TacoBill

This 'How-To' will cover the installation of the Coast 1-piece aluminum driveshaft.

Tools required
Various metric sockets (10, 12 (12 point), 13, 18mm)
12mm (12 point) ratcheting box end wrench (optional)
12mm (12 point) crows foot extension
Universal joint socket
Socket extensions (various lengths)
Blue Loctite
Torque wrench (up to 76 lb-ft)
Long flat blade screwdriver (or equiv. pry tool)
Brake cleaner (or equiv.)
Straight edge razor blade
Masking tape
Markers (2 different colors)


Estimated install time: 2 to 4 hours


Note: Special instructions added if installing a BMR front safety loop.

Note: Special notes included if you have a MGW shifter and are planning to install a BMR loop.


Installation

1. Jack the vehicle up as high and safe as possible. Always use jack stands!

2. Using a suitable marker (I used paper 'white-out'), index mark the 6 o'clock position of the forward transmission output flange and the rear pinion flange.
Using a different color, mark the orientation of the driveshaft to the 2 flanges (in the event the OEM driveshaft is ever reinstalled).

Note: On the rear pinion flange, two 6 o'clock index marks were made, one near the pinion seal and one on the driveshaft's Constant Velocity (CV) joint.






3. With the transmission in neutral, e-brake off, rotate the driveshaft (or have a helper turn the rear tire) for best access to the CV bolts. Set e-brake (so the bolts can be removed).


4. Using a 10mm socket, remove the (6) CV joint bolts.

Note: After the removal CV joint washers (the long crescent shaped washer that joints 2 bolts), re-install 3 of the bolts in snug, staggered.







5. Using a 12mm (12 point) socket (or ratcheting wrench), remove the 4 driveshaft flange bolts to the transmission output flange.

Note: Release the e-brake and rotate the driveshaft as necessary to gain access to the bolts. Do not forget to set the e-brake.

Note: Don't worry, the driveshaft will stay put even after all 4 bolts are removed.

Note: Save these 4 bolts, they will be re-used.



6. Using a suitable pry tool (a flat blade screwdriver worked fine for me), insert it into the U-joint at the position shown. The driveshaft will compress slightly to allow the driveshaft flange to disconnect from the transmission flange.
Leave it in this disconnected state.

Note: Move back to the pinion flange and remove the 3 bolts from step 4 Note.





7. Place a couple pieces a 2x4's on top of the mid-pipes to keep the driveshaft from falling onto the pipes once the center bearing bracket is loosened.



8. Using a 13mm socket (and universal joint adapter if required), remove the 2 bolts from the center bearing bracket (located about mid-way on the driveshaft).











9. Driveshaft is now completely unbolted from the vehicle and now can be positioned to be removed through the rear in-between the mid-pipes.

Note: After the driveshaft is removed, make sure both spacer washers that were under the center bearing bracket are removed off the body.









Driveshaft comparison



Pinion Angle
With the driveshaft removed, and if your car is lowered, use an angle gauge to determine what your pinion angle is.
With the car positioned at the same angle as it is on the ground (1/2" forward rake for me with the Steeda Ultralite springs), I jacked the rear pumpkin to the desired height in relation to the front, loading the rear suspension.

Front transmission output flange measured at -3.0 degrees.
Rear pinion flange measured -1 degrees.

If I'm correct, my pinion angle is -2 degrees in relation to the front.
I've been told that Ford's spec on the pinion angle is between -2.75 and -3.0 degrees.


10. Preparation for new driveshaft installation
A thorough cleaning must be done on the rear pinion flange prior to the installation of the adapter plate. According to Coast, the adapter is machined to a zero tolerance fit, so to have it mate against the pinion flange without any debris (Loctite, grease, etc.) in-between is absolutely critical!

Clean off any thread locker off the threads from the factory CV joint bolts as well as the driveshaft flange bolts.






Using a plastic scraper and/or single edge razor, carefully scrape off any dried thread locker off from the pinion flange.


Pinion flange should look as clean as this.



10A. Position the Coast adapter plate into the pinion flange and using the six bolts, evenly draw the adapter into the flange using a standard 'star' torque pattern until all 6 bolts are tight (but, not torqued).

Note: Do not put any Loctite on these bolts yet, must be installed dry at this time to avoid any Loctite from dripping in-between the adapter and pinion flange (Yes, it's that critical!).

