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8.8" Traction Lock rear Installation

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8.8" Traction Lock rear installation
Pictures: 88 T-bird Sport

A mustang rear will fit...

     There have been many people that say a mustang rear won't fit into '83-'88 T-Birds/Cougars.  It has been said that in order to bolt an 8.8" posi-rear directly into these cars, you would have to use a T-Bird Turbo Coupe rear and change the master cylinder.  This isn't the case as I have discovered through experimentation. 
 
     Earlier this month(10/10/04) I tackled the job of installing the Mustang 8.8" rear into my T-bird.  I took my time and spread the job out through the weekend.  The task can be completed by anyone with a fair amount of automotive knowledge, simple hand tools and a weekend's worth of time.  For this task, you will need a 1/2" drive breaker bar, 1/2" drive ratchet, 3-6"(1/2" drive) long extension, 12mm 12-point socket, 8-10-11mm line-wrenches(or combos if your careful), 18mm socket(1/2" drive), 18mm combo wrench, and a metric/standard socket set helps(3/8" drive).
 
     I began by loosening the lug nuts on the rear wheels.  I then jacked up the back of the car (under the center section of the rear, not the body) until I could fit a short pair of jack-stands under the rear control arms.  By placing the jack-stands under the rear control arms (directly under coil springs) you eliminate having to compress and remove the rear coil springs.  At that point, I blocked off the front wheels so the car wouldn't try to roll away on me.  Next, I disconnected the emergency brake cables.  In order to disengage the e-brake cables, you need to pull the rear wheels and drums off so you can access the rear brakes for disassembly.  After that, you will need to disconnect the rear brake hose where it meets the brake distribution block (mounted on the driver side of the center section, 11mm banjo bolt).  I recommend buying new copper washers for the line before reassembly.
 
     You can then proceed to disconnect the driveshaft(12mm 12-point bolts).  After the driveshaft has been unbolted from the rear differential, you can proceed to remove the lower shock bolts.  After the lower shock bolts have been removed, it's time to loosen the upper and lower control arm bolts(where they meet the axle, not the body), but do not remove them at this time.  Place a jack under the center section of the rear and remove the bolts for the upper control arms(leaving them attached to the body).  CAUTION: Once the upper control arm bolts are removed, the rear will roll forward, and the pinion will drop to the ground as it rotates forward.  Make sure you have someone help support the rear while you are removing the lower control arm bolts for the opposite side.  Once the lower control arm to axle bolts are out you and your helper can carefully rest the rear on the ground.  Depending on how high the rear of your car is sitting you may be able to roll it out towards the back of the car...if the gas tank is too low to the ground, you can manipulate it out one side or the other.

     After the old rear is out, you will need to swap over the steel brake lines w/distribution block.  If your lines are moderately rusted, I suggest you skip the next step and buy new lines and bend them to fit.  If the lines are in decent condition, you will need to re-bend them to fit over the larger center section of the 8.8" rear.  I don't know if it's the same for these cars with 9" brakes, but I know that if you have 10" brakes on your T-Bird/Cougar, your brake lines will angle out slightly because the wheel cylinders have an angled inlet and you will need to straighten this section out.  CAUTION: while re-bending steel brake lines be careful not to kink them.
 
     Once you have the brake lines installed, you can slide the new 8.8" rear under the car and prepare to hang it from the control arms.  NOTE:  if you have 10" drums on your car, you will need to buy 9" drums for the Mustang rear.  These cars came with 9" or 10" rear drums depending on options.  Check drum sizes before you begin the project.  Getting the new rear hung can be tricky if you do it by yourself like I did.  I recommend having someone assist you in hanging the new rear.  Lift the rear and place it on top of the lower control arms with the lower control arms partially in the brackets on the rear.  This can get tricky too, it sometimes take a little patience and a little tugging of the rear to get the lower control arms into the brackets on the axle.
 
     You can then proceed to put the upper control arm bolts in (but leave them loose) and then the lower control arm bolts (leaving them loose also).  Re-install the lower shock bolts and tighten them with a ratchet, making sure that they're just about as tight as you can get them with the ratchet.  Then use a jack to lift the center section of the rear again, until the car is just barely off the jack-stands.  At this point you can proceed to tighten the control arm bolts with a breaker bar to assure they are tight.  By using this method, it loads the rear suspension and assures that nothing binds up after you drop the car back down.
 
     After this, installation is pretty much the reverse of removal.  Just make sure that you add the proper posi fluid additives and use something in the range of 75W-90 gear lube.  Changing the fluid and differential gasket is something very easily achieved while the new rear is still out of the car. 
 
     After everything is tightened and reconnected, you're ready to test it out.  I drove mine for about 10 miles to make sure there were no noises coming from the rear.  After that, I power-braked the living hell out of my car on a crowned road...and I can say that it sure as hell is fun to go side-ways while stationary.
 
NOTE:  If you're wheels look like they sit further inside the wheel wells, it's because they do.  The '87-'93 Mustang rear axle is appoximately 2.5" narrower than the 7.5" T-bird/Cougar rear.  This will also allow you to use 275/50R15 tires with no clearance issues(unless you have quad shocks).

Disclaimer: Not all safety aspects are covered in this article, work at your own risk.  Make sure to use proper safety equipment and refer to a repair manual for proper torque specifications where needed.