[skyguy_6153]

Awhile back, I pulled a 2005 Ford Focus MTX-75 from my local picknpull. I wanted to know if the innards of the Focus and Cougar MTX-75 are interchangeable, as if so then I can swap them so I can use the Cougar's CV axles.

 

[B3NN3TT]

There are a couple of variations, so you need to swap like for like. But yeah, otherwise same-ish inside. Focus uses a shorter final drive gear on the diff than the V6 Cougar.

 

[skyguy_6153]

There are a couple of variations, so you need to swap like for like. But yeah, otherwise same-ish inside. Focus uses a shorter final drive gear on the diff than the V6 Cougar.

I'm guessing if I find the right variation, I would just need to swap the differential or differential spider gears?

 

[B3NN3TT]

Yeah the differential ring gear for sure, and I would imagine the matching pinion gear.

Although I just realized I had it backwards - I believe the 4-cylinder uses a TALLER gear than the V6. For an electric, you'd probably want to keep that taller 4-cylinder gearing. It's a popular swap for those who added boost to their V6s and just blew the tires off through first and second; the taller 4-cylinder final drive helped control that a bit, as well as increasing the top speed.

Run a search for "Zetec Final Drive" and see if you can find more relevant discussion from those who have swapped those into the V6 trans case.

 

[skyguy_6153]

Yeah the differential ring gear for sure, and I would imagine the matching pinion gear.

Although I just realized I had it backwards - I believe the 4-cylinder uses a TALLER gear than the V6. For an electric, you'd probably want to keep that taller 4-cylinder gearing. It's a popular swap for those who added boost to their V6s and just blew the tires off through first and second; the taller 4-cylinder final drive helped control that a bit, as well as increasing the top speed.

Run a search for "Zetec Final Drive" and see if you can find more relevant discussion from those who have swapped those into the V6 trans case.

I have ordered the ring gear and differential meant for the Cougar manual transmission (diff. part number for the Cougar is F5RZ-4026-FD, while the Focus diff part number is 1S7Z-4026-B). I still feel like there's an important piece I'm missing for the passenger side of the differential though, as the passenger axle is very odd looking on the end that goes in the diff. side.

 

[B3NN3TT]

That's only half of the passenger's side axle - there's a "mid-shaft" on that side between the trans and the CV axle that mounts to the back of the block with a carrier bearing. So it's basically a 2-piece drive shaft on that side. The part is male on both ends - one end inserts into the trans and the other into the CV joint.

EDIT: the second one up from the bottom is the complete right-side axle assembly for this car.

 

[skyguy_6153]

That's only half of the passenger's side axle - there's a "mid-shaft" on that side between the trans and the CV axle that mounts to the back of the block with a carrier bearing. So it's basically a 2-piece drive shaft on that side. The part is male on both ends - one end inserts into the trans and the other into the CV joint.

EDIT: the second one up from the bottom is the complete right-side axle assembly for this car.

View attachment 82486

Thanks, that clears it up. Kind of similar to my Focus Electric axles, except on the Focus, the end going to the CV axle is female. Also the CV axle snaps in like a socket extension . I found the listing of the second to the bottom axle in your picture, so I guess I'll be purchasing that next week.