Fox T-Bird/Cougar Forums

Technical => Drivetrain Tech => Topic started by: BillWert on November 21, 2006, 12:42:13 AM

Title: T-Bird vs. Mustang rear end
Post by: BillWert on November 21, 2006, 12:42:13 AM
I read on Coolcats that TBirds, Cougars, and Mustangs all used the same rear end until mid-85.  I've got an 84 T-Bird with a 7.5", and I picked up a rear end out of an early 85 Mustang (also 7.5").  The date code on the Mustang rear is 5D27, which I believe translates to April 85. 

We got the rear end out this weekend and got to measuring, and realized that the T-Bird rear is 0.75" wider on each end axle to axle.

Does anyone know what gives?  I thought they were supposed to be identical, so I'm kind of bummed.  I'm still going to put it in because I want the locker, but now I have to use wheel spacers or something. :(
Title: T-Bird vs. Mustang rear end
Post by: SLEEPER T-BIRD 87 on November 21, 2006, 12:57:41 AM
T birds used longer axles. the housing should be identicle
Title: T-Bird vs. Mustang rear end
Post by: BillWert on November 21, 2006, 01:05:18 AM
Aah. So the mid-85 switch was just to lengthen the housing so they didn't need the offset brake drums any longer?

Bah.  Besides spacers do I have any options?
Title: T-Bird vs. Mustang rear end
Post by: Chuck W on November 21, 2006, 07:07:00 AM
Take the axles and brakes off the Tbird rear end and put them into the Mustang one....simple enough...
Title: T-Bird vs. Mustang rear end
Post by: Ether947 on November 21, 2006, 07:07:18 AM
Swap your brakes/axles over. Problem solved.
 
Dangit Chuck! :grinno: Had I not been eating I would have beat cha!!!
Title: T-Bird vs. Mustang rear end
Post by: BillWert on November 22, 2006, 09:37:33 PM
Aah - I got it.  I went out today and pulled the axles out and it does look like they'll swap fine.  You guys mentioned swapping the brakes, and obviously the drums are different, but do I have to swap the backing plates too?  I notice the lip of the plates on the Bird plates are a little thicker but it seems like the rest of it is similar enough to stay.  What do you guys think?

Thanks!
-Bill