Gumption trap: the clutch master spacer

Progress on the Mustang is slow. The car that I had driven to the tune of 20k miles over the course of three years — more mileage than most non-air conditioned classic Mustangs would see in decades in retirement as classic cars — has added zero miles to the odometer for the past year.

The car doesn’t need much work in order to be able to move under its own power. Essentially, it just needs clutch hydraulics, new brake lines, and finally the transmission, driveshaft, and exhaust installed. Any competent mechanic could probably knock this out in a single weekend day. But I’m not a competent mechanic.

Big things, easy progress

When the clutch throw out fork broke the riveted metal fulcrum inside the bell housing late last year, rendering the car unable to shift into gear, I decided to use that moment as my opportunity to install an overdrive transmission and change the rear end gear to something that wasn’t so wonky.

I pulled off the 4-speed Toploader transmission and sold it. I bought a complete T-5 transmission swap kit, which came with a brand new never installed T-5z transmission, from Modern Driveline. I dropped removed the third member assembly from the rear axle, sent it off to get 3.55 rear gear and a TrueTrac limited slip differential, and reinstalled the third member back into the car.

This was all back in May. I was 80% of the way to having a running and driving Mustang for the summer, and then all progress came to a screeching halt. The curse of the 80/20 rule came to life and threw a wrench into my plans.

The fucking hydraulic clutch master spacer

When I decided to swap transmissions, I had three options for clutch actuation. If I used the original 4-speed bellhousing, I could reuse (or rebuild) the car’s original manual rod-based clutch linkage. If I used a modern T-5 transmission bellhousing, I could use a clutch cable. Using either bellhousing, I could use hydraulic clutch actuation, with the external clutch slave requiring use of the T-5 bellhousing and the internal hydraulic throwout bearing

The Mustang came from the factory with a manual rod-based clutch linkage. This linkage has caused me all sorts of issues, and is well known for being not strong enough for long-term use with even the stock clutch. It was an easy decision not to go with the manual linkage with the transmission swap.

After talking to many of my friends who own Mustangs of many different vintages, a common refrain came to light: clutch cables were not a panacea for clutch actuation issues. They stretched, came apart, or melted next to the header. If I didn’t want to ever think about clutch actuation ever again, then clutch cables were not the answer.

That left me with one option: going hydraulic. The kit I got from Modern Driveline included everything that I needed to install hydraulic clutch actuation in the Mustang.

Step one of the process is to install the clutch master spacer on the firewall, which spaces the clutch master cylinder about 1.5 inches away from the firewall and angles it slightly inboard to make servicing easier. To do this, one must drill three holes — two for the mounting bolts, and one large hole for the clutch rod to pass through into the driver side footwell.

The instructions for installing the clutch spacer has you making your own makeshift masking tape template.

The frustrating thing is, for as nice and complete a kit as the Modern Driveline kit is, one has to go through this slightly hokey method of creating one’s own template for drilling the holes needed for the clutch master spacer out of masking tape or similar. Couldn’t a template simply be included with the kit instead of having to make it oneself? I made mine out of green painters tape and tripled checked to make sure that the holes were marked properly.

I cleaned the firewall as best I could, and tried sticking my template on the firewall. So far, so good. However, as soon as I tried drilling pilot holes for the upper and lower mounting bolts, the template would become unstuck, and I’d have to use my other hand to try and keep it in place.

Also, wedging the drill into the engine bay to drill the holes proved to be cumbersome and difficult. Notice that in the instructions, the fender apron is conveniently missing in the pictures, ostensibly to make it easier to discern what needs to be done. I found that the fender apron was keeping me from getting my cordless DeWalt drill perfectly perpendicular to the firewall.

First attempt at fitting the firewall spacer: fail. Aluminum spacer wasn’t sitting flat on the firewall, with the edge of the spacer contacting the fender apron.

I took a deep breath and drilled the two holes I needed to mount the bracket. The moment of truth came when the drill went silent. I pulled the drill out of the engine bay and took the clutch master spacer in hand, turning it around such that the two studs went through the firewall.

I had failed. The spacer would go into the mounting holes but wouldn’t sit flush with the firewall. I had drilled the holes ever too slightly close to the fender apron.


Peter Egan once reflected on the roadblocks one encounters on the long road to completing a lengthy mechanical project or vehicle restoration when he was restoring an ancient Formula Ford in his garage, expanding on the thoughts and principles written down by Robert Pirsig in the book Zen and the Art of Motorcycle Maintenance.

One problem every mechanic encoun­ters is what Pirsig calls the condition of “stuckness.”

Stuckness is when you can’t move for­ward because you can’t diagnose the prob­lem, or don’t have the right tools or parts to proceed. For instance, you’ve broken off an engine bolt during a roadside repair, but don’t have a drill or an E-Z Out to remove the broken stub from its hole, nor a bolt to replace it if you could. Meanwhile, oil is leaking out on the road. You are stuck.

Stuckness, Pirsig tells us, sometimes in­spires inventive and original solutions, but may also metamorphose into something he calls a “gumption trap.”

A gumption trap is any hurdle, psycho­logical or physical, that stops you in your tracks and drains you of the energy or en­thusiasm to continue.

I was stuck. Furthermore, I had fallen down the pit of despair and hopelessness, cursing myself for not measuring a fourth, fifth, and sixth time before attacking things with power tools, spitting angry words at 3M for the insufficient stickiness of their masking tape, and generally stopping just a few steps short of blowing hot steam out of my ears like a cartoon character.

I had fallen into the gumption trap. I put my tools away and went back inside. The Mustang would not get any attention for several months; spring and summer had arrived, and I found myself preferring to run autocrosses in silly cars, going on camping trips, and driving my Morgan around on nice sunny days rather than sit in the garage thinking about how to fix my colossal fuck up.

