When it comes to transmissions, most of us prefer a stick. Yes, the newest Mustang automatic transmissions are a blast, but for the older cars, the existing automatics left a lot to be desired. The gear ratios weren’t really conducive to all out performance, and frankly, for a street car, a stick is more fun, anyway.
In the case of our 2000 Mustang GT project car, which is owned by Technical Editor Johnson’s son Drew, the car was a surprise for his 17th birthday. We purchased the car from a longtime friend, and thought it to be the perfect replacement for Drew’s Ford Ranger, which had plenty of mechanical issues. The GT had new paint, nice wheels, a decent interior, and a solid drivetrain. The only problem in our minds was, the car was an automatic.
Thankfully, a car is made up of mostly nuts and bolts, so we had the confidence we could change the car over to a stick, we just needed to source the appropriate components and swap them out. This is when we consulted the experts from MPS Auto Salvage, MV Performance, Centerforce, Steeda Autosports, and DiabloSport.
To make sure we had all the appropriate components, we made a call to MPS Auto Salvage. MPS has long been known for its swap packages, regardless of what you have in mind. As long as it’s for a Mustang, MPS probably has you covered. In the case of Drew’s 2000 Mustang GT, it came with a 4R70W automatic transmission, which worked great, but with a ton of miles on the car, it had a few leaks, and seemed ready for a refresh. Also, Drew recently relayed to us that he was a little disappointed the car had an automatic when we initially gave him the car. However, he was ecstatic just to have a Mustang, so he was willing to let it slide.
The main components of the MPS Auto Salvage T45 conversion kit is the transmission, driveshaft, engine block plate, transmission harness, trans tunnel shield, and shift boot. MPS includes a clutch and resurfaced flywheel in the conversion kit, which we did need. We had a new Centerforce clutch on order, but it didn’t arrive in time for our swap, so we had to install it at a later date. MPS has several conversion kits from which to choose, whether if it’s just a manual transmission conversion like what we did, complete engine and transmission conversion kits, and everything in between.
In the end, we agreed the car definitely needed a stick, and as long as he kept up his grades, we agreed to slowly upgrade the car. When he held up his end of the bargain, we made a call to MPS for a T45 conversion kit. This swap includes everything needed to swap over from an AOD-E (1994-1998) or a 4R70W (1999-2001), including a T45 transmission, engine block plate, manual transmission harness, T45 ECU, and the correct transmission tunnel cover and shift boot. MPS’ T45 swap kit also comes with a new clutch, pilot bearing, and a resurfaced flywheel. Even though MPS does include a new clutch, we chose to handle that part on our end, choosing a new Centerforce unit with a new flywheel. We also called up Steeda Autosports for a Tri-Ax shifter, firewall adjuster, and clutch cable.
To save money we planned the swap around the 2018 Ponies in the Smokies. We drove the car to PITS, and on the way back home we stopped at MV Performance to perform the swap. MV is also twenty minutes from MPS, so if we needed more parts during the swap, we would have quick access to whatever we needed. Turns out, we did need a clutch from MPS because we weren’t able to get our Centerforce unit in time for the install at MV. However, Centerforce did come to the rescue with a new clutch, and we were able to get it installed at David Piercey’s Mustang Performance once back home in Florida.
The Centerforce 1 clutch kit and flywheel we used were part numbers 380920 for the clutch disc, CF361830 for the pressure plate, and 700205 for the 8-bolt flywheel. You’ll notice the flywheel is compatible with both a 10-inch and a 10 ½-inch clutch. The Centerforce clutch we received for Drew’s car is a 10 ½-inch unit, but pedal effort is stock-like.
When we added the new clutch, that’s when we hit a few snags. We took it for granted that the engine had a 6-bolt crank. Evidently, we weren’t paying attention when Tim and the MV crew initially did the swap. We didn’t remember the car needing an 8-bolt flywheel when we put in the used clutch with the transmission at MV Performance (Don’t expect any type of editor to remember anything…we have too much running through our heads for anything to stick). We have forgotten more than we know when it comes to Mustangs, so it was an honest mistake.
If you already know which engines have a 6-bolt or 8-bolt flywheel, go ahead and skip to the captions. If you have a 1996-2004 Mustang GT, and are unsure about your engine’s crank bolt arrangement, we can clear that up for you. The engines were built in two plants. One being the Romeo, Michigan plant, and the other being the Windsor, Ontario, Canada plant. You often hear them referred to as a Romeo-built engine or a Windsor-built engine. Romeo-built engines have 11-bolt valve covers and 6-bolt crankshafts, while Windsor-built engines have 13-bolt valve covers and 8-bolt crankshafts.
Also, the 8th digit in your Mustang’s VIN designates which engine you have. If the 8th digit is a W, you have a Romeo-built engine, whereas if it’s an X, you have a Windsor-built engine. Even so, the best way to tell which engine you are working with, count the valve cover bolts to make sure before ordering your clutch and flywheel. If the engine has 11-bolt valve covers, order a 6-bolt flywheel, and if you have 13-bolt valve covers, order an 8-bolt flywheel.
