wabalaba

This job took me a long time and I hit many snags, so I wrote up this guide to hopefully help someone else avoid my pitfalls!
How to change your clutch in a 2005-2010 Mustang 4.0L with the T5 transmission.

In hindsight:
-->This job is long, but it is not actually technically complicated. If you have a reasonable set of tools, you might only need to get a few odd sockets and a transmission jack (you can make-do without it).
-->This job TAKES A LONG TIME the first time. Expect to find surprises. Expect Rock Auto to do something silly like send you a box of broken **** instead of good new clutch parts, and to have to ship it back (Grr!)
-->Be careful swapping seals and be really careful with the rusted, seized exhaust bolts.
--> Overall, this is absolutely a job worth doing if time is not a concern. If you can afford to go slow and do everything right (like if it's not your only car) you'll save a huge amount of money. If you need to rush, well, you won't have fun.


0. A few things you need that you might not have on hand

• 12-point, 12mm socket for driveshaft bolts
• 12mm e-torx socket for flywheel bolts
• New pressure-plate and flywheel bolts (see part 6)
• Three-point puller tool
• Four feet or so of 1/2" socket extensions.
• Transmission jack (or redneck-engineering equivalent)
• High-temperature gas torch (capable of heating metal to red-hot)
• Barely optional: a "creeper" roller cart to lie on
• Optional: a tool and die set with M10x1.5 die to clean up the exhaust stud threads
• Optional: some M10x1.5 nuts to replace rusty ones on the exhaust
• Optional: rear crankshaft seal, transmission output shaft seal, differential pinion seal
• Optional: rear crankshaft seal install tool
• Optional: a very good and willing friend

1. Set-up and Clutch Master Cylinder (CMC)
https://iihs.net/fsm/?d=272&f=Clutch...20Cylinder.pdf

• Get the car safely up on four tall jackstands. Despite all the warnings, you can safely lift by the differential if you are careful not to damage the differential cover.
• I had to go up to the maximum height my jackstands would allow. Use some wood blocks also for extra insurance. Can't drive your mustang if yer dead.
• Disconnect the battery (8mm)
• To replace the clutch master you'll need to climb under the dash and detatch the brake/clutch pedal assembly from the firewall in order to make enough room to fit an allen key around the side of the assembly to unbolt the CMC. It might be possible without unbolting the assembly but I could not manage to do it.
• The pedal assembly is mounted on four studs by 13mm nuts. You'll need a deep socket and probably a short extension to make it easier to work in the tight space.
• Mind the plastic brake and clutch switches which turn clockwise to release. Disconnect the pedals from their pushrods.
• CAREFULLY wiggle the assembly off the four mounting bolts (I somehow damaged my probably-original brake booster by hitting that pushrod and got to replace the booster as a bonus job!)
• Two allen-keys bolts on the left side hold the CMC to the assembly. Once it's free, remove the assembly from the car to make room.
• In replacing the CMC, you'll need to disconnect the metal hydraulic line that runs to the transmission and the rubberized hose that runs to the brake fluid reservoir. I'm not sure how to do this without spilling some brake fluid. I attacked this by using lots of rags and paper towel. Brake fluid eats paint, so flush with water if you spill on paint. If you can find a way to cap off the hoses and reservoir, you'll be laughing.
• TIP: there is a soft foam/rubber seal that seats against the firewall and through which the lines from the CMC pass. It does have a correct orientation! There's a part that sticks out in the way of the CMC mounting bolts if you install it backward. I installed it backward and wasn't willing to start over when I found out, so be aware that you can just make-it-work if you put it on backward.
• TIP: you can remove the two screws holding the A/C suction accumulator in place (it's the cylinder-looking thing left of the brake master cylinder, behind the strut tower). Once this is loose, you can move it a bit to gain extra room to fit your hands in.
• Reassembly is straightforward, but a pain in the cramped spaces.
• NOTE: you might want to block fluid flow into the new CMC since you're going to have the hydraulic line disconnected at the transmission. You could achieve this by draining the reservoir below the level of the clutch hose nipple before installing the new hose.

