Power Shift: A 6R80 Transmission Swap In The S197 Mustang Changes Everything

Since the day I installed the ProCharger P-1SC-1 centrifugal supercharger on my 2011 Mustang GT, I’ve been thinking about converting it from the stock six-speed Getrag MT-82 manual transmission over to the 6R80 automatic transmission. The MT-82 is OK if you leave your Mustang stock, and don’t ever plan to drive it hard — especially not at the dragstrip. But it’s not OK once you add a bunch more power, and after throwing several crutches at the transmission in the form of a pair of clutches and three different shifters, I knew it was time to finally pull the trigger on changing the car over to an auto. I started doing my research on the process to convert the car over to the 6R80 automatic back in 2016, and it took me until now to generate the cash and knowledge to make it happen.

The 6R80 — since it is the stock automatic transmission behind the 5.0-liter Coyote engine from the ’11–’14 S197 cars — bolts right into place with a minimum of muss and fuss. The hardest part of the process is getting the electronics to talk to each other effectively, and your mileage may vary. I won’t talk about that part of the process because it will be different for each person depending on whether they choose to use the stock PCM or the Quick 6 aftermarket transmission controller from Bauman Electronic Controls. I decided to use the stock PCM, have the PATS antitheft system turned off, and have a custom tune written by Matt Hill Motorsports. The Ford 6R80 Technical and swap info group on Facebook is where I was able to find the information I needed to complete this massive project, and thanks to them I had the confidence to tackle it. The guys in the group can point you in the right direction on this part of the project if there’s something I’ve missed. Side note: You can feel free to look me up there if you have questions and I’ll be happy to help where I can.

In my case, as I mentioned in the transmission build article from a few weeks back, I chose to use a 6R80 transmission with the configuration from the 2013 Mustang so that I could utilize Ford’s SelectShift function. This article won’t get into the details of the transmission build, as you can find them in the linked article above. I’ll provide the details of what it took to install the trans into the car and get it to work for me, and cover some of the installation pitfalls and what I learned in the process. Let’s get started, shall we?

Amazingly, changing the transmission from one to the other was the most straightforward part of the process. I enlisted one of my lifelong friends, Joel, to come over and spend the day in the garage with me. I borrowed a high-lift transmission jack from Jason Eberle (check out his awesome car feature) and we got to work.

The manual transmission was out of the car in about an hour; we pulled the console out, the driveshaft loose, and hooked the straps around the MT-82. Luckily Joel brought some of his long 3/8-inch extensions because we needed them to get to the top transmission bolts. With the old trans out of the way, we marked the crankshaft trigger wheel’s position, then removed it.

We used a simple $20 three-jaw puller I bought from Harbor Freight to yank out the pilot bearing. The tool pulled out the internal section of the bearing first, and then we were able to pull out the outer shell. The total time spent doing this was about ten minutes; I count myself lucky in this respect as I have spent hours trying to remove pilot bearings in past projects. We installed the new flexplate with a dab of ARP’s fastener assembly lube underneath the heads and threadlocker on the threads of each fastener, then torqued them to spec. See the Allen wrench Joel’s pointing at? That’s one of the tricks from Kyle’s Garage Hacks article, and it made the process of torquing those bolts down an easy one.

There is no easy way to show this part of the swap — changing out the manual trans harness for the 6R80 auto trans harness. Here’s the old harness on the floor. Brad Norsworthy provided me with the schematic, which made it easy to go step-by-step to disconnect and remove the old harness. It connects to the battery and goes across the front of the car to the alternator and steering rack, then back to the oxygen sensors and the back of the automatic transmission. Put simply, it was a pain in the ass.

One of the keys to this for me is the 6R80 torque converter from FTI Performance Products. I had been considering another brand, but seeing the performance of one of the standard-bearers of the 6R80 racing community, Scott Hasty (who is now in the high 7s in the quarter-mile with an FTI converter) had me take another look at FTI’s product line. Then I discussed the project with Bob Scheid of McLeod Racing/FTI while I was still in the planning stages, and we decided to stick one of FTI’s 3,800 stall Hard Hit lockup converters between the engine and transmission. The thought process behind using this converter is that it would help to get my full-weight pig of a car up and moving quickly both on the street and at the track. It features a triple-clutch, billet cover lockup design with furnace-brazing and TIG-welded internal fins to ensure rigidity. It’s a beautiful piece, and it’s a shame it is hidden. We filled the converter with about half a quart of Motorcraft Mercon LV fluid to ensure it wouldn’t be dry upon initial startup.

When installing the converter to the transmission, make sure it clicks in three times as the converter seats itself onto the input shaft.

Here’s where we made our biggest mistake of the day. See the converter bolt through the flexplate? Make sure you line the holes in the converter up with the holes in the flexplate before you tighten the transmission into place, because there is no way to spin the converter once the engine and 6R80 transmission are mated as one. Of course, I was off about 45 degrees, which meant that I had to stick my hand into the starter pocket and spin the converter a few degrees at a time with my fingertips until we could line the bolt holes up. It was an unpleasant task for sure.

Another tech tip I can share: lay the transmission end of the harness into place before you put the transmission up into the tunnel because once it’s up in there, you can’t get the driver’s side oxygen sensor harnesses over the transmission due to a lack of room and harness length. I was lucky enough to have a spare harness extender from the header installation I did a while back and was able to route the harness around the front of the transmission along the cooler lines. At this point, Joel had to bounce, and I shut the project down for another day. With the luxury of a lift in my garage and the heavy lifting out of the way, I could take my time through the rest of the project.

