One Piece Drive Shaft Installation
written by Octavio Diaz
Pictures and installation instructions by Paul Pfau


The driveshaft on the stock 2005-2007 S197 Mustang is a two piece articulated design.  It weighs in at over 45lbs.  This drive shaft has a hanger bearing that moves up and down violently under hard acceleration.

A one piece drive is lighter thus allowing it to rotate faster and gives you more horsepower.  Reducing the total rotational mass of the driveline allows the engine to rev up faster and provide more torque to the wheels. Many manufacturers are quoting a gain of 20rwhp and 20ft.lbs. of torque along with dropping 1/4 mile times approx 2 tenths of a second.   When shopping for a drive shaft, keep in mind that driveshaft isn't the place to try to save a few dollars; unless you know it comes from a driveshaft builder that specializes in driveshafts for high horsepower applications. Any money you save today will be spent 3 or 4 times over if the joints break and the drive shaft cuts through your floor plan and underbody.  A driveshaft turning 5k RPMs will do lots of damage to a car if it breaks.  This is where carbon fiber driveshafts provide some advantage.  They are stronger, can handle more horsepower and if they brake, they will splinter into thousands of small pieces and not damage your car.
   

Aluminum driveshafts offer a more cost effective solution and in some cases are lighter then even carbon fiber.  Aside from the weight savings, one other thing to keep in mind is the diameter of the drive shaft it self.  It has been reported that some of the 4" driveshafts have experienced clearance problems for street application in vehicles that have been lowered.  Also, the emergency brake cable will need to be moved 1.5" to the left.  To do this, simply drill a new hole and remount the bracket.  The 4" drive shaft will interfere with the Saleen short shift adaptor so if you are planning on using one of these, you will need to remove the short shift adaptor.  To verify you won't have any problems, call your vendor and discuss your application before you order.

Finally, the drive shafts are rated at a maximum HP.  Make sure that the driveshaft you choose will be able to handle all the power your car can throw at them now and later after you add more mods (like a supercharger or turbo).

Aftermarket driveshafts for the S197 mustang are available from a number of different vendors and range in price from about $700- over $1000 for a carbon fiber design.  The following list is not complete but it gives you some idea of the different options available:
Spyder - 4" GT Aluminum - 16.5 lbs
Coast - 4" GT Aluminum - 17 lbS
Power House Automotive - GT 4" Aluminum - PHA-DS05 - 19 Lbs    
BMR Fabrication - GT 3.7 Carbon fiber - DS005 - 20.7 Lbs
Denny's Drive Shaft - GT 3" Aluminum - FM200567NR  - 23Lbs
Lethal Performance - GT 3.5" Aluminum - DSS-FDSH4 -

The one piece drive shaft will connect to the pinion gear at a different angle then the stock driveshaft.  To compensate for this the adjustable LCAs are recommended.  The Lower Control Arms (LCA) will need to be shortened to correct the pinion angle.  Failure to do so will result in vibration at various speeds.  The OEM pnion angle is between -2.7 and -3.

Finally, for higher HP applications, a driveshaft loop is highly recommended and required for cars running faster then 11.49 seconds in the quarter mile or any car that is using slicks.

The following procedure describes how to replace the driveshaft with an aftermarket one piece driveshaft:

Toools Required:
  • Jack and jack stands
  • Pinion angle finder
  • Adjustable Lower Control Arms
  • 3/8 ratchet
  • Torque wrench
  • 12mm socket (12 point)
  • 13mm socket
  • 14 mm socket
  • 5/16" hex bit socket (3/8 drive)
  • Wheel bearing and CV joint grease
  • Ratchet extensions

Let's get started.  Obviously the first step is to jack up the car.  You will need to raise both the front and the rear as much as you can with jack stands. After the car is safely resting on jack stands, place the car in neutral.  This will make it easier to change the driveshaft by allowing rotation of the shaft and yokes.  If you are planning on using ramps at all, use them in the front.  The rear wheels of the car must be able to turn freely so that you can rotate the rear yoke.


The bolts that hold the CV joint to the pinion are 10mm and ford put an ample amount of locktite on them.   They weren't all that tight as far as torqued, but they were tight almost all the way out of the hole.  Here's a tip that the service manual instructions fail to mention.  Leave two bolts in the rear, finger tight.  This is to keep the driveshaft from moving when removing the transmission mounting bolts.

Next you can remove the 4 12 point (12mm) bolts that hold the driveshaft to the transmission.

Your going to need a breaker bar of some kind to put on your ratchet.  I used the closed end of a 1 1/8 inch wrench, worked like a charm.  Be sure to mark the tranny flange and U joint flange incase you ever want/need to put the stocker back in, you want to put it in the same holes.  Once you remove all the bolts you'll need to pry the flange off the tranny.  Don't just pry at any spot.  In the picture above you want to put the  pry tool in the U shaped spot to the right of the bottom bolt.  If you think you can use your tire iron as a pry bar you are sadly mistaken.  I ended up using a large flat blade screw driver and it came off easier than I expected.

Now is the time to find something to lay between the exhaust pipes to support the driveshaft. Actually you should allready have done that.  I used a couple of pieces of wood.  you can go back now and remove the two bolts you left in the rear mount  Now you need to remove the carrier bearing bracket bolts.


The bolts are 13mm but a 1/2 socket will also work. You'll need some extensions on the socket to get at these bolts.  Be sure to pop off the aluminum spacers between the body and carrier bracket.

One of mine came off by itself, but the other was stuck there.  I used a screw driver to pop it off.  You don't want them falling off down the road.

You'll need to slide the driveshaft out the back.  It would help to have another person, but I did it by myself.  Now to put the new driveshaft in.

First you need to install the aluminum adapter to the pinion flange using the 6 allen head bolts (hex bolts) supplied.  I had to go to discount auto to buy a 5/16th inch, 3/8 inch drive hex bit socket.  It cost $5.  Use loctite on these bolts!


Once again I had to crawl out from under the car to release the E-brake in order to turn the pinion flange, to access all the bolts.  The E-brake worked fine to hold the rear end because Ford specs are 41 ft lbs for these bolts.  Be sure you have the car high enough or a short enough torque wrench.  There is very little room to torque these bolts due to the exhaust. 

With the drive shaft removed, you will need to adjust your pinion angle by shortening the length of the Lower Controla Arms.  If you don't have adjustable LCAs, you can continue with the installation but take it easy because the car will vibrate unless the pinion angle is corrected.  As previously stated, the OEM pnion angle is between -2.7 and -3.

The following article describes how to adjust the LCAs to correct the pinion angle:

http://www.cherod.com/mustang/HowTo/LCA%20_adj.htm

Now is the time to put the new shaft into place.  I recommend finding something to lay across the H pipe that is tall enough to put the driveshaft up to the height of the tranny flange.

You need to attach the rear first using the 4, 14mm bolts and lock washers supplied.  I went ahead and used locktite here to, but it's probably redundant.  The manufacturer did not specify how tight to torque these but Ford calls for 41 ft. lbs in its specifications. Again,  the driveshaft  will need to be rotated to get to all the bolts. 

With the rear attached slide the front up to the transmission mount and install the original 12 point 12mm bolts you removed.  Use loctite on these bolts!  Ford specs say 76 ft lbs.  Be sure the rear tires are resting on something or your driveshaft will spin when torqueing these.

The slip joint on the driveshaft will need to greased after the install.  I used Valvoline full synthetic wheel bearing and CV joint grease.  The hardest part of this install is adjusting the pinion angle. Total install time should be between 3-4 hours provided you have all the tools and are properly prepared.  

When you're all done, lower the car and enjoy your new driveshaft.