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MG Midget and Sprite Technical - Ford diff

I read something somewhere on 't internet that a common mod was to fit a ford diff in a midget axle. Does anyone have more information on that? Only reason for asking is my diff is shot and a ford diff might be a cheaper option.

J White

I know of Midgets with Ford axles but never heard of a Ford diff in a Midget case.

Good secondhand Midget diffs are still fairly cheap and they are always coming up on ebay or our classifieds.

What ratio are you after?
John Payne

I thought it more likely they meant an axle swap but needed to check.

Well I've got a 1500 Midget so I suppose I should have a 3.7
Would a 4.2 make much difference as they seem to be a lot cheaper (like 100) from what I've seen. From my calculations it would take 10mph off the top end but I bet the acceleration would improve somewhat. Oh and I don't do a lot of motorway miles, much prefer a twisty back road.

J White

J White,

IIRC Mallock and possibly others modified the A series axle to take a Ford final drive. A quick search on "Mallock Ford diff" turned up a mention of re-drilling the casing to take the final drive and adding a spacer to get the centre line correct.
David Billington

How does the ford diff, mate to Spridget halfshafts?
Lawrence Slater


One of the points of the conversion was to use the stronger spline design of the Ford axle. IIRC someone I spoke to years back mentioned welding the Ford spline onto the BMC halfshafts, other than that you would have to get specials machined.
David Billington

Would be worth doing if it kills the whine forever, and you can do wheel spins without worrying about snapping a h/shaft. Althogh, amazingly, I have a spare I've never used. I've never actually broken a shaft on the sprite. Touch wood.
Lawrence Slater

Well seen as money is tight at the moment I think I'll just have to get a 4.2 diff to get it on the road.
J White

"Well I've got a 1500 Midget so I suppose I should have a 3.7
Would a 4.2 make much difference as they seem to be a lot cheaper;

Putting a 4.2 in a 1500 is just about the WORST thing you can do vis a vis engine life!

The 1500 does NOT like high rpms in stock form.
Deborah Evans

I know but at this point I don't have much choice. It will (hopefully) only be for a couple of months and I'll be doing town driving all that time.

From what I've found it's 95 for a 3.9 diff and 135 for a 3.7 both are out of my budget at the moment.
J White

J white -- would you like to borrow one for a few months?
I am in Leeds
Mick - still wiring!!

It would be a MASSIVE help if you have a spare. I know they're supposed to be good for 150K miles but mine seems to have died early at 102K.

When things improve at work I'll have the money for one. Motor trade has gone very quiet, no one is buying classic mini's at the moment.
J White

<much prefer a twisty back road>
If thats the case and your not up and down the motorway everyday you will probably find you enjoy a 4.2 diff better than your old one and its a lot cheaper(the secrets out!)
You would find it hard to notice the difference between a 3.9 and a 4.2.
You have a rev counter so just keep an eye on it.

I have a 4.2 in my Turbo and I love it, just keep a 3.9 incase I do any touring.

If I was you take out your old diff and find out whats in there, it could be 3.7 or 3.9 and if someone else has already changed it you never know you might already have a 4.2 fitted by po
Good luck
Rob Newt

j White -- mail me

news56 at hotmail com
Mick - still wiring!!

Good idea on the checking front Rob. It needs to go on stands to do some welding so while I'm about it I'll take the diff out and check. It's got to come out anyway as the damn thing whines like a spoilt brat.

A 4.2 is looking a good choice for now. I'll have to restrain myself in the revs department....difficult when you're used to driving a Mini....those a series engines love to rev. As it's winter and I've just rebuilt the engine that'll help. I can behave when needed.
J White

As I recall the ratio is also stamped on the outside of the diff casing on the ali casing perimeter.

richard boobier

Should have bought an A series midget then ;P
Onno K

lol @ Onno. I know, I work with Mini's. It would have been soooo much easier and cheaper for engine parts.
J White

?Iv got a ford anglia axle on mine , and i put it on before i bubble arched the rear arches , and i could fit a 5"x13 wide wheel with a 165 x 80 (normal profile ) tyre on quiet easy
Darren 2litre frogeye

So - what are you expecting to pay anyway?

Says she with a couple of diffs lying around, but needs a decent bribery amount to part with them ... ;)

Hi Darren
I also fitted an Anglia axle
I used 105e Anglia housing/axles/brakes and a 3.7 lsd centre from an Escort
Used a red hot 2.3 litre b series engine and gave it hell -- never had a problem with the diff, I reckon it is the best conversion to do -- trouble free
Cheers Willy
William Revit

lol @ rachmacb

Well I was hoping to pay a decent chunk less than the prices I put. Christmas and MOT approaching fast means I HAVE to keep the costs down.....especially if I don't want to spend all Christmas in the dog house :D
J White

call Mallock sports cars, there is a way to mount a ford diff to an mg casing, they have this adapeter sorted already. call them for more deatils, cant be any more specific than that!

WDT Corry

Here you go, read this. Loads of conversation about this.
Lawrence Slater

"Motor trade has gone very quiet, no one is buying classic mini's at the moment."

Depends what you call a 'Classic Mini'...

If Mk1 Minis are cheap at the moment, I'd be interested in buying a few more.... :-)

M T Boldry

lol. Yeah well Mk1's are few and far between. Mainly Mk2's onwards....They're all classic....and still selling slowly.
J White

This thread was discussed between 10/12/2011 and 27/12/2011

MG Midget and Sprite Technical index

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