The use of the factory transmission oil cooler meant that I had to remove the nose from the car so that I could remove the intercooler and shift the A/C condenser out of the way to get the transmission cooler into place. The cooler bolted right into the factory holes.

Routing the cooler lines was another pain in the rear; it was trial-and-error to get the lines to drop into place, but once I finally figured out the routing path, all of the pieces clicked in with ease, and I was able to secure the lines to ports on the driver’s side of the transmission.

It was impossible to get my big melon and my big camera up under the steering wheel to show you how the pedal box comes out, but the important notes are to make sure you take out the seat (step 1), have a headlamp so you can see under there (step 1A), and have the necessary tools with you (step 1B). There are four nuts around the brake pedal pushrod and two more up above.

Special note: the blue brake booster rod pin that is in the manual pedal box gets thrown away as it is a one-time-use part. It is replaced with the new one seen here. There is a trick to removal: push a deep 11mm socket onto the pin end, which will depress the locking tabs and allow you to pry it out of its home with a pry tool or screwdriver. Make sure to fit the pushrod into place before installing the new pin, and the new one pops into place when the new pedal box is installed using the same nuts you removed.

I also pulled out the foam firewall plug to figure out what I was going to do to seal up the holes left by the hydraulic lines to the master cylinder and clutch slave cylinder.  I had a pair of old vacuum caps that fit the holes, so I glued them (and the foam block) into place. You can’t see this now that it’s installed as my UPR Products catch can hides the area from view. It was a MacGyver fix, but I’m happy with it, and it’s given me no issues since.

Here, I ran into another kink in the plan, for a couple of reasons. Once I had the transmission in the car, I installed the shifter and cable to check the linkage. First, I had to grind down the edge of the Dorman transmission pan to get the bracket to sit flush. I hit that with a quick squirt of paint to cover the edge I modified.

With the mounting plate for the cable in place, I had no fore-and-aft adjustment to get the cable into the proper position. I could shift the car using the linkage underneath and feel it going into each gear, but at the shifter, the indicator was not in the proper spot. To make a long story really short, if you’re using an F-150 transmission, you need to use the shifter linkage arm from a Mustang as it is longer and has a different offset to the 6R80 transmission’s internal linkage, as you can see from the photo. Additionally, I had to lengthen the slots in the PBH cable bracket to get that to sit where it needed to be — shifted to the rear of the car. Getting these items straightened out took me four nights of work, test-fitting parts, and installing and uninstalling the shifter several times until I ultimately figured out the issue.

With the hard parts installed, I moved to my least-favorite part of the project, wiring up the shifter to ensure SelectShift worked properly. I spent several more nights working on this part. Ever try to find primary wire in an auto parts store that isn’t red or black? Good luck… Thanks to my friend Scott Bowers at Ron Francis Wiring in Chester, PA, I was able to secure several different colors of 20-gauge wire to connect the shifter pigtail to the correct locations on the vehicle side.

On the shifter pigtail, I used the connections, as noted in my typed list. To do so, I ran each wire to the correct location, then used these heat-seal crimp connectors to ensure a reliable connection. On the car side, I ran the wires from the shifter location through a piece of plastic loom and out the conveniently-placed spot on the body harness grommet. I trimmed off the tip, ran the wires through, and along with the existing harness.

Under the hood, these three wires were connected to the single terminals listed in the parts list — these are the wires to the PCM. Disconnect the bottom PCM connector, use a pick for popping out the plastic blocking each of the three the pin locations (#23 for upshift, #24 for downshift, and #56 is the ground), slide the terminal into place from the PCM side, then connect it to the appropriate wire on the back side with a crimp connector. I make it sound easy, but this step took me a while.

With the wiring completed (see the schematic above for other connections), I installed the 6R80 shifter, then finished off the interior. I realized that I purchased the standard console (without Ford’s MyColor option), so I had to swap the base of the console over to retain the illumination. It’s the same part up top, and the bottom unscrews easily to move over the MyColor section.

All that glitters is not gold, however, as I discovered later. Once the 6R80 install was buttoned up, I started the car to find out that I had no reverse. After several nights of removing and reinstalling the transmission pan, following the Ford trouble tree for a no-reverse condition, replacing the lead frame (electronics), and datalogging solenoid operation, I connected with Sean to have him come over and see if he could figure out what was going on. Remember, we did not test any of these items during the transmission build since it was so clean inside. We removed the 6R80’s valve body yet again to inspect the internals, and he discovered a minute piece of debris in the valve body that was preventing the valve from operating effectively. It happens. I was just glad he had figured out the problem, as I had burned through about $100 worth of brand-new transmission fluid by this point.

Once he buttoned up the valve body and we put it back into the car, then filled the transmission, it went right into reverse smoothly and with authority. I then took it for a test drive to find out that my initial instincts of swapping this car to an automatic transmission after the ProCharger install (five years ago!) were absolutely correct.

A couple of notes: cruise control no longer works. It can be fixed with a bit more wiring and a ’13-14 gauge cluster and steering wheel switches, but I didn’t use it before and won’t use it now, so that doesn’t matter to me.

It’s been three months since I finished the 6R80 swap, and other than that initial problem with the debris, I haven’t had a single issue with anything. The driving impression is as follows: it simply kicks ass. The power delivery is so smooth and linear compared to before with the manual transmission that I can’t even believe it’s the same car. It rips in every gear, using SelectShift gives you the sensation of driving a manual without any of the drama, and the torque converter seems to be perfect. When the weather cools this fall, I’ll get it to the track and see just how much of a difference it made. I can’t wait!

Parts List (all items are from Ford unless denoted otherwise):