Technical Different gear ratios in different gearboxes?

[RedPeril]

I'm searching for a replacement gearbox for my Punto and have found a few on the internet. Adverts usually state the specification of the gearbox and the car that it came from. I have found that some sellers have a "Check if it is compatible with your car" selector. When I have used the selector at times it has come up with a negative for a gearbox advertised as the same as my faulty one.

So hence to my post. I got to thinking, is this about the gear ratios in the gearbox? A diesel engine has a different power curve to a petrol one so you would expect the designer to take this into account when calculating the gear ratios in the gearbox? A so-called sports version of the car might be expected to have ratios that give better acceleration but it might not perform so well when loaded to the gunnels with building materials.

So my questions are:

1. Do gearboxes from the same model have different gear ratio variants?
2. If yes, then does it make a significant difference when buying a replacement?
3. Have I got this wrong and are there other factors to be considered?

I have a:
Fiat Punto Grande;
1.4L (1,368cc);
8 valve;
77BHP;
Petrol;
Nov 2009 reg.

Any thoughts or information would be helpful.

 

[GrandePunto PL]

Overthinking. Just match the car model ("Grande") and engine ("1,4 8V"), that's all.
1. Yes, it is possible.
2. No, it doesn't make any difference for average user.
3. The real problem is the condition of the "new" gearbox. Which you cannot tell really (by eBay pictures).
Will see (after you install and test drive it)...
4. Consider brand new clutch set (everything, clutch, release bearing, fork and its bushings, and maybe clutch slave if it's leaky).

 

[bugsymike]

Overthinking. Just match the car model ("Grande") and engine ("1,4 8V"), that's all.
1. Yes, it is possible.
2. No, it doesn't make any difference for average user.
3. The real problem is the condition of the "new" gearbox. Which you cannot tell really (by eBay pictures).
Will see (after you install and test drive it)...
4. Consider brand new clutch set (everything, clutch, release bearing, fork and its bushings, and maybe clutch slave if it's leaky).

As has just been said.
Re eBay I suggest you contact the seller and ask if it will fit your vehicle , including reg.number etc. If he says it will and you find it won't you have recourse through eBay, which is a lot harder if you don't as he will say you chose it by clicking BUY! Also try and fit it right away, chances of a refund several weeks later are slim!!!

 

[RedPeril]

Overthinking. Just match the car model ("Grande") and engine ("1,4 8V"), that's all.
1. Yes, it is possible.
2. No, it doesn't make any difference for average user.
3. The real problem is the condition of the "new" gearbox. Which you cannot tell really (by eBay pictures).
Will see (after you install and test drive it)...
4. Consider brand new clutch set (everything, clutch, release bearing, fork and its bushings, and maybe clutch slave if it's leaky).

Thanks for your reply GrandePunto PL. Overthinking? Probably, it's the sort of person I am! On the other hand, I hate getting into these things arguing backward and forwards, especially for such a big thing to pay carriage for. Thanks for the suggestion for a new clutch set. I'll price it up.

Overthinking. Just match the car model ("Grande") and engine ("1,4 8V"), that's all.
1. Yes, it is possible.
2. No, it doesn't make any difference for average user.
3. The real problem is the condition of the "new" gearbox. Which you cannot tell really (by eBay pictures).
Will see (after you install and test drive it)...
4. Consider brand new clutch set (everything, clutch, release bearing, fork and its bushings, and maybe clutch slave if it's leaky).

Thanks for your reply bugsymike. I've got a mechanic lined up so I should know if it works a day or two after delivery.
As has just been said.
Re eBay I suggest you contact the seller and ask if it will fit your vehicle , including reg.number etc. If he says it will and you find it won't you have recourse through eBay, which is a lot harder if you don't as he will say you chose it by clicking BUY! Also try and fit it right away, chances of a refund several weeks later are slim!!!

 

[RedPeril]

Overthinking. Just match the car model ("Grande") and engine ("1,4 8V"), that's all.
1. Yes, it is possible.
2. No, it doesn't make any difference for average user.
3. The real problem is the condition of the "new" gearbox. Which you cannot tell really (by eBay pictures).
Will see (after you install and test drive it)...
4. Consider brand new clutch set (everything, clutch, release bearing, fork and its bushings, and maybe clutch slave if it's leaky).

Thanks for your reply GrandePunto PL. Overthinking? Probably, it's the sort of person I am! On the other hand, I hate getting into these things arguing backward and forwards, especially for such a big thing to pay carriage for. Thanks for the suggestion for a new clutch set. I'll price it up.