Club126UK

Fiat 126 Chat => Fiat 126 Mechanical Problem Solving => Topic started by: dajwid on August 30, 2018, 09:54:15 PM

Title: Bis box in aircooled
Post by: dajwid on August 30, 2018, 09:54:15 PM
I know this has come up in the past, but can’t find it anywhere.
Fitting a Bis gearbox in an aircooled.
If I’m right it has higher gearing top end.
What do I need to change, to make it fit?
I’ve just bought a cheap Bis box that will be stripped .
Title: Re: Bis box in aircooled
Post by: Pete126 on August 30, 2018, 10:17:26 PM
Just the bellhousing  ;)
Title: Re: Bis box in aircooled
Post by: dajwid on August 31, 2018, 07:16:09 AM
Just the bellhousing  ;)

Thank you
Title: Re: Bis box in aircooled
Post by: Rusty's Uncle on August 31, 2018, 07:58:04 AM
I know this has come up in the past, but can’t find it anywhere.
Fitting a Bis gearbox in an aircooled.
If I’m right it has higher gearing top end.
What do I need to change, to make it fit?
I’ve just bought a cheap Bis box that will be stripped .

Unless you have a tuned air cooled engine it will struggle with the higher Bis diff ratio so you might want to use your existing crown wheel & pinion  :)
Title: Re: Bis box in aircooled
Post by: dajwid on August 31, 2018, 08:32:56 AM
Rusty, now it’s getting technical.
The engine will be pretty much standard.
Is there much benefit of the Bis gearbox over the aircooled?
Title: Re: Bis box in aircooled
Post by: Rusty's Uncle on August 31, 2018, 08:46:00 AM
Rusty, now it’s getting technical.
The engine will be pretty much standard.
Is there much benefit of the Bis gearbox over the aircooled?

The actual gearboxes are exactly the same and the parts are interchangeable. It is just the diff and bell housing that are different.
Title: Re: Bis box in aircooled
Post by: 1973/126 on August 31, 2018, 01:49:30 PM
 The bis gearbox is a great upgrade but it only works well with a souped up engine in my opinion. It depends what you want out of your car make it more of a cruiser or usable round country lanes ;D
Title: Re: Bis box in aircooled
Post by: dajwid on August 31, 2018, 07:26:14 PM
Mine will be for around town
Engine pretty much standard
Title: Re: Bis box in aircooled
Post by: Rusty's Uncle on August 31, 2018, 07:37:52 PM
So first question is what is the condition of the original gearbox?
Title: Re: Bis box in aircooled
Post by: 1973/126 on September 01, 2018, 09:21:51 AM
 If you mainly going to use it round town and not planning to upgrade the engine I would just stick with the standard box. I think it is more usable that way.
 You only really benefit from a bis gearbox on the motorway.