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MG Midget and Sprite Technical - Help! Broken half shaft

This is an utter disaster. My son is getting married on Saturday and plans to arrive at the ceremony in the Sprite. Last night a half shaft broke. This morning the car was towed home, only a mile, and I am now trying to dismantle. The shaft has broken inside the diff and seems to have burred over so it won't slide out. Obviously I can't get the diff out either. If I knock the shaft back home it rotates without driving the diff, if I try to extract it it only comes out about 4mm and jams, and then drives the diff. I suppose I need to lock the diff somehow and use brute force to rotate the shaft until the burrs wear off. Any other ideas?
L B Rose

Take the other half shaft out, insert long bar small enough to go through diff and hammer it out?

Rob
Rob aka MG Moneypit

its likely the shaft has twisted and the splined end won't side out of the sun wheel in the diff. You may get it out by brute force depending on how badly its twisted. The is normally enough tolerance in the splines to get it out. I have successfully levered one out in the past.
Bob Beaumont

Disaster! Sorry to hear it. What a coincidence after I started up a thread on half shafts just this morning. Did I curse you?
Malcolm Le Chevalier

OK I have got it out. Yes the splines were twisted like barley sugar. I did it by hammering cold chisels between the flange and the hub, adding spacers as it came out. This won't have done the bearing any good but I have a new one in stock. Off to Andy Jennings now for another shaft.
L B Rose

Les

were you using the standard Frogeye/A35 shafts, or the later midget ones?
Dave O'Neill 2

Well done!! All the casing and the diff needs is a thorough clean out, new diff and halfshaft gaskets and away you go! make sure the new shaft is marked BTA 806 as they are stronger.
Bob Beaumont

Les,

I have been working on a new rear hub gasket kit which contains a range of gasket thicknesses. The idea being the user can then select a gasket thickness that allows the correct clamping of the shaft/hub/bearing assembly.

I found when doing my rear bearings that the generic rear hub gaskets supplied were generally too thick. This means the rear bearing is not clamped properly and the hub/shaft can move. This translates to the splines moving in/out of the diff, which may contribute to shaft breakage.

It's maybe too late to post (I could post for arrival on Friday), or Wiltshire isn't too far away form me (depending where you are) so I could maybe come down.

Drop me an email if you are interested malcolmlechevalier at gmail dot com.

Cheers,
Malcolm
Malcolm Le Chevalier

Id listen to God on this one

tell your son to run and dont look back

good luck on both accounts

prop
prop

good luck!
Rob Armstrong

L B Rose,

Hopefully your half shaft supplier will have crack checked the shaft if 2nd hand but if not it would be worth your while doing so before doing any further work like Growlerising the shaft. Shot peening would only be of benefit if cracks aren't already present. When I became aware of the cracking problem with the A series half shafts I checked mine in the frogeye and found both visibly cracked with the naked eye but bought the die penetrant kit and checked them anyway to see what it looked like, a good visible die penetrant result and the shafts were scrapped and replaced with later shafts.
David Billington

Dave et al, I was using the later shafts. The early ones I had heat treated still broke. It's all back together now but what a faff. The new bearing, with the same part number on it, refused to fit. It was too tight on the axle. I had to use the old one which seems OK.

Thanks for the offer Malcolm, but I needed the car tomorrow! Crack of dawn Friday I'm off to Essex for the wedding using wedding cars tunbridge wells next day. Just need to pick up the pair of wheels tomorrow morning with new Uniroyals on and put them on the car.

Phew, back to polishing now, and that's another story.
L B Rose

L B Rose,

Odd regarding your new rear wheel bearing as IIRC it is a standard metric bearing made to defined standard tolerances so should be available off the shelf at any bearing supplier. Where did you get it from? I have on the odd occasion seen some Chinese sourced bearings that were well outside standard tolerances built into products but only seen those in the end when they failed and had to be replaced.

Regarding the seemingly odd use of metric bearings in a UK car of the era, I understand that rolling element bearings were originated in Europe and developed with metric dimensions so while inch items were produced the metrics prevailed and were cheaper as more were produced. A guy I used to know noted that a UK Scammell truck gearbox of the 1930s was produced to inch dimensions but used metric bearings, he tracked down the designer, still alive at the time and asked why metric bearings as was told cost, metrics were cheaper and just as good.
David Billington

David - the bearing came from Moss Europe I think, or possibly AH Spares. Had it for years though! As I clamped it up the inner race seemed to expand and locked the whole thing solid.

Bob - that was a good idea but (a) by the time I saw it I had succeeded, and (b) I didn't have a suitable bar.

BTW my name is Les but I can't find a way to change it on my profile!
L B Rose

Update: It was all back together and working fine by Wednesday evening. The old hub bearing has no play and is totally silent. So far so good....

Then on Thursday evening the head gasket blew. Amazingly the grapevine located a new gasket at 9pm and the job was finished by 1045. In the morning the engine was warmed up, nuts retorqued and valves reset, and I sped off to Essex without missing a beat. The car did its bit at the wedding, looking very odd parked next to the bride's Bentley. I was still spraying paint on it on Tuesday afternoon. What a week.
L B Rose

LB

HAHA... great story thanks for sharing.

these cars arw just possessed... if you had hair before ownership you dont now...its alays a fight with these cars

just because its running right now dosnt mean it wont go down in 10 minutes

It seems you just have to be willing to force your will upon them and say it will run or jesus will cry tonight... and just muscle your way thur it


congratz... im glad it worked out for you.

prop
prop

It reminds me of the old adage "how long does it take to prepare a race car? One day longer than you have available!"
Except on this occasion you made it to the line, well done!
Paul Walbran

Oh dear, it sounds like I have the exact same problem! Half shaft is stuck fast!! Tried levering it off, and have knocked the studs out already thinking that may give it enough play to get it out... Tried a bar from the other side but the bar was too weak and just deformed although I'm not 100% I was on the end of the half shaft...

Any other tips?
S J Dodd

If all else fails, I do recall one occasion when the owner cut a hole in the back of the diff housing (later welded up) to cut part of the broken bit off and out of the way, allowing the rest to come out with the diff.
Paul Walbran

This thread was discussed between 18/05/2016 and 03/06/2016

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