2003 Ford Crown Victoria - Ring an Pinion - Part 7

2003 Ford Crown Victoria Ring And Pinion Part 7 Ring Gear Bolts Tightened

2003 Ford Crown Victoria Ring And Pinion Part 7 Gear

In our Oct. '11 issue, we added 70 hp to Project Panther using new cams and cylinder heads from Trick Flow. In the process, we raised the rpm where peak torque and horsepower occur. Since this is a heavy car (4,000 pounds) with a small (281ci) engine, we want to launch the car as close to the new torque peak as possible and help acceleration by increasing the torque multiple at the axle. Fortunately, Ford Racing has the best prices on 3.73:1 ring-and-pinion and bearing kits for the 8.8, so I ordered up a set and called Tech Editor Smith’s buddy Tim Moore, who agreed to do the install. While this is something I’d like to be able to do myself, I don’t have the collection of pullers, drivers, and presses, not to mention the wealth of knowledge and experience Moore has at his disposal. In some cases, it’s better to let a pro do the job, and I am not ashamed to admit this is one job I was willing to hand over to someone experienced. Though the job itself is a dirty one, the removal and replacement of the differential carrier is pretty straightforward. Installing the pinion gear at the right depth is where finesse and skill are required. Get it wrong and at best your final drive will howl like straight-cut gears; at worst, you can burn up the pinion bearings. Moore got it right, of course, and the result is a quiet-running gearset and a more responsive car. Translation: It accelerates faster.

Hate all these Crown Victoria articles? That’s cool. Close your eyes and visualize this axle under your favorite Ford. The 8.8-inch came in nearly every FoMoCo rear-drive application for almost two decades. The job we’re showing here works across the board.

In this month’s Project Car update, we are swapping out the stock 3.27:1 gears for a more beefy set of 3.73s. To get started, Moore removed the driveshaft and rear brake calipers, popped open the rear cover, and removed the differential cross-shaft. Ford’s 8.8-inch uses C-clips to retain the axles (incidentally, they’re referred to as “U-washers” in the factory service manual), and access to the clips is somewhat limited by the S-shaped spring in the Traction Lok diff. Moore used a couple of small screwdrivers and picks to remove them. He slid the axles out just far enough to clear the differential carrier. Next, he removed the carrier caps, pried out the carrier, and removed the pinion gear.
In this month’s Project Car update, we are swapping out the stock 3.27:1 gears for a more
He cleaned the housing with some brake cleaner and drove the front and rear pinion-bearing races with a long driver. Ford Racing’s install kit came with new bearings and races. Moore used a hammer and punch to drive them in place.
He cleaned the housing with some brake cleaner and drove the front and rear pinion-bearing
Moore removed the ring-gear retaining bolts and used a brass punch to remove the 3.27:1 ring gear from the carrier. The ring gear is designed to be pressed onto the carrier, so it required a lot of hammering to free it from the ring gear flange.
Moore removed the ring-gear retaining bolts and used a brass punch to remove the 3.27:1 ri

Moore dressed the mating surfaces of the carrier and the new 3.73:1 ring gear with an abrasive stone lubricated with penetrant.
Moore dressed the mating surfaces of the carrier and the new 3.73:1 ring gear with an abra
According to the service manual, the new ring gear is supposed to be pressed onto the carrier. When Moore slipped the new gear on, the gap between the gear and carrier flange was longer than the retaining bolts. Instead of pressing the gear on the rest of the way, Moore used bolts that are longer than stock to draw the gear on, then he replaced them with the stock ring-gear bolts. He put red Loctite on the threads prior to torquing them.
According to the service manual, the new ring gear is supposed to be pressed onto the carr
Moore used an impact wrench to tighten the bolts, working in a star-shaped pattern. The spec listed in the manual is 77 ft-lb. Moore knows how much torque his gun makes and therefore knew how much to tighten them without having to get out the torque wrench.
Moore used an impact wrench to tighten the bolts, working in a star-shaped pattern. The sp

When this car was assembled, the guys at the plant set up the ring-and-pinion with the correct combination of shims to prevent gear noise. Because we are using Ford parts, theoretically, the original combination of shims should work. So Moore pressed the bearing off the pinion to reuse the stock pinion shim. “That shim goes with that case; it should work with these new gears, too. With factory gears you can usually reuse the stock shims. But you’re usually not as lucky with aftermarket gears. You will have to install them, check the pattern, and remove or add shims until the pattern is correct,” Moore says.
When this car was assembled, the guys at the plant set up the ring-and-pinion with the cor
Moore dropped the stock shim onto the new pinion, slipped a set of homemade checker bearings on the pinion gear, and installed the pinion into the case to check both lash and pinion depth. Checker bearings are honed to eliminate the interference fit, allowing them to slip on and off and thus making the setup process much quicker. Because the stock bearings need to be pressed on, if Moore needs to add or replace shims, he will have to press off the bearing, add new shims, press the bearings on, and repeat the process until he gets the combination correct.
Moore dropped the stock shim onto the new pinion, slipped a set of homemade checker bearin
Moore coated a few of the teeth on both gears with a gear-marking compound and ran them in contact together. He inspected the wear mark left in the dye to determine whether the gears were meshing properly. “You don’t want [the wear marks] too close to the top of the tooth. It should be a nice, round pattern somewhere on the middle of the tooth,” Moore says.
Moore coated a few of the teeth on both gears with a gear-marking compound and ran them in

