15 replies to this topic

[nikollou]

Hello,

 

I am currently rebuilding the transmission of my mini and as per the title I noticed that there is a chip on one of the teeth of the Input Gear:

 

 IMG_7425.jpeg   41.89K   6 downloads

 

 IMG_7426.jpeg   45.34K   5 downloads

 

Since the cost of a new gear is quite hefty and the project has already gone a few times over budget, I'd like to know if I can use it in this state or if I am risking gearbox failure.

 

Any advice would be welcome.

 

Thanks in advance,

Nik

[Dusky]

Probably could,id never do it.
Maybe guessworks has a good used replacement?

[Spider]

If it's not some road burning car / engine, that should be OK.

I'd suggest polishing the chip though.

[DeadSquare]

There is one on ebay for £7-00, but it in Greece.

[DeadSquare]

Classic Mini 1st Motion Gear Shaft Drive 24 Teeth 22G 849

Pre-owned

See more like thisClassic Mini 1st Motion Gear Shaft Drive 24 Teeth 22G 849

Free returns

• £7.00
•  
• + £9.57 postage
•  

• From Greece

[antcole]

Personally, id re-use it.

Unless i had the option of another one handy, but as Spider said, dress up the edges with a decent oil stone or gently with a dremel.

 

If you have access to some dye-penetrant crack detection spray, you could check to make sure there are no fine cracks on any other teeth or further on that tooth.

 

https://www.millenni...spray-727-p.asp

[Spider]

Classic Mini 1st Motion Gear Shaft Drive 24 Teeth 22G 849

Pre-owned

See more like thisClassic Mini 1st Motion Gear Shaft Drive 24 Teeth 22G 849

Free returns

• £7.00
•  
• + £9.57 postage
•  

• From Greece

 

 

His is a 29 tooth,,,,,

[nicklouse]

 

Classic Mini 1st Motion Gear Shaft Drive 24 Teeth 22G 849

Pre-owned

See more like thisClassic Mini 1st Motion Gear Shaft Drive 24 Teeth 22G 849

Free returns

• £7.00
•  
• + £9.57 postage
•  

• From Greece

 

 

His is a 29 tooth,,,,,

 

now i want to know how you know that?

i had a look at the picture and thought it is going to be more than 24 but said nothing as i was not 100% sure and IIRC there are only the two sizes?

[ACDodd]

Actually you all missed it, it's a 28tooth economy input.

If it's a standard rebuild, simply stone the edges and it will be fine. Guessworks is you best bet for a good used replacement.

Ac

[nikollou]

Hi all,

 

thank you very much for your replies!

 

@DeadSquare - thanks for the post, funny enough I am based in Greece so that would have been a great opportunity but as other noted it is not the right part number.

 

My engine will be a mildly turbo'ed fast road build used as a daily driver so I am not going purely "stock" but at the same time won't be boosting like crazy and squeezing every ounce out of those 1275cc's.

 

@ACDodd thanks for pointing that out, I was not aware that this was an economy version but after looking at minispares I confirm that the groove in the shoulder of the gear indicates it is the 28 tooth model. 

 

-So this means that my gearbox has overall higher gearing than a standard Mini one?

 

I have already opted for a 3.1 diff and I will be using 10 inch wheels (the rationale being that the increased torque from the turbo would help with acceleration and at higher speeds the car would become more drivable since I will use it as a daily driver).

 

-If my gearbox is also geared higher am I possibly going a bit too far with all these combined?

-How different is this economy model to the standard?  

 

Any opinions would be more than welcome.

 

Cheers,

Nik

Edited by nikollou, 06 November 2018 - 08:15 AM.

[ACDodd]

It will raise your effect FD ratio from 3.105 to 3.001:1.
The question is what primary gear have you got fitted, the stock 29tooth or the 30tooth economy one?

Ac

Edited by ACDodd, 06 November 2018 - 12:45 PM.

[nikollou]

Great thanks ACDodd, I'm not sure to be honest so I'll have a look tonight and loop back with my findings.

 

Nik

[DeadSquare]

Hi all,

 

thank you very much for your replies!

 

@DeadSquare - thanks for the post, funny enough I am based in Greece so that would have been a great opportunity but as other noted it is not the right part number.

 

My engine will be a mildly turbo'ed fast road build used as a daily driver so I am not going purely "stock" but at the same time won't be boosting like crazy and squeezing every ounce out of those 1275cc's.

 

@ACDodd thanks for pointing that out, I was not aware that this was an economy version but after looking at minispares I confirm that the groove in the shoulder of the gear indicates it is the 28 tooth model. 

 

-So this means that my gearbox has overall higher gearing than a standard Mini one?

 

I have already opted for a 3.1 diff and I will be using 10 inch wheels (the rationale being that the increased torque from the turbo would help with acceleration and at higher speeds the car would become more drivable since I will use it as a daily driver).

 

-If my gearbox is also geared higher am I possibly going a bit too far with all these combined?

-How different is this economy model to the standard?  

 

Any opinions would be more than welcome.

 

Cheers,

Nik

 

 

Don't worry.   Your final drive gear ratio will be quite OK.

 

 

 

 

 

 

Going down hill  !

[nikollou]

It will raise your effect FD ratio from 3.105 to 3.001:1.
The question is what primary gear have you got fitted, the stock 29tooth or the 30tooth economy one?

Ac

 

OK I had a look at my primary gear and indeed it is the 30 tooth one. So what is the consensus on this setup?

Am I good to go like DeadSquare suggests? Or would I possibly end up with overly long gearing?

 

Some engine specs to help guide any feedback:

• 1275 +0.20
• Omega 14cc dished pistons
• SW5-07
• 9.5 comp ratio
• HIF44 carb
• T25 Turbo @ about 7psi (no intercooler setup - like metro turbo)
• Ported Cyl Head with 35.6 & 29.2 valves

 

Thanks,

Nik

[mini13]

as this is a turbo motor I wouldnt chance it, I'd look for a set of 1:1 gears,

 

Also, do you mean 9.5:1 comp ratio as that sounds a bit high with no intercooler,