After finally pulling my gearbox apart I have removed most of the gears and bearings from the motion shaft. On inspection most of the cogs look good, no damage, no pitting except two!

The first one I think is part of third gear! One tooth has snapped! Plus I can't get the pegs or plunger things in to remove the thrust washer! Any suggestions?




Secondly the Final drive pinion has three teeth in a row damaged! Where's the best place to find replacements of these two parts?



P.S. They are clean, it's the light that make them look rusty!!

P.P.S. The baulk rings all look fine, should I replace them as a matter of course?

To be honest , if the rest of that 3rd gear is like all the other teeth, & only that one dog has chipped off
then i`d re-use it, shouldn`t be an issue at all
the pinion doesn`t look too bad either really, but i can`t really see the whole thing so it`s a bit hard to tell,,, ive seen way way way worse in a mini & still going ok

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Pinion damage is often caused by people when using a cold chisel to flatten the locktab. You need to be careful to keep pressure off the teeth, they are brittle.
I's use the 3rd gear but find another pinion, and a crownwheel too if it's marked.

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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.

With Regards to the pinion, The crown wheel is not as wide as the pinion
You should be able to see where the two have meshed, if the damage is
outside of this area, then I would suggest You can use it without problems.
In my opinion when ever a gearbox is rebuilt care should be taken to mesh
the crown wheel and the pinion back the way they have been running before,
Some people may disagree with this,
the other thing I noticed is the amount of teeth on the pinion
I cannot remember if You mentioned what car this is going in

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" A Hundred Years From Now It will not Matter what my Bank Acount Was,
The Sort Of House I Lived in, Or The Kind Of Car I drove ... But The World May Be A Better Place
Because I was Once Important In The Life Of A Child"

Cheers guys great advice

Looks like I'll need to find a new pinion I suspect you are correct, I think it could have been my Neanderthalic removal that caused the damage! The crown wheel is fine.

The pinion has 15 teeth and the gearbox is going onto a 1275 that I'm attempting to rebuild! That will be fitted to my 78' Leyland.

If it's only 15T, the diff ratio is either 4.13 or 4.26.
Way too short gearing for a 1275 in a road Mini, IMO.

I'd look for a 3.44 (18T/62T)

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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.

Thank you

Just about every rodchange box (except Moke) had a 3.44 diff in it.
Fit pot joints whilst you're about it.

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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.

This is why I mentioned the Pinion to You, with 10inch wheels
it will get of the mark quick, but will run out of legs pretty quick as well
There is one more ratio with a 15 tooth pinion that I can recall 4.33:1
so they are 15/62 15/64 15/65
4.13 4.26 4.33

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" A Hundred Years From Now It will not Matter what my Bank Acount Was,
The Sort Of House I Lived in, Or The Kind Of Car I drove ... But The World May Be A Better Place
Because I was Once Important In The Life Of A Child"

It's 15/64 (4.26) and I'm running 12 inch wheels.

At 113kph you will be doing 5000rpm.
It is a silly diff for any road Mini.

What would people recommend?

Mostly daily driver with occasional highway runs

3.44 will be the best compromise for a daily