The pattern was fine, so Moore removed the checker bearings, pressed on the new pinion bearings, and reinstalled the pinion.
The pattern was fine, so Moore removed the checker bearings, pressed on the new pinion bea
What’s the big deal about shims? The pinion-bearing adjustment shim (official Ford terminology!) controls how far into the case the pinion gear fits, and the differential bearing shim controls the lateral (side-to-side) location of the ring gear. If this relationship is off, you can end up with noisy gears and/or broken teeth because of incorrect or insufficient contact between the ring-and-pinion gear teeth. Here, Moore is checking lash, the amount of free movement between the ring-and-pinion teeth (i.e. how far he can turn the ring gear while holding the pinion stationary). The spec is 0.010 to 0.012 inch.
What’s the big deal about shims? The pinion-bearing adjustment shim (official Ford termino
Tightening the pinion nut crushes a collapsible washer on the pinion and determines the preload between the pinion and the bearings. Again, there is a spec for this (20 in-lb, according to my service manual for new bearings; it’s slightly less for used bearings), but Moore knows how much to tighten it by touch. He spins the pinion by hand and can tell by how much drag he feels when the pinion nut is tightened sufficiently.
Tightening the pinion nut crushes a collapsible washer on the pinion and determines the pr

Next, Moore reinstalled the differential, using a hammer and brass punch to fully seat it in the bearing cups. The caps were tightened to 77 ft-lb. He pushed the axles back in, fitted the C-clips, and reinstalled the pinion cross-shaft and locking bolt. He put the brake calipers back on but made me put the wheels back on. The 9-inch-wide steel wheels and 285/40R17 tires (see our Dec. ’11 issue) weigh a good 60 pounds each, and all I’d been doing so far was standing around taking pictures.
Next, Moore reinstalled the differential, using a hammer and brass punch to fully seat it
Royal Purple hooked us up with a case of 75W-90 synthetic gear lube with a limited-slip additive included. Fluid capacity is about 33⁄4 pints.
Royal Purple hooked us up with a case of 75W-90 synthetic gear lube with a limited-slip ad
Because my car is equipped with an electronic speedometer, recalibrating it for the new axle ratio is as easy as plugging in my SCT X3 Power Programmer, selecting the corresponding axle ratio, and reflashing the ECM. Older cars will require replacement of the speedo gears in the transmission tail housing.
Because my car is equipped with an electronic speedometer, recalibrating it for the new ax

2003 Ford Crown Victoria Ring And Pinion Part 7 Driveshaft

In addition to my speedo being out of whack, my entire driveline is operating at higher speeds with the new 3.73:1 gears installed. In Overdrive at 75 mph on the freeway, the engine is now running at 2,500 rpm, an increase of about 600 rpm. It is important to ensure that the rest of your driveline, specifically the driveshaft, is capable of operating under these new conditions.

In addition to my speedo being out of whack, my entire driveline is operating at higher sp

Determining Driveshaft Critical Speed

Here's the formula for determining driveshaft speed:

Road Speed x 336 x Rear Gear
__________________________
Tire Size

Checking my car running down the freeway:

75 x 336 x 3.73
____________ = 3,686 rpm driveshaft speed
25.5

This chart, provided by DynoTech Driveshafts, offers a guideline for safe driveshaft speeds. DynoTech General Manager Steve Raymond says operating above the critical speed and spinning faster than intended can cause the driveshaft to bend. As it bends, its overall length will shorten, causing it to pull out of the tailshaft of the transmission. In extreme cases, the driveshaft can even come apart, unspiraling like a paper towel roll. According to the formula, at freeway speeds, I’m well below the critical speed of my car’s 31⁄2-inch-diameter, 56-inch-long aluminum driveshaft (measured at the centerlines of the universal joints). However, on a recent trip to Willow Springs International Raceway, I reached speeds on the track of 100 mph, or 4,941 driveshaft rpm. Dynotech’s Raymond determined that my car can safely go about 144 mph. I doubt I have the horsepower to go that fast, but some readers’ cars might. If so, we recommend replacing the driveshaft with one that better matches the car’s operating conditions.

Parts List
Description	PN	Source	Price
Ford Racing 3.73:1 ring-and-pinion set	M-4209-F373N	Ford Racing Performance Parts	$179.95
Ford Racing deluxe ring-and-pinion install kit	M4210B1	Ford Racing Performance Parts	162.00
Max Gear75W-90 gear lube	01300	Royal Purple	19.22 (qt.)