So now that we have that cleared up, let’s get this 4R70W swapped out for a T45 manual.
To prep Drew’s GT for the T45 swap, the console, automatic shifter, and steering column need to come out. The column is removed because the automatic pedal assembly needs to be swapped for a manual transmission clutch and brake pedal assembly. With the column out of the way it’s much easier to swap out the pedal assembly.
Once the interior items are out of the way, MV’s Tim Matherly and Mark Smith head to the underside of the car to begin removing the car’s factory 4R70W transmission. They start by removing the factory H-pipe, which we’ll also be ditching in favor of an aftermarket H-pipe. So, at the end of this install, Drew will not only be able to do his own shifting, but he’ll be the star of his high school parking lot, as well.
With the 4R70W out of the car, you can see the presence of fluid leaks. Even though the transmission worked perfectly fine, Drew had to constantly keep an eye on the transmission’s fluid level.
To go along with the T45 swap, MPS provided a 2001 Cobra clutch pedal assembly, and we added a Steeda Autosports Tri-Ax shifter, adjustable cable, aluminum quadrant, and firewall adjuster. These components would complete our T45 swap.
One of the most time-consuming parts of this swap is changing out the pedals. It was nice to have someone young and nimble like Mark to help perform the swap. Plus, removing the driver seat does help, as well. In the end, though, it’s all nuts and bolts, and the clutch pedal assembly bolts right in place of the automatic brake pedal. Once the clutch pedal assembly is installed, the steering column can be reinstalled.
So after driving back home using the used clutch from MPS, we were able install the new Centerforce at David Piercey’s Mustang Performance. With the new Centerforce parts in hand, we removed the T45 so we could install the new clutch. One of the first things David did was install the throwout bearing onto the clutch fork, and installing the clutch fork into place on the input shaft.
When installing a manual transmission, make sure to also install a pilot bearing; automatic transmission-equipped vehicles will not have a pilot bearing, but with a manual transmission the pilot bearing aligns the transmission’s input shaft with the crankshaft. Here, David is removing the previous pilot bearing. The pilot bearing is installed into the back of the crankshaft, and features roller bearings that the input shaft rides on, while centering it.
Pilot bearing installed
Prior to installing the new Centerforce flywheel, David adds the dowel pins to help center the new clutch and pressure plate. David hammers the dowel pins into place until each bottoms out in the dowel pin hole.
David installs the Centerforce flywheel, and torques it to spec. It’s always a good idea to have a service manual on hand so you know the torque specs for each component. Also, don’t forget to treat the flywheel bolt threads to a bit of Loctite so they don’t back out.
Installing the clutch disc is up next. The Centerforce 1 clutch disc we’re using has a sticker on it to let you know which side faces the flywheel. David is using an old 10-spline input shaft as a clutch alignment tool to place the disc up against the flywheel before he installs the pressure plate. The disc needs to be centered for when we install the T45 transmission, and so that it rides perfectly against the pressure plate.
Centerforce 1 clutch disc
Prior to installing the pressure plate, David treats the clutch bolts to a little Loctite so they don’t back out. Then using the dowel pins, he places the pressure plate on the flywheel, making sure the clutch disc is still aligned thanks to the input shaft. Tighten the pressure plate in a star pattern like you would a wheel, so it doesn’t become warped during the installation process.
Before we install the T45, we drain the transmission fluid and add fresh Dexron/Mercon fluid. A T45 takes just over three quarts, but the easiest way to make sure you have enough fluid in it is to fill it until fluid comes out of the fill hole when the transmission is as-installed in the car. Once the fluid starts to run out of the fill hole, you’re good to go.
Fortunately for us, David has a transmission jack, and that’s what we used to help get the T45 transmission into place. The T45’s bellhousing isn’t as easily removed like a T5, which sometimes makes it easier to install. However, our MPS-sourced T45 slid right into place with little drama. Once in position, David tightens the transmission bolts to the engine, before reattaching the starter.
As part of the MPS transmission conversion kit, David then installs the driveshaft, which came out of a 1998 Cobra.
Using a couple wooden blocks, David raises the transmission jack enough to attach the T45’s crossmember and mount. At this point we reattach the oxygen sensors, the transmission harness, and the H-pipe to finish up the underside part of the installation.
As for the clutch cable, even on an automatic-equipped Mustang, there is a provision for a clutch cable. In the case of our 2000 Mustang GT, the hole was simply covered up by a rubber plug. We removed the plug, installed the Steeda firewall adjuster, fed in the clutch cable, hooked it to the Steeda aluminum quadrant at the pedal, and then connected it to the clutch fork at the transmission.
To finish up the T45 swap, we added a DiabloSport Trinity (T2) Platinum performance programmer. We added the DiabloSport for two reasons. First, it allows for custom tuning, and second, its display allows Drew to see real time measurements and more accurate temperature readings. Drew can swap around parameters he wants to monitor, but it also reads error codes, as well. Plus, for a teenager, it just looks cool in the car.