Fox T-Bird/Cougar Forums

Technical => Drivetrain Tech => Topic started by: Grumbles on March 20, 2009, 05:35:44 AM

Title: 83 Heritage Tbird rear end.
Post by: Grumbles on March 20, 2009, 05:35:44 AM
What did this car come with stock?  Haven't really taken a peak, some websites say traction-lok, some say that was only in the TC.  Is it a 7.5", 8.8", 9"?  I haven't the slightest clue lol
Title: 83 Heritage Tbird rear end.
Post by: Thunder Chicken on March 20, 2009, 07:51:41 AM
Traction lock was optional in all models except the TC (it was standard in the TC). It would be a 7.5" rear. You should be able to tell what gears and diff are in it by looking at the door tag and comparing the axle code to this:
http://www.coolcats.net/tech/general/axleinfo.html
Title: 83 Heritage Tbird rear end.
Post by: Grumbles on March 26, 2009, 10:04:00 PM
So as established in a thread in the lounge, mine isn't a locker.  Can locker guts from a 7.5 be transplanted in without significant modification?  I know very little about this topic, any info at all is helpful.
Title: 83 Heritage Tbird rear end.
Post by: Thunder Chicken on March 27, 2009, 08:38:51 AM
Locker guts from a 7.5 will bolt right in, but you've got to do the whole "setting up the rear" thing (setting backlash, preloading the pinion, making sure the ring & pinion teeth are meshing where they're supposed to, etc). It's not a job for the unskilled. Hell, I'm a licensed mechanic and I would balk at doing it...
Title: 83 Heritage Tbird rear end.
Post by: 83-88T-Bird Guy on March 27, 2009, 09:16:01 AM
My 83 Heritage came with a 2.73 peg legger.....
Title: 83 Heritage Tbird rear end.
Post by: Grumbles on March 27, 2009, 07:55:52 PM
So how does somebody make the switch then?
Title: 83 Heritage Tbird rear end.
Post by: 86XR7project on March 27, 2009, 08:02:08 PM
Quote from: Thunder Chicken;264226
It's not a job for the unskilled. Hell, I'm a licensed mechanic and I would balk at doing it...


I think you'd want to go to someone who knew what they were doing.
Title: 83 Heritage Tbird rear end.
Post by: 1BDBIRD on March 28, 2009, 07:26:15 PM
Its easy to put a locker in if you retain stock gears. Simply remove the old carrier and change the ring gear over. (keep track of shims) n put it in and torque it to 90 ft pds. add gear oil and go burn two instead of one!!!!
Title: 83 Heritage Tbird rear end.
Post by: Grumbles on March 30, 2009, 11:04:40 AM
Can I exchange the entire assembly np, or is it more complicated than that?  I want a locker pretty bad :[
Title: 83 Heritage Tbird rear end.
Post by: 86XR7project on March 30, 2009, 11:22:13 AM
If you've never done it I wouldn't attempt. You need precision tools for adjusting backlash and it sounds like its not that easy to do. I HAVE the tools and I won't do it.
Title: 83 Heritage Tbird rear end.
Post by: Thunder Chicken on March 30, 2009, 01:41:46 PM
Quote from: Grumbles;264803
Can I exchange the entire assembly np, or is it more complicated than that?  I want a locker pretty bad :[
If by "exchange the entire assembly" you mean replace the entire rear end, housing and all, then yes, you can do it, and it's not difficult at all. Undo the brake line, unbolt the driveshaft and shocks, drop the rear until you can pull the springs out, then unbolt control arms (if there's a sway bar, remove it), and lower the rear out. Reverse everything to install the new rear.

You'll probably have an easier time finding an 8.8 than you will finding a 7.5 with traction-lock that will bolt in. For 7.5, look at 83-86 Turbo Coupe, 84-86 Cougar XR7, and pre-86 V8 Mustang or Mercury Capri, as these will be most likely to be lockers. You can find lockers in any other 83-88 T-Bird or Cougar, but they're not easy to find.

An 86-93 Mustang 8.8" locker rear will bolt right into your '83 with no modifications required. You can also install an 87-88 Turbo Coupe rear, but this is a disc brake rear and will require some minor modifications to make the disc brakes work (see stickies in this section). The 8.8 is considered an upgrade as it's stronger and has more aftermarket support, but at stock power levels it's a dubious upgrade. Its only advantage is that it will be easier to find a locker that will bolt into a Fox body, as 87-93 5.0 Mustangs are everywhere.
Title: 83 Heritage Tbird rear end.
Post by: Kitz Kat on March 30, 2009, 04:14:15 PM
It would really depend how much you understand a dial indicator.
And be able to change shims to get a pattern on the gear. A install kit for about $40 would be all you need. What year is your car?
I did answer your wanted add.
Title: 83 Heritage Tbird rear end.
Post by: Kitz Kat on March 30, 2009, 04:20:38 PM
I see you have an 83, you can find a stang to fit.