One week with hammers and files

After the conclusion of Nationals, I found myself saddled with almost two weeks of unused vacation time. I had originally planned on going back to China to visit family and travel to the West Coast to watch the 2017 solar eclipse, but both trips didn’t happen. Typically, I’d have used up all my vacation after Nationals, and would work almost non-stop until the last day of the year — a lonely prospect, as people inside Ford are typically very bad at using vacation until forced to use-it-or-lose-it in the month of December, making December one of the worst months for actually getting work done and transforming the office into ghost town by the middle of the month.

Clearly, I needed to use my vacation time. Originally, I thought through all of the cool road trips I could do, or sweet places I could fly to with cameras in hand. But all those things cost money, and I had a money sink in the garage that needed tending to, even if I hadn’t paid it any attention for the better part of six months. I eventually decided that I’d do a “staycation,” a completely foreign concept to me up to that point, and attempt to get the Mustang going again. After all, the list of things I needed to do were relatively short. How hard could it be if I gave myself one complete week off?

I took the week of my birthday off from work. In addition to working on the Mustang, I also earmarked a lot of that week for doing house projects that I had been meaning to get to but never did, as well as lots of running around collecting documentation needed for selling my old condo.

Still, I had time to work on the Mustang, and worked in the garage even as a cold snap moved through the area. And boy, did I need all that time.

I’ll be honest, I spent a lot of time just looking at the fuck up I had made, wondering how I could fix everything without making things way, way worse. Do I grind the clutch master spacer so it rests flat on the firewall? If I messed up the clutch master spacer, then I’d need to order a new one, which would probably be quite a chunk of change and I’d have to wait for one to arrive. I could waller out the holes I had drilled, and attempted to do so with files, but the metal in the firewall proved to be pretty thick and very resistant to the cheap Harbor Freight files I had on hand.

Eventually, I decided that the best way to deal with things was with hammers. I removed the hood of the car to give me better access for swinging my small sledge hammer around in the engine bay, and then went nuts on the area where the fender apron meets the driver side of the firewall. After several “persuasive” taps with my mini sledge, I had dimpled the fender apron enough to clear most of the spacer.

I installed the spacer backwards again, pushing the studs through the mounting holes. To get the spacer perfectly flat, I hammered the side of the spacer, using the studs to “shape” the mounting holes.

Once I was satisfied with my work, I dragged my roommate out to the garage to hold the spacer in place while I bolted in the clutch linkage firewall plate from the inside of the car. After much cursing, lying on my back underneath the dashboard, I managed to get the bolts lined up, cranking things down until the firewall plate and the clutch master cylinder spacer were perfectly flat against the firewall.

Then, I ran out of time. The staycation was over. It was time to go back to work.

Another week to drill a hole

How hard could it be to drill a 1 3/8″ hole? Pretty hard, apparently.

The instructions for the Modern Driveline kit suggest using a hole saw or equivalent for drilling the hole. I went to Lowe’s and bought myself a 1 3/8″ hole saw for my drill.

With the hole saw installed on my DeWalt cordless drill, I didn’t have the clearance between the fender apron and the shock tower to actually drill the hole with the spacer installed on the firewall. I was stuck again.

I decided to bite the bullet and buy more tools. From Amazon, I ordered a compact, corded right angle Makita drill — the drill I should have bought in the first place to drill the two mounting holes for the spacer block. With an extremely compact head, I could squeeze the drill into the engine bay and actually get a drill bit or hole saw perpendicular to the firewall.

Once the drill arrived, I took it straight to the garage, fitted my hole saw onto it, and attempted to drill the hole I needed in the firewall. The guide bit broke through the firewall, but the hole saw portion simply didn’t have the strength needed to cut through the steel. I dulled the teeth on the hole saw pretty much instantly. Stuck again.

Test fitting the installation of the clutch master cylinder to the firewall of the car.

I did some searching on Amazon, and found out that stepped drill bits going up to 1 3/8″ exist. I shopped around the local hardware, home improvement, and automotive stores looking for a local example to buy so I could finish drilling the hole right away, but no luck. I gave up and just ordered the thing off of Amazon.

Once the stepped drill bit arrived, I went back in the garage. Using the stepped drill bit on the compact right angle drill, I finally managed to get the hole for the clutch rod drilled, at the cost of severely mangling the inside of the spacer. I know that ultimately no one will ever see the inside of the clutch master cylinder spacer, but it did make me slightly angry that I’d have to remove the spacer once again in order to deburr and clean up everything.

Still, I had drilled the three holes I needed. I grabbed my clutch master cylinder and test fit it in place. Hooray! It only took me seven months and $250 in new tools to get to this point!

Next steps

The spacer has to come off for cleaning and deburring, and I need to add some paint and silicone to the firewall to make sure that nothing rusts and everything seals once the clutch cylinder spacer goes on for good. After that, I have to spend some time underneath the dashboard building the linkage that connects the clutch pedal to the clutch master push rod, which is going to suck.

Add in the fact that it’s now cold outside and, consequently, cold inside the garage, and I haven’t made any forward progress on this. And I probably won’t make any more progress on this until spring of next year.

Outside of the finishing touches of installing the lines, adding fluid, and bleeding everything, the clutch master (and internal hydraulic throwout bearing) shouldn’t take long. Then I just have to redo the brake lines and install my dual bowl master cylinder, install the bellhousing, install the transmission, reattach the driveshaft, and install an exhaust before the car is mobile. That shouldn’t take too long, right?


We’ll find out in the spring.