some persons sell front diff for 4x4 and say that is for a 3,9 ratio (i understand that is of a xr4 4x4 or similar car) but only with the front diff i have in my sapphire cosworth a 3,9 ratio? or the only way to have it is to change the two pinions and cut the chain of the transfer box?

and in that case one front and rear 3,9 ratios of 4x4 xr4 resist 300bhp of a cosworth?

thanks people

 

Sapphire cosworth diff ratios are 3.64:1
The V6 sierra's(4x4) were 3.62:1
tabetha

 

yes i know it but if i change only the front diff i change the ratios?

 

Hi,

You can't change only front ratio (or only rear ratio) : Your central LSD rapidly burn and diff too.

Front and rear ration must be same, EXCEPT if you change in same time the central dispatching ratio between front and rear axles. (2 pinions with chain)
But these pinions are expansive and difficult to find.

Anyway, 3.9 is a very good compromise to obtain good acceleration and good max speed, instead 3.62 or 3.64 stock ratio (2wd or 4wd).

Regards.
Claude

 

if you put a 3.9:1 rear diff in then i can sort you out with some step offfs (pinions) and chain to match the 3.6 front for your transfer box ?

 

the question is: can i put ONLY the front and rear 3.9 diffs and expect it to work good?

 

it would work yes.

 

From what car do I get a 3.9 front diff? Where was it build in?

 

Sierra Sapphire 4x4 with 2.0 DOHC engine.
In Your country on Switzerland You should find one without big problems, they are versions for mountain countries...
regards
maciek

 

Hi, I've posted loads of info on the Sierra Front Diff :
http://www.super7thheaven.co.uk/Sier...t_Differential

http://www.super7thheaven.co.uk/blog...ntial-a41.html

There should be loads of info on what cars they come from, part numbers, exploded diagrams etc.

My Sierra 3.92:1 tag reads:
V90BB AA C9P5A CG02It came from a Sierra Sapphire 4x4 GLS 2.0i DOHC if that is of any help.
The FINIS number for the 3.92:1 is 1661121