Note: The pinion flange depth is approx. 0.400" and the adapter step (that get's inserted) is approx. 0.550". So when drawn down and mated, about a 0.150" gap on the adapter will be visible.




Note: To ensure the adapter is fully and evenly seated onto the pinion flange, rig up a magnetic dial indicator (or hold stationary anything non-metallic) and have a helper turn the tires to check for flatness/trueness on the face of the adapter.


10B. Once the adapter plate is fully seated, remove one bolt at a time and apply Loctite on the threads, re-install, and torque to 41 lb-ft.

Note: I used a piece of masking tape to mark each bolt that I Locktited and torqued to avoid any confusion.

All 6 CV joint bolts installed.

Special Section: BMR front safety loop
Whether you need a safety loop is all up to you.
Here's NHRA's take on it..
A driveshaft loop will be required on all cars running 13.99 or quicker and utilizing slicks, except vehicles equipped with street tires running 11.49 or slower.

For those installing a BMR front safety loop, see the installation steps below.
For those not installing a safety loop, skip to step 11.



BMR1. Remove the 2 rear transmission crossmember bolts using an 18mm socket









BMR2. Mount the BMR driveshaft loop mounting crossmember to the transmission crossmember, re-install the factory bolts and torque to 55 lb-ft.







BMR3. Insert the new drive shaft though the BMR loop and let it hang until the 4 bolts on the driveshaft flange to the transmission output flange are installed and torqued complete.
(no picture)


BMR4. Mount the loop portion to the crossmember portion using the supplied bolts and nuts.



BMR5. Position the loop so it's even on both sides of the driveshaft (can use you fingers to check for even gap).
(no picture)


BMR6. Tighten the 2 bolts and ensure the even gap is maintained.





Special Section: MGW Short Throw Shifter
If you have a MGW shifter, the BMR loop will interfere with the adjustable shifter block on the 1-3-5 shifts.

To eliminate this riding condition, you'll need to fabricate a shim that will be placed between the BMR crossmember and the safety loop.

A 0.250" (1/4") shim was fabricated, but the shifter block just barely makes contact with the loop on the 1 shift (3 & 5 do not make contact).

Note: The supplied BMR bolts will be too short with the addition of a shim. Longer bolts will be needed to accommodate the shim and to allow at least 2-3 threads to protrude past the plane of the nut.
I recommend obtaining either 1½" or 1¾" long Grade 8 bolts (BMR supplied bolts are 1" long).

Note: I have the shifter block turned all the way in (then backed out to align the black arrow to the drivers side) at zero turns to give as much clearance to the loop as possible. Throw is a tad longer than what I had at 6 turns, but still feels very good and is still shorter than the stock throw.









Neutral


1st Gear


Note: With the rear suspension unloaded and with the 0.250" shim in place, there is a 0.390" gap between the bottom of the driveshaft and the loop. So this means that I can afford to go with a thicker shim (I'm thinking 0.350" think) to eliminate the 1st gear interference and still have a gap between the loop and driveshaft.
I have not tried this yet, but when I do, I will update this thread.

Edit:
New 0.350" shim is in place along with longer Grade 8 bolts (1 1/2" long) and everything is fine, no riding conditions between the safety loop and MGW shifter block.

Note: To all.. after helping with a few BMR-MGW installs, I recommend going with a 0.380" shim to be on the safe side.


I was able to safely turn the shifter block out to 5 turns too.


11. New driveshaft installation
With the e-brake off, index the 6 o'clock marks you made on the pinion flange and transmission output flange.

Position the new driveshaft up from the rear in-between the mid-pipes and carefully route up to the front.
Place rags over any sharp objects to avoid scratching the new aluminum driveshaft.

Note: If you accidentally ding any part of the driveshaft, STOP your installation and contact Coast at 800-533-8087 for advisement.
Let me put it this way, my first driveshaft arrived with a small, smooth dent (thanks to UPS) and Coast flat out rejected it for use.

Mate up both ends of the driveshaft's U-joints against the rear pinion adapter plate and the forward transmission output flange.

Rotate the driveshaft if necessary to pick up the previously used 4 bolt holes in the transmission output flange, and make sure the 6 o'clock markings didn't move while rotating the driveshaft.