2. Exhaust
https://iihs.net/fsm/?d=306

• My car has a dual exhaust, but most have a single. In either case, you unbolt a few clamps along the length and then slip the pipes out of their hangers using the wiggle room granted by the loosened clamps. I found that I needed to unbolt at the centre of the car, wiggle the long pipes loose there, and then pull it forward to get the mufflers out of their hangers.
• Disconnect and unscrew the O2 sensors. Be careful because they have very soft threads. My two upstream ones stripped themselves as I unscrewed them.
• TIP: inspect the connector on the O2 sensor. If you try to fit a 22mm box-end wrench over it, you'll see a little plastic bit that blocks you. You can snip this off without any problems. It doesn't affect how the connector clips on. This will allow you to slip a wrench over the nut on the sensor. I don't think there's room to use one of those O2-sensor sockets.
• The upsteam sensors have a green connector, downstream have blue.
• TIP: it is probably a good idea to run the car until the pipes are just getting hot, and then try to remove the sensors (I didn't do this).
• TIP: if your O2 sensors strip themselves like mine did, get a 10.9, M18x1.5x100 bolt and hacksaw two grooves along its length to make a cheap thread chaser for the exhaust bungs. Or find a deal on an "actual" O2 sensor thread chaser.
• Note that the nuts holding the y-pipe to the headers will almost certainly be seized like it's God's Will for them never to come off. Use an oxy-acetylene torch to (carefully!) heat the nuts until they glow then work them off. The studs are M10x1.5, in case you want new nuts. I believe all the exhaust system nuts were 15mm but you'll have to check your car. A few of mine were trashed so now whatever I had lying around is on the car!
• If you mangle the studs trying to remove the nuts, try to spin a die over them to clean up the threads and use two nuts during reinstall to spread out the stress on the crappy threads. Might be enough to make the car driveable until you can get the stud replaced.

2. Driveshaft
https://iihs.net/fsm/?d=78

• Four bolts hold the driveshaft at each end. These require a special 12mm, 12-point socket because Ford hates me. Index the driveshaft to the flanges on the differential and transmission with paint or a few scratches so that you can re-mount it in exactly the same orientation to prevent any imbalances that might cause vibrations. Be careful: the driveshaft will likely need gentle prying to get it loose and it is fairly heavy! Don't let it fall!
• It helps to have a friend here to put the car into neutral while you rotate the shaft to get access to different bolts, and then into gear while you reef on the bolts to unseat them.
• Do not hammer on the driveshaft itself; it is very precisely balanced. Pry gently where the U-joint meets the flange, using the square-shaped cut-out in the U-joint mounting plate. Lightly hitting the U-joint with a rubber mallet seems to be fine also.
• Check the condition of your U-joints by seeing if there's any play. But removing the driveshaft is fairly easy, so if time is an issue, just replace them later.
• If working alone, get one end of the driveshaft loose and then rest it on some wood blocks while you work on the other end. Try not to drag the shaft on the floor more than needed.
• Check the underside of the differential and the tailhousing of the transmission for signs that you have a leaky seal in either place.

3. Pinion seal
https://iihs.net/fsm/?d=87&f=Drive%2...ion%20Seal.pdf

• If you need to change this seal, there's a very particular process required. If not, skip ahead.
• The official process requires one of those old-school, bending-bar type torque wrenches that can read in inch-pounds.
• I didn't have that, so I followed the method in these two videos. This method is simple and seems fairly safe but it is NOT the "correct" method. Be careful! (So far, it seems to have worked for me)
  • You Tube
  • You Tube
• You will need a 1 1/16" socket to remove the pinion nut and a three-point puller to extract the pinion flange.
• TIP: you don't need to drain the rear end for this, but some fluid will leak out so you'll at least need to top it off after.
• TIP: if you decide to drain the rear end, you can get a proper gasket for the differential cover instead of using messy silicone. It's not spec'd for our cars, but all the 7.5" rear ends are the same, so you can get a gasket meant for an '80s Ranger or something. Totally optional.

