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MG Midget and Sprite Technical - Diff planetary gears

I am rebuilding my Sprite Mk 2 diff and ideally want to replace the sun and planet gears.
Can anyone recommend a good source for these parts.
Thanks
Les
Les Robinson

Last time I looked they were NLA. Hardy's in Leatherhead may have a source (for their own rebuilds) but they won't be cheap. Heathrow Transmissions is a better bet, smaller friendlier setup, but again they do rebuilds, I don't know if they'll supply just parts. In my experience the sun gears never seem to wear, and I use secondhand planet gears if needed.
David Smith

I got some last year from MGOC. I don't remember what they cost but even with overseas shipping I think is was about 50GBP.
Martin Washington

Hi Les,

I have lots (perhaps 30 sets or more!) and some are in pristine condition, if you need the 10 spline type. I think some very late diffs might have been about 25 spline. There might be a set of those amongst them too.

Many years ago I used to convert Spridget diffs to fit TCs, so I have a carton full with sets wired together. For the conversion the Spridget sun and planetary gears were replaced with TC / Morris 10 / Y-Type gears.

If you can't find some locally, let me know and I could post a selected set or two. I would be happy with whatever price you think is reasonable (on the cheap end of the scale) plus postage. The problem would be that they might take a while in the post if you are in a hurry to get the diff together.

Yours oTCagonally,
Bob Schapel

R L Schapel

Hi Martin,

Were the gears you got for about 50GBP new or used?

Bob Schapel
R L Schapel

Bob,

They were new.

I just checked and either the prices have gone up or I'm a bit senile (probably the latter). I did get the thrust washers that go with the sun gear also.

Sun gear P/N ATA7037 23.96 GBP x 2

Planet gear P/N 2A7015 15.01 GBP x 2

Thrust washer P/N ATA7039 1.68 GBP x 2

for a total of 81.30 GBP

I'm guessing you'll have to add VAT which I didn't but I got to pay overseas shipping.


One problem I had later on was when I got the "Moss" competition half shafts, they wouldn't go into the sun gears until in ground the splines down a bit. Since the diff was in the car it was easier to grind the shafts. So, I would check your sun gears on the half shafts if you've got everything apart. I don't know for sure but it seems like one vendor went to the high side of the tolerance and the other went to the low side.

Hope this helps.
Martin Washington

Just priced up the gears and thrust washers with MGOC and it comes to £91-74 including postage!!

Martin - what was quality like?

Bob - gears are early type, 10 spline.
I have a contact in Melbourne who might be flying back to the UK on 2 March. Would it be possible for you to post a set to her? What price would you want for a set in pristine condition, including post to Melbourne?
I would rather have a set of genuine parts rather than re manufactured. You can email me on les.sprite@gmail.com

Cheers

Les
Les Robinson

Les, shouldn't you be drinking tea and looking out of your office window at the moment?

Rob
Rob aka MG Moneypit

The gears seemed good although I obviously didn't do a metallurgical analysis. They went in with a nice fit and my old half shafts slid right in. The only problem was, like I mentioned above, when I put in the competition half shafts. I tried the half shafts in an old, worn diff that I had and the old, worn, chipped sun gears and they fit with no problem so my guess is that the splines in the new gear are on the small side. I also measured the new half shafts and the old ones and they were within a couple of thousandths of an inch. And since I didn't want to pull the diff again, I just slowly ground down the half shafts until they fit.
Martin Washington

This thread was discussed between 19/02/2015 and 21/02/2015

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