Once everything is in position, Loctite each bolt and snug down tight. Using an 'X' pattern, torque the bolts to the following;
Driveshaft to transmission output flange: 76 lb-ft
Driveshaft to pinion adapter plate: 41 lb-ft

Note: A standard socket - universal joint adapter - ratchet combo will not fit squarely on the U-joint bolts. Correctly torquing these bolts will be difficult without a 12 point Crow's Foot extension (or equiv.).
If you choose to use an extension, use the following formula to set your correct torque value.

(T x L) / (L + E) = Adjusted torque value (what you set on your torque wrench)
T= target torque value
L= length of torque wrench in inches (end of handle to center of socket)
E= length of extension in inches (center of socket to center of bolt)

If using a 1" Crow's Foot extension on the front U-joint bolts, here's the way the formula works out.
(76 x 12" torque wrench) / (12" torque wrench + 1" extension) = 70.15 lb-in torque. This is what you would set the torque wrench to.










Installation complete!








Note: According to Coast's written instructions as well as a few online sources, there seems to be a clearance issue between the e-brake cable bracket and the driveshaft. Instructions will have you re-drill the bracket bolt hole and move it 1.5" away from the driveshaft tunnel.

On my 2006, I don't see any bolt attaching the bracket to the tunnel. Instead, it looks to be spot welded on or something, nor do I see no clearance issues between these two. With the rear suspension unloaded, there's a good amount of clearance between the bracket and cable to the driveshaft so I don't see a need to relocate this bracket.


*Edit*
I think I know which bracket they're talking about now. It's a small support clip/bracket that supports the e-brake cable that goes to the passenger side brake. On an aggressively lowered car, I can possibly see some clearance issues to the bolt head of that clip/bracket if not re-located.

See pic below for reference.












New update:
Took the car out for a short test drive mainly to check for anything wierd (vibrations, etc.). Couldn't open her up on the highway because of traffic, but I went to my secret proving grounds and got up to 80 and no vibrations!

MELLOWYELLOW06

Will you help me install one in mine, Sir Tacobill?

Humbly yours,

Mellowyellow06

BigDave

Great write-up, as usual. Your photography is always outstanding. What camera do you use?

I think the best thing about it is the fact that your son is involved in your car hobby. My 22 year-old couldn't change a valve stem cap and my 18 year-old is interested, but lives in Oklahoma and I rarely see him. I have 4 more boys 9, 3, and the 10-month twins to hopefully addict to cars (especially Mustangs!). We'll see...

EskimoPie

Awesome post as always TB... now what are your driving impressions with the new DS?

moosestang

Am I the only one that drives my car everyday? I didn't see one spot of rust on anything under your car![:@]

I know you weren't under that car with just that craftsman floor jack supporting it. Please tell me there were some jackstands somewhere out of site.

06GT4RAD

Great Write up as usual Bill.

Moose I am certain Bill is using Jack Stands since he makes it a point in his directions. As for the car being clean. Mine may be as clean as Bill's underneath but my guess is he wiped things down while he was under there so he may have me beat. I know i do not drive the car during the rainy season and currently the car has not been driven in about 3 weeks due to all sort of road construction around my house. The main Hwy is being repaved and until it gets done and all the loose asphalt has gone away the car will stay in the garage.

Richard

MIKE562

Whenever I have a question regarding our Mustangs, I ask myself this: WWTBD? (What would Taco Bill Do?) You rock [sm=icon_rock.gif] Excellent write up

marcuskeeler

Great install write up as always Bill. Would like to know if there is more/less driveline vibration ?

Pics were taken with a Canon PowerShot SD550 by the way,

NickSezz

It looks like you can eat off of the under side of your car. I am in awe everytime I see how clean and perfect everything is. Your son is going to have a great thing passed on to him.

This is a great thing you do for everyone on here and I bet you enjoy making these wright ups just as much as we do reading them.

TacoBill

Thanks everyone for the kudos, I really appreciate it!


Umm.. it was a once in a lifetime experience. Let mereiterate, once. [8D]


Nothing yet. My test drive has been limited to backing it out from the garage and re-parking it!
Need to fabricate a thicker shim and get longer bolts (for the BMR loop) before I go on a 'fun' test.


Not my daily, hasn't seen rain (yet). Makes working under the car pleasurable (to a point [&:]).

C'mon Moose, you know be better than that. I took these pics, but didn't post them in the original write-up.







See my response to EskimoPie's question.
When I do add the shim and bolts, look for my SOTP meter feedback here. [8D]

Correct on the SD550. Small enough to snake in some pretty tight spots.