4. Transmission rear seal and input shaft seal
https://iihs.net/fsm/?d=273

• I haven't done the rear seal yet because I ran out of time, but I need to do it. This is easier than the pinion seal because there's no matter of preloading bearings. Note that the nut is a single-use but some people online say you can re-use it if you seal the threads with silicone.
• I think this nut is also 1 1/16", or it is 1 1/4".
• You will also need a three-point puller to remove the flange.
• Replacing the input shaft is another thing you could do now, but I did not attempt since mine isn't leaking and it's not so simple. I haven't figured out exactly how to do it.
  • If you want to do some research, instructions with much better images for dismantling the similar, older style T5 transmissions are here: https://www.tremec.com/anexos/TRSM-T5-0510-R1_173.pdf.

5. Removing the Transmission
https://iihs.net/fsm/?d=281&f=Transmission.pdf

• NOTE: in theory you need a transmission jack for this. I got by with a floor jack and some ratchet straps but it kind of sucked and made reinstallation a pain. If you can get a proper transmission jack, you will not regret it. If you can weld, there are tutorials on youtube detailing how to adapt a floor jack into a trans jack (I did not do this).
• Disconnect the starter. There are two wires bolted to it. I believe each is a 10mm or maybe 8mm nut. There are only two bolts mounting the starter to the bellhousing. I believe these are 10mm also.
• There are two electrical connections to the transmission (speed sensor and reverse lamp switch). Disconnect them and get the harness out of the way. Note that part of the harness it attached to a bracket held on by one of the bellhousing bolts.
• Disconnect the clutch hydraulic line by prying out the staple-shaped pin in the connector (keep it!) and popping the connection off. All the fluid in the line will now drain out, so be ready.
• TIP: The transmission cannot be separated from the bellhousing! You must remove it all as one assembly.
• TIP: You don't have to drain the transmission, but it's certainly easier to refill it while it is on the ground, so consider doing a fluid change while you're here.
• Support the transmission with a jack. Support the engine at the oil pan with another jack or else it will tip backward when you try to pull the transmission. Spread the weight of the engine with a piece of wood so you don't damage the pan.
• The transmission mount at the rear has four large bolts (19mm?) and a smaller central bolt (13mm). Check the rubber here to see if this needs replacing.
• Above the transmission are the rods connecting the shifter to the transmission. These nuts are 10mm and the bolt is 13mm.
• TIP: this is a good time to consider replacing the rubber bushings in this linkage assembly. They are the same in the GT and the V6, so don't worry that you can't find any listed for the V6.
• There are 8 bolts holding the bellhousing to the engine. I am pretty sure these are 13mm. The top ones can be a real pain to get to. Try using four feet of socket wrench extensions and feeding that in from behind, over top of the transmission.
• TIP: The bellhousing bolts are not all the same length. Keep them organized.
• Once the bolts are out and you're sure everything else is disconnected, gently begin to wiggle and pry the transmission case back. Be mindful of the two locating dowels (at roughly 3 o'clock and 9 o'clock around the bellhousing) This is not the time for violence, but it may need some convincing to come loose. Mine took a fair amount of convincing and it finally came loose with a bang!
• TIP: Wear an N95 dust mask when working in this area. Clutch dust contains microscopic shards of asbestos. Don't be stubborn about this. Spray down the bellhousing with water and consider washing it out with brake cleaner.
• Roll the transmission back until the input shaft is clear of the pressure plate, then carefully lower the transmission out of the way.
• The clutch slave cylinder mounts with two 10mm bolts.

6. Removing the clutch parts
https://iihs.net/fsm/?d=268&f=Clutch...20-%204.0L.pdf
https://iihs.net/fsm/?d=155&f=Flywheel.pdf

