. I'd bet that 99% of breaks occur where the splines just protrude from the diff or where the splines meet the full thickness of the shaft.

Material spec and spline dimensions aren't my area, I'm afraid.


Strangely, I've never seen a broken shaft in the flesh. I guess I'm not trying hard enough
rob multi-sheds thomas

Neil,

IIRC the wire wheel half shaft has a wire wheel hub/spline drive which is pressed onto the halfshaft, the same form of spline at the outer end as the normal disc wheel halfshaft has at the inner end, with a very heavy fit. IIRC the loads required are outside the realms of normal DIY for both disassembly and reassembly.
David Billington

I have a couple of w/w half shafts hubs and carriers, I can let go.

email me if your interested...
K Harris

I have fitted wire wheel half shafts to new hubs numerous times.

They are splined at the hub end as described by David and are indeed a very tight interference fit.

When I first started messing with Spridgets many many years ago I used to fit them using a piece of lead block and a dirty great hammer. If my memory is not too bad the job was reasonably straightforward.

For many years however I have had access to a press and hat makes the job very very easy.

If you are struggling and can protect the threaded end of the hub then hit it home onto the shaft, I doubt this would be very easy at the side of the road though. :)
Robert (Bob) Midget Turbo

I'm thinking that for the purposes of keeping me mobile a long way from home and without workshop facilities it would be better for me simply to obtain a spare half shaft with the hub already fitted. Heavy but convenient.
I didn't realise they were handed.
Neil (K series)

Yes they are handed and that maybe a problem.
It is not the twist that is he problem but the threads on the hubs are left handed on one side and right hand thread on the other. This is so that the wheels tighten themselves up as you drive (maybe) Whether the wrong half shaft fitted for a few miles would come loose or not I would not like to say
Robert (Bob) Midget Turbo

I consider it easier to take a chance and have Peter Best insurance get me brought home in the event of a failure.
Robert (Bob) Midget Turbo

Bob,
You are right and I have continged for that albeit I will be in France this year and I wouldn't want to shorten my hols for the sake of a quickish roadside fix.
Neil
Neil (K series)

Should add that clearly they must be handed due to the way the spinners have to be tightened. I obviously didn't engage brain before typing!
Neil (K series)

In that case then Neil

Having travelled in France extensively I would suggest the following

Take a half shaft and with recovery as part of most insurance policies let them take you to a local garage who I am sure will have no difficulty fitting the new shaft in your axle and will probably not charge you. Love those French!
Robert (Bob) Midget Turbo

That sounds spot on to me Bob. I would then just need one shaft and not worry about the hub part.

It will be interesting to see how the standard halfshafts perform. I know several people who have used the original halfshafts (with K series engine) without a problem but ensuring they avoid enthusiastic wheel spinning from stationary.
Neil (K series)

Hi Neil.
I would remove and check your half shafts before going to France. If they show any signs of twisting or cracking I would replace them. fit hardened half shafts and new hubs for peace of mind


Tim

Tim Dalton

Another thing to check is that the rear wheel bearings don't have excessive play in them. Enthusiastic cornering can break the end off the halfshaft - even a competition one. Don't ask me how I know!
Dave O'Neill 2

Neil,
drop me a mail off board will you,

cheers
Brad_r@fastmail.fm
Brad (Sprite IV 1380)

Hi Tim,
How are you?
You said "fit hardened half shafts and new hubs "

This takes me back to part of the original question:

"Also I see Peter May sells halfshafts described as EN24, Moss as Nitrided, Frontline do chromalloy and fine spline"
What's the difference with these?
Neil
Neil (K series)

Hi Neil

I got mine from magic midget, made from en40 iirc.
Hubs are standard. I had to take them to my local gearbox centre to have them pressed on.
I have been thinking about welding the hub to the shaft but i'm not too sure if this is a good idea.


Tim



Tim Dalton

Neil

The fine spline configuration spreads stress much better. On a wire wheel axle it is a moot point whether it is worth it as the outer splines are still the coarse, square type which focus the stress into the centre of the half shaft, though it is usefully thicker at this end.

Waisting the behined the spline as Rob multi sheds outlined is well worth while. I can send you a drawing if you want.

As others have outlined, they are a press fit into the hub. Our 12 ton press does it with ease.

In my book, you don't carry spare half shaft, you just get good ones to start with - then you don't have to worry. You can guarantee that an old half shaft will break under the most inconvenient circumstances and weather! Our own half shafts for the K Midget (~170BHP) have a fine spline, are waisted, and are made from 2767 and have withstood 8 years of hard competition use, including sutotesting on road legal race rubber such as formula R's.

If this is for your K, then I'd say get some good uprated half shafts then you can forget about them. Because they are simpler to make, special half shafts for wire wheel cars should be cheaper.

Paul Walbran

PAul, could you put a pic of the drawing here?
Not that I have that much power...
Alex G Matla

~~Whether the wrong half shaft fitted for a few miles would come loose or not I would not like to say~~

A good friend of mine fitted wire wheels to his metallic purple morris minor (it was cool back then!)

being young and negligent the righty / lefty requirement was missed and the front hubs fitted the wrong way round. Both wheels were 'scarily loose' 1/2 way through the shake down trip round the block (about 2 miles)

HTH

Rob
robnrrugby

The prices at Magic Midget seem very reasonable compared to some.
Neil (K series)

Rob is right. I recently had to repair the near side back end of an MG TC because the guy had fitted the half shafts on the wrong sides and one wheel undid itself within a few miles. ripped the mudguard off, damaged the inner wing panel. Big mess.

Bernie.
b higginson

Thanks for that confirmation Rob and Bernie

As I stated that is the issue however until now I could only speculate that the wheel would come loose as I have never seen one fitted to the wrong side so have not had direct evidence of the consequencies. Now I know!
Robert (Bob) Midget Turbo

Alex

Here's the drawing of the inner end. (With apologies for the rather evolutionary nature of the drawing!) It is a simple mod to modify a standard halfshaft in this way.

The outer end in our case was made with a non-standard spline to fit a bolt-on flange for steel wheels so is not relevant unless you are going about it as we do - hence I haven't taken up file size by showing it. For the same reason, ignore the overall length dimension of 592mm)

I didn't bother drawing the inner splines themselves as I wanted the drawing to serve for both standard and fine spline halfshafts.

The only problem we've had is the company which does it takes for ever! But the price is sharp and the quality good so we just get a number made at a time.


Paul Walbran

Modifed standard half shaft pictures can be seen at Growler south on this link :

http://rides.webshots.com/album/15283945PMbEoDsIKU

I did my own the same as Growler 2 years ago , it was fairly simple if you have access to a man with a decent lathe and then sent them to be shotpeened after, the total cost was about £40 to do 3 shafts. Still going strong.

Ian
Ian Webb '73 GAN5

Thanks Paul and Ian.
Alex G Matla

This thread was discussed between 31/01/2010 and 02/02/2010

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