Cortina/Capri Rear Ends

angliagt · Post by **angliagt** » Sun Feb 09, 2014 7:16 pm

I have a 2000 Capri rear end on the Ciortina MKII estate -
but it's a 4:56 ratio,& the fuel milage (13 mpg) isn't very good.
I have a Cortina 3:90 unit.Can I swap them out.& keep the
same assembly?

- Doug

Harrie D · Post by **Harrie D** » Mon Feb 10, 2014 4:04 am

Doug

Are you shure about the 4.56 : 1 ratio ?
Which type of Capri rearaxle is it ? Does it have a bolted cover at the back of the diff or can you take out the diff complete at the front ?

Harrie

s2europa · Post by **s2europa** » Mon Feb 10, 2014 1:12 pm

Doug,

Depending on what year Capri the rear end is from (and if it's from a 2.0l), it's a 3.44. The V6 Capris had 3.22. Early 1600 Capris had a 3.89. If the rear end is indeed that high, then it could be from something else. Did you look to see if there is a tag with the ratio on the rear end bolts?

Dan

Harrie D · Post by **Harrie D** » Mon Feb 10, 2014 6:08 pm

Dan

The 4.56 ratio made me think also that it might be something else . Altough there are many more ratio's available for this axle i would not think anything higher as 4.1 would end up in a normal way in USA .
We realy need more info to answer the question .

Harrie

Post by **peteleo** » Tue Feb 11, 2014 3:28 pm

So, Doug. What's the ratio ?... just curious. Pete

angliagt · Post by **angliagt** » Sun Feb 16, 2014 11:38 pm

Pete,

I went out & jack up the estate today,but the results didn't make
any sense.I thought that the driveshaft would turn 4 to 4-1/2 turns of the tire.
Is there a formula for that?

- Doug

enfoprefect · Post by **enfoprefect** » Mon Feb 17, 2014 10:04 am

Put in neutral and jack up one rear wheel. Turn the wheel 2 full turns and count the number of turns the driveshaft makes. That is your ratio.

Post by **peteleo** » Mon Feb 17, 2014 2:44 pm

My Cortina has a 3.9:1. Thus two full rotations of the wheel will give almost 4 rotations of the driveshaft. A bit beyond 4 turns; 4:11 a bit more; 4.44 and so on.
It is difficult to accurately determine the ratio by doing it this way. You may have to remove the back plate of the Atlas R/E and count the gear teeth.