• Ford thinks the pressure plate bolts are made of vibranium and will charge you an absurd amount of money for new ones. Officially, they should be replaced. If you're doing an OEM replacement, grade 10.9, M8x1.25x20mm bolts will work as replacement. Note the shape of the head: https://www.tascaparts.com/oem-parts...lt-w709479s439. My car did not have the OEM bolts, so I don't know what size they are.
• The pressure plate may need a bit of gentle prying but will come loose easily. The clutch disc will fall out as you pull the pressure plate away. I used a crowbar wedged into the ring gear of the flywheel to hold things steady while I unscrewed these bolts (and the flywheel bolts).
• The flywheel bolts (there are 8 of them) require a special "e-torx" type socket because it pleases Ford to be difficult. These are 12mm. The flywheel is pretty darned hefty; don't let it fall on you!
• NOTE: the factory flywheel has a raised rim going around the edge of the working surface, where the pressure plate bolts to. Some aftermarket flywheels are flat right across the face. It is a good idea to get this far before ordering replacement clutch parts in case (like me) you find out too late that your flywheel isn't stock and the pressure plate you ordered won't fit. The LUK "Repset" #07202 comes with a new flywheel of the flat kind, along with pressure plate, friction disc, pilot bearing, and slave cylinder. I chose that the second time, but I bought a pilot bearing direct from their parent company to be sure I got a good one.
• NOTE: Ford says their stock flywheels cannot be resurfaced. If your car is an '05 or an '06, this is not true; you just need to go to a good machine shop that can handle the raised lip. Sometime either during or after 2007, Ford switched to a dual-mass flywheel that should not be reused because something inside it wears out. It's worth switching to a single-mass flywheel to save money and get more use out of it. There's no major difference in driving feel.
• TIP: I have read repeatedly that people who chose aftermarket lightweight flywheels regretted it. This engine seems to like a steel flywheel. Do your research, at least, before buying.
• You need to keep the weird, thin metal plate that's behind the flywheel, so don't damage it.

7. Rear crankshaft seal
https://iihs.net/fsm/?d=155&f=Cranks...ear%20Seal.pdf

• The 4.0L engines are known for being tricky with these seals. While it's good practice to replace this seal while you're here, I tried my best to do it carefully and still got burned by a huge oil leak when I reassembled the car and test-drove it. I don't have time to do the whole job again, so now I have to pay about $750 Canadian to have the seal done again. If yours isn't leaking you might consider leaving it alone. Even if it starts a small leak down the road, it's better than a huge leak.
• If you do decide to replace the seal, be extremely careful not to gouge the crank while pulling it. Consider getting the installation tool, or using a bolt and a wide washer to pull the seal in evenly. I did it the old-school way by hammering on a piece of exhaust pipe and I think I paid the price!

8. Installing the clutch parts
https://iihs.net/fsm/?d=265

• I used threadlocker on the flywheel, pressure plate, and driveshaft bolts. I don't know if it's necessary, but it's cheap insurance.
• Use a socket just a hair smaller than the pilot bearing to gently hammer the bearing into the flywheel. Lightly grease the outside of the bearing before installing. You want the bearing flush (see the old flywheel as comparison).
• Use the dowels to hold the thin metal spacer plate in place.
• The flywheel bolts aren't listed as being torque-to-yield in the manual, but they are not super expensive from Ford and, again, it's cheap insurance against getting your ankles cut off by an escaping flywheel. Thoroughly clean the flywheel working surface with brake cleaner to get any oils off it and mount it with a bolt. The correct torque is done in two stages: first stage is to get all the bolts to 10lb-ft, the second is to torque them all to 52lb-ft. Follow the pattern shown here: https://iihs.net/fsm/?d=155&f=Flywheel.pdf.
• TIP: you need to lubricate the splines of the input shaft with high-temp grease (should be a little packet included with your parts). The friction disc can be used to evenly smear the grease down the length of the splines (don't contaminate the friction material though!)
• Clean the working surface of the new pressure plate with brake cleaner. Put the friction disc in place (the side with the damper springs faces the transmission; it should be labeled) and lift the pressure plate into position. Hang it there with one bolt.
• Use the clutch alignment tool that comes with your clutch parts to align the friction disc with the pilot bearing. When you are sure things are good and centred, install the other pressure plate bolts and go around tightening each a little at a time to bring the plate down evenly. Torque them to 26 lb-ft. You can now pull out the alignment tool.
• You've now installed the new clutch parts!

