Crown Victoria Project Update - Building a Panther, Part 2

The gravel pit under the floor mat was the easiest to fix, and I took care of it just after I finished painting the car. I took all the seats out and pulled up the mat. All kinds of interesting stuff had taken residence under there: sunflower seed shells, sheetmetal screws, electrical connectors, earplugs, loose change, broken glass, and one .40-cal round.

The wiring to the horn had been cut to splice into the siren control. When Santa Barbara County removed all the police equipment, they left the horn wires disconnected. That was also an easy fix with some solderless connectors. The driveline thunk took a little more work to fix. After the engine had warmed up, the car would leap forward from a stop, almost as if I had a transbrake installed. The sticky throttle only exacerbated the problem. Pulling off the intake ducting, I discovered a big ridge of carbon in the throttle-body on the backside of the throttle blade, which prevented the blade from opening smoothly when the engine was at operating temperature. That was easily cleaned up with a liberal dose of carb cleaner, but I ultimately replaced it and the intake duct with a Lincoln Aviator throttle-body (right) and elbow and a Mercury Marauder intake box I purchased from ADTR.net, a company that specializes in Performance Parts for Panther Platform cars. See our Mar. ’10 issue for the feature on Chris Adams

Through some clever cross-referencing, guys have figured out the Aviator/Marauder intake parts are all larger than the stock Crown Victoria stuff, yet all the connectors and mounting tabs are in the correct locations. Check out the bigger Marauder airbox opening on the right. The Marauder intake tube also comes with a larger mass airflow sensor, which requires the ECM to be re-calibrated. I bought an SCT X3 Powerflash programmer preloaded with the correct program from Blue Oval Chips. The combination is rumored to be good for about 15 hp, and though the engine felt more responsive, dragstrip times remained the same: 10-flat in the eighth-mile, roughly 15.6s in the quarter-mile.

The new, carbon-free throttle-body partially solved the neck-snapping launches, but the problem still remained, though to a lesser extent. In addition, the car would chug a little while backing up. This led me to suspect worn universal joints or a misalignment of driveline angles. With the car on our lift, I inspected the driveshaft and rear suspension. One of the lower trailing arms was caved in slightly, hopefully during some dramatic Code 3 car chase. I also measured the driveshaft runout, which was way out of spec at nearly 0.050 inch.

Our local Pick-Your-Part junkyards provided the easy fix. It is impossible to not find a retired Crown Vic taxi in any of the ones we visit. I paid less than 60 bucks for a used driveshaft and trailing arm, cleaned them up, and plopped them in, reusing the universal joints from the donor prop shaft. This didn’t fix my driveline problems, though. At least it didn’t cost much to find that out.

I also installed a shift kit because I hate lazy-shifting automatic transmissions. Known online as the J-Mod (named after Ford drivetrain engineer Jerry Wroblewski), it’s not a shift kit per se. Rather, it involves replacing the stock valvebody separator plate with one from a Mercury Marauder. You also replace a couple of the accumulator springs. This is a fairly simple job and works for all 4R70W transmissions. A thorough write-up is available on the Thunderbird and Cougar Club of America’s website: tccoa.com. Quicker shifts are the result because of bigger fluid passages and more line pressure. Rebuilding the transmission ultimately fixed my driveline problems. The clutch friction material was almost nonexistent, all the bearings were worn out, and there was a ton of endplay. Read about that in our Jan. ’10 issue.