MANDATORY FIX - Diesel World


Rusted out, leaking oil pans have plagued ’99- 03 7.3L Power Stroke owners for years. In the diesel community, having a dripping wet oil pan is the fraternity you don’t want to be a part of but oftentimes don’t have a choice. And for truck owners living in the Midwest and Northeast, the corroding oil pan problem is all too familiar. With this stamped steel, deep drawn pan regularly exposed to road salt, moisture, and other elements, rust begins to slowly form and deteriorate its exterior. The issue can take years, even a decade, to reach critical mass, but once the fi rst pin-hole develops there will be oil under the truck everywhere it goes.


1 Engine removal is all but mandatory when it’s time to replace the oil pan on a 7.3L Power Stroke. Needless to say, a lot of components have to be pulled off of the engine in order for it to clear the fi rewall, hood, and headlight panel. Jake Bosie of Flynn’s Shop got started by removing the grille, intercooler pipes, air intake, batteries, serpentine belt, and alternator. To avoid discharging and recharging the A/C system, the A/C compressor was unbolted (shown) and laid across the passenger side fender. After that, Bosie drained the engine coolant, remove the overfl ow reservoir, unthreaded the oil fi lter, and pulled the clutch fan and shroud.


2 Next, the lower radiator to water pump outlet hose was separated, followed by the transmission cooler line being removed from the bottom of the radiator (arrow). The transmission, which had been pulled in order to be rebuilt, was already unbolted.


3 After disconnecting the main engine harness plug (located under the turbo inlet pipe), Bosie removed the high pressure line from the power steering pump (shown), which would be replaced as this is a known failure point on ’99-03 Super Duty’s (PN 1C3Z-3A717-AA). Then the radiator was unbolted and pulled out of the engine bay.


4 With the radiator out of the way, Bosie grabbed an impact and made quick work of the driver side front accessory bracket, the serpentine belt tensioner, and the passenger side front accessory bracket. The heater core hoses would be disconnected next, and positioned toward the passenger side fender well.


5 Once the turbo inlet pipe was removed, Bosie loosened the clamps securing the intake Y and fi nagled it up and off the engine. In order for the 7.3L to have proper clearance when being hoisted out of the engine bay, the turbo has to be pulled as well.


6 As was previously mentioned, the transmission had already been removed from the truck. This made accessing the up-pipe bolts near the firewall from underneath the truck much easier, and Bosie had the turbo out within minutes. From there, the fuel lines were disconnected, along with the engine ground strap and starter solenoid this is a known failure point on ’99-03 Super Duty’s (PN 1C3Z-3A717-AA). Then the radiator was unbolted and pulled out of the engine bay.


7 Making room for the engine to come forward on its way out of the truck, Bosie pulled the intercooler and then proceeded to unbolt the upper radiator core support. At this point, the engine would have ample clearance (both above it and in front of it) to be removed. Note that the A/C condenser was left in place.


8 The last order of business as far as the engine removal process was concerned was removing the motor mount nuts. There are two nuts per motor mount and they can be a tad stubborn to break loose due to rust and corrosion. The nuts call for a 21mm socket.


9 When it came time to use the cherry picker, a chain was tightly spanned between both engine eyelets and hooked onto in the middle. The initial lifting of the engine will bend the eyelets inward, which is normal. Once the eyelets had been tweaked inward, the newfound slack in the chain was taken out and the engine was ready to be lifted for good.


10 Hoisting the engine is a tedious process, as clearance between the engine to fi rewall, cherry picker to hood, and engine to A/C condenser had to be checked often. In small increments, the engine was raised and pulled forward until it was completely free from the engine bay. The engine would remain on the cherry picker for the duration of the oil pan replacement.


11 Although the pan was obviously wet from a leak, it was hard to determine exactly where the oil was coming from. As the oil pan rusts, pin-hole leaks are most common, which leads to slow seepage at fi rst, and then gets progressively worse over time.


12 The fi rst order of business once the engine was out entailed draining the oil. Then the dipstick tube was pulled. While the dipstick tube would be reused, the O-ring shown would be replaced (PN 3C3Z-6753-AA).


13 There are 12 total bolts holding the oil pan to the block. Bosie would remove 10, but leave two in place (albeit slightly loose) until he knew for sure the pan-to-block seal could be broken free.