9. Reinstalling the transmission
https://iihs.net/fsm/?d=281&f=Transmission.pdf

• Scrape off the rust and crud from the mounting surfaces of the bellhousing and engine block (and that metal plate)
• You will need to get the engine and transmission exactly aligned in order to reinsert the input shaft into the pilot bearing and pull the bellhousing flush with the block. Expect this process to take a while and be frustrating.
• DO NOT FORCE THE TRANSMISSION INTO PLACE. If it won't go, find out why.
• The clutch hydraulic line should be connected to the slave cylinder before you reattach the transmission. The staple-shaped clip can only go in from one side (the side away from the transmission; there's a cut-out) and it needs a bit of force.
• Work the transmission in, constantly checking the motor/trans angle. Adjust each very carefully as needed. Be mindful you don't crush the clutch hydraulic line connection against the body.
• TIP: lubricate the locating dowels with grease or anti-seize.
• TIP: put the transmission in gear and turn the output shaft flange to get the input shaft splines to align with the friction disc ones.
• TIP: if you're close but still having trouble, spin in a couple of the bellhousing bolts just enough to act as stops to keep the transmission close to centred while you wiggle.
• TIP: move around and keep checking alignment from different angles. Be very careful to not pinch the wiring harness with the top of the bellhousing!
• When you finally get it installed, reinstall the bellhousing bolts and torque them to 33lb-ft. This will be tough to do, given the tight spaces. You might end up approximating 33lb-ft by hand.
• NOTE: remember that wiring-harness bracket which is held by one of these bellhousing bolts.
• Reinstall the nuts/bolt of the shifter linkage. Torque these to 18 lb-ft. Mind that you have the transmission in neutral while you do this. It may take some wiggling/convincing to get the longer shaft aligned and the bolt re-inserted.
• Reinstall the transmission mounts; the four big ones get 62 lb-ft, per the official Ford manual (my Haynes manual said 85! Now I hope I didn't damage those threads! I knew that sounded iffy...).
• Remove the jacks under the engine and transmission.
• You've now reinstalled the transmission!

10. Reinstalling the driveshaft
https://iihs.net/fsm/?d=78

• Clean the flange faces with a wire brush and some brake cleaner. As said above, be sure to reinstall the driveshaft in the same orientation relative to each flange as it was before you uninstalled.
• As with the uninstall, the driveshaft will have to be rotated, locked, then rotated again as you try to tighten the eight bolts to 76 lb-ft.
• Clean the old threadlocker off the bolts and apply new before reinstalling (or buy new bolts).
• Congrats! The whole drivetrain is back together!

11. Reinstalling the exhaust (mine isn't the single-pipe, so your mileage may vary with these instructions)
https://iihs.net/fsm/?d=306

• Start with the y-pipe (or equivalent). Slide the hangers into place and get the front end lined up on the exhaust studs. I had some trouble with a persistent leak here after install, so line the pipes up well and get 'em good and tight. Consider high-temp antiseize here to save someone else a bit of pain in the future.
• Put the long pipe(s) over the axle first, then slide on the muffler(s). Now, hang the mufflers and you'll have just enough wiggle room at the centre of the car to get the long pipe(s) into the clamp there. Tighten everything down.
• You're almost done now! Lower the car off the jackstands!

12. Bleeding the clutch hydraulics
https://iihs.net/fsm/?d=263&f=Clutch...20Bleeding.pdf

• The official process involves a vacuum bleeder but you do not need one.
• To bleed the clutch without a vacuum, simply top off the reservoir and start pumping the pedal. Pump and pump and pump and pump. It will take ten minutes or more of constant pumping but the pedal will begin to firm up. Pump until it feels normal again.Your knees will be sore but it's free.
• Once the pedal is firm, you can test whether the system is bled enough by starting the car (IN NEUTRAL!) and trying to put it into gear. If you can shift in and out of each gear without trouble, then you're good to go. Be careful that you don't send yourself rolling into the garage wall.
• TIP: I have read people's opinions on forums and some think that jacking up just the driver's front corner of the car helps speed this process up. This makes sense as it would tip the slave cylinder hydraulic line up a bit.
• TIP: I have also read a few people's thoughts that it helps to push the pedal down slowly and release it more quickly. I can't say from my experience whether that worked or not. I tried a variety of rhythms.
• TIP: this process will not use much brake fluid at all, so don't think that your pumping isn't working just because the fluid level doesn't change.
• TIP: listen very carefully and you'll hear when the slave cylinder begins to actuate.
• TIP: there actually is a bleed valve on some of the early cars. It's right on the connector to the transmission. It would be difficult to use in that tight space, but it might work well to save time. I don't know.
• The system will continue to self-bleed any remaining tiny bubbles as you drive it around. I wish brakes would do that too!
• You've done it! You replaced your clutch! Wash yer hands and purchase a cold beverage with some of the money you saved.