Hi all

I am hoping someone here can clear the numbering of gearboxes up for me.

I have a Cooper S gearbox, casing number is 22G1128, what makes this a Cooper S box Is it the external number or simply what is in the casing

Similarly, I need a gearbox for my '64 Cooper, I believe this should be a 22G68 casing number but I've heard of this number coming from a deluxe and Morris 1100 as well.

Please help me understand.

Cheers
Steve

The casting number is just that, a number to identify the casting. A few different cars may use the same casting.
What counts is having the correct internals inside the correct gearbox case.

22G1128 box is used on Mini-K, Mk2 Cooper S, Clubman GT and Clubby 1100 up to 1973 approx.
What makes a Cooper S/GT box is they have Hardy Spicer U/Js, the others had rubber couplings.
Also the 1st motion shaft and cluster gear (laygear) are different, so 1-2-3 gears are slightly higher gearing.

22G68 box casing was used on many things including 997 & 998 Cooper, and the Mini Deluxe.
The Coopers had different gear ratios.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Hi

Ok, that all makes sense.

Now for the next question.

If I got a 22G68 casing, can I then put the right internals in it to make a Cooper 998 box and if the answer is yes, is there something around to tell me what the right internals are and would they be available

Cheers
Steve

It gets messy with that 3 synchro case, if it's got A type gears now you need the full Cooper gearset and mainshaft, to convert it to B type Cooper gears.
Most of this stuff is now NLA (no longer available).

If it has B type gears already (with needle rollers inside 2nd & 3rd gears)
you will need the Cooper 1st motion shaft, 3rd gear and a 22G1100 cluster gear.

Personally, unless running in Nb racing I'd fit a 4 synchro box- gears etc are much easier to get.
All it takes to convert a Mini-K box to S box ratios is a 22G1371 1st motion shaft, and a 22G1040 laygear.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

not sure what your intentions are but I / will be staying with the 22G1128 for my Cooper S Motor

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Stop Licking the Dog...I Don't Care Who Started It

"If it has B type gears already (with needle rollers inside 2nd & 3rd gears)
you will need the Cooper 1st motion shaft, 3rd gear and a 22G1100 cluster gear".


Hi

I am still thinking of getting a deluxe gearbox with the 22G68 case number and "making" it into a Cooper by doing the above. What I would like to know now is if the bits mentioned above would be available

Cheers
Steve

I say don't bother with 3 synchro always crunch in first unless you double clutch into 1st. I use first often when say aproaching a round about so it would effectly cut down the usage of your gearbox by 25% (1 gear out of 4).

If you are going to the trouble of building a "cooper" ratio box, why not just get your hands on a 4 synchro 12g1128 box and buy the laygear and 1st motion to conver it into a Mk2 Cooper S box? This is exactly what I did and (although I have not yet driven it) I like the results so far.

Also the diff ratio may be shorter (like 3.67) on a 3 synchro box and may not match your current speedo which means it may read wrong. I think a well tuned mini runs well on 3.44 (S Diff) as it has something to pull against and it is a good compromise for cruising at highway speeds vs taking off....

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Lillee - 1969 Morris Mini K

Not only are 3 synchro box parts much harder to get now, the box is not as strong.
Fastest moving gearbox item back in the `60s was new 2nd gears, and cluster gears.. I know, my bro sold em, and I bought em!!
And I also had a brand new 998 Cooper 1st gear go BANG! the first time I nailed it...

Mini K/Clubby 1100 remote box is well worth it, they are cheap as chips now. Who would want a non-synchro 1st gear these days.
To make it S ratios, only 2 gears need to be changed. And yes you can still get em.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I know it's not everyones cup of tea but I want to restore this Cooper to original, so really want the correct gearbox in it.

I take it from your comments that the bits I would need for the 22G68 box would be very hard to find

Steve

Doc do you mean the case or just the internals? Would the 4 speed synchro guts fit into a 3 speed box?

As I have mentioned elsewhere I would like to put the Magic Wand gear lever back for the full MKI "look" Now I can try to change the diff housing over (if it lines up) but as I'll be pulling the 4 speed apart a bit to u/haul it would it be another approach to drop it into the 3 speed box?

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David L


My greatest fear in life is that when I die my wife will sell my Mini and tools for the price I told her I paid for them!

OK I was just about to say that that would be the ONLY reason you would want a Cooper 3 synchro box. In which case go for it...

Yes you can convert any 3 synchro to a cooper box by changing gears but not sure if they are available anymore. It wouls be easier to find a cooper box, I know where there are at least 10 of them

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Lillee - 1969 Morris Mini K

Chong; If you're not talking about me I want to know where please!!



Graham

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Sir Alec! we are not worthy!

Graham I AM talking about you you goose! I know noone else as obsessed with Coopers as you are

When i said 10 I didn't specify if they were inside of cars or not

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Lillee - 1969 Morris Mini K

Oh! OK! Good! I thought so!

I probably have about 8, but most pretty poor condition, as has been said, parts are nigh impossible to find, I have lost track of how many boxes I have counted the teeth on trying to find the holy grail!

A good compromise would be a 3 sync straight cut gearset in a 22G68 box, I believe these are still being made? the ratios are good and the gears aren't too noisy, most of the whine comes from straight cut drop gears.

The gearboxes were really the weak point of 997's not too sure on 998's but I would guess not much better.

Depends on how close to original you want to be! Would you put back in a coil spring clutch?

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Sir Alec! we are not worthy!