14 A gasket scraper and hammer were used to break the seal, and Bosie started on the driver side front corner and worked his way around the perimeter of the oil pan. The RTV International used on these engines at the factory is some of the strongest silicone in the industry, so breaking the seal between the oil pan and block is sometimes easier said than done.


15 Once loose, the factory oil pan was lowered away from the block and conveniently placed on the scrap pile. Then Bosie got to work cleaning the oil pan’s mounting surface on the block.


16 After removing most leftover silicone from the block via gasket scraper, Bosie used an air die grinder to remove the rest of it. Immediately following that, the block was sprayed with brake cleaner and wiped until dry. Bosie would also make sure the oil pan mounting surface was 100-percent dry just before it was time to install the new pan.


17 While there are aftermarket oil pans available, the fact that the factory one held up to 16 winters worth of abuse made the decision to stick with an OE unit justifi able for the truck’s owner (PN F7TZ- 6675-BBB). As far as the aftermarket pans are concerned, they haven’t been out long enough for most folks to know just how long they’re capable of lasting, so the verdict is still out on that one.


18 A new dipstick tube adapter is supplied with Ford’s oil pan, but the O-ring it comes with is discarded and Motorcraft RTV silicone sealant TA-31 is used in its stead. This is because the O-ring expands and swells over time and can eventually break, leading to an oil leak that can’t be properly fi xed without pulling the oil pan again.


19 We’ll note that the dipstick tube adapter was test-fi tted prior to being coated with RTV because there are two ways to orientate it within the pan—and you defi nitely want to have the correct pitch for the dipstick tube once it’s installed. The nut used to snug up the dipstick tube adapter required a 2-inch socket, and Bosie made sure not to over tighten it (over tightening will distort the shape of the adapter and compromise its seal).


20 When it was fi nally time to install the new oil pan, an 1/8-inch thick bead of Motorcraft TA-31 was run along the pan rails. Because the oil pan doesn’t seal the greatest in the rear main and front cover areas, they were hit with a ¼-inch thick bead for added insurance (note that the entire tube of TA-31 was used). A fi nal touch of silicone was added to the four corners where the rear main seal cover meets the block, and where the front cover mates to the block.


21 Then the RTV coated oil pan was set into place on the block (a two-man job), and all 12 pan bolts were quickly threaded in via extensions and 10mm sockets. During the oil pan prep process, Bosie cleaned the threads on all oil pan bolts using a brush grinder to make their installation that much easier.


22 With all 12 bolts threaded into the new oil pan, Bosie torqued them to the recommended 18 ft-lb spec. He stressed that the front two bolts should never be over tightened, as they protrude into the aluminum front cover and the threads can easily be stripped out.


23 After letting it sit overnight, Bosie carefully set the engine back into the truck and went about reinstalling everything he’d taken off during the tear down process. It goes without saying that this is a two-day job, which should run you between $1,200 and $1,800 in labor at most reasonable independent shops. Keep in mind that with the engine out it’s an opportune time to inspect (if not replace) the rear main seal, up-pipes, and any other questionable parts that are diffi cult to access with the engine in the truck.


Perhaps even more bothersome than actually having a leaking oil pan is what has to be done in order to fi x it. Due to how the 7.3L sits in the Ford chassis, the oil pan can’t be replaced without pulling the engine—a laborious task to say the least. While there are several “repair” kits available in the aftermarket, none of them provide a long-lasting fi x. The only way to correctly address the issue is to pull the engine and install a new oil pan. This month, the folks at Flynn’s Shop in Alexander, Illinois did just that. Tag along as we walk you through the labor involved in getting a 16-year-old, 7.3L-powered work horse back on the road.


Much speculation exists as to why the Super Duty pans (’99-03) rust out more frequently than the earlier units do (’94.5- 97). Some believe a change to an inferior paint coating for the Super Duty pan is to blame, while others point the finger at a different type of steel material being used on early vs. late engines. After reaching out to our contact at Navistar, we were told that all 7.3L Power Stroke oil pans, early and late, were produced on the same tooling and by the same supplier. The fact that the pans rust out more frequently on the ’99-03 Super Duty trucks is due to the chassis configuration and where the engine is located in the engine bay. Our contact also went on to say that both Ford and International have recently switched to different oil pan suppliers for the 7.3L, which have increased material thickness and improved pan coating. The new pans are said to have started shipping out as of August of 2015.