For a complete guide on rebuilding the DT466, click on the book sales tab above this post.
An additional note: click on the DT466E Inframe Rebuild tab above the posts to go to the sales point for my book on the subject.
Bruce Christopherson
Hello, and welcome to the third and last installment of the survey on an inframe overhaul of an International DT 466. So far we have pulled the head and pistons, cleaned and inspected everything, and replaced some bad parts. We slid the liners in and checked them for protrusion, then installed them for real with new O-rings.
Hopefully by now the block has pretty much stopped dripping oil and we can go under to replace the main bearings. Of course, every time the crank is turned the motor will burp out some more, but that’s just part of the charm of the job. The back of each bearing shell is stamped with its size. A standard size will be stamped “std” and I always check to see that each shell I pull out is standard size also. I’ve never had it happen, but it is possible a remanufactured, undersize crank has been installed. Main bearings are installed one journal at a time, lubricated with a little clean oil or assembly grease. The back of each shell must be absolutely clean and dry. Keeping the shells clean is always the biggest challenge during installation, but a piece of dirt on the back of a shell can reduce bearing clearance. Examine each shell for signs of damage, overloading, excess wear, or overheating. a high-mileage engine may have the bearings worn so that the copper layer under the surface babbit will show and often have scratches on the surface, but the crank journals should have a defect-free, mirror like appearance. The top bearing shell can be a challenge to install properly. To remove the old bearing,I start it out by carefully bumping the end with the tip of a screwdriver, then lever it out with a small ladyfoot prybar with a sharpened end. The sharp tip of the prybar will dig into the back of the bearing and you can roll it out. Care must be used so the journal surface is not scratched with a steel tool. Installation of the shell is sometimes more difficult. Care must be taken that the sharp edge of the engine block doesn’t raise a burr on the back of the shell while it is rolled in. Some guys like to put a roll it in using a large cotter pin in the crank oil hole and turning the crank, but I never had much luck doing that. I push it in with my fingers as far as possible, and then finish it with a pusher made of aluminum strip or a brass punch. Whatever the method, it sometimes takes some patience to do the job without damaging something. Installing the cap and its new shell is straightforward, just put a clean shell in the cap, lubricate it, and install it oriented the same way it came out. The bolts must be tightened evenly so the cap seats properly. The rear main bearing is the thrust bearing that restrains the fore and aft movement of the crank. Before the thrust bearing bolts are tight, pry the crank back and forth to set the clearance, then check clearance with a dial indicator after the bolts are torqued.
Piston installation naturally starts with putting new pistons onto the rods. Changing pistons requires no tools, except for a pair of snap ring pliers. The pins are a precision fit to the pistons and rods. The fit is so close that, although they are installed by hand, they are often a little fussy to put together. The ends tend to catch in the relatively soft aluminum of the piston pinhole. Don’t use a hammer on them, or the piston will be damaged. If the fit is too tight to slide together, put the pistons in some hot water before assembly and they should go together easily. The pistons have valve reliefs and are stamped for the cam side, which must be oriented correctly to the rod. Rings are installed in the usual manner and with the gaps spaced around the piston circumference, then installed with a good ring compressor. They should slide into the bore with little pressure and no catching or hanging up. The oil ring combination especially is somewhat fragile and if one gets hung up on the edge of the liner opening, is easily damaged. The best policy is if there is any doubt, to pull the piston back out, check for damage, and try again. Another caution is to avoid damaging the piston oiler on each side of the lower cylinder, but this is seldom an issue. The rod is pulled onto the crank from below, being careful that the rod bolts don’t scratch the crank journal, and the cap bolted up with a new bearing shell.
After the bearings and pistons are installed and everything double checked, the oil pump pickup is bolted up with a new gasket, then the pan installed. The pan has a tendency to leak if not installed properly. The pan flange should be cleaned up with a Roloc wheel, and the gasket glued to it with a gasket adhesive with the side marked “top” up. I like brush-on adhesive, as the spray-on stuff never seems to hold the gasket in place until the pan is up. When the pan sealing surface of the block is cleaned with a Roloc be careful on the ends, as these are the bottom of the aluminum front cover and rear seal carrier, and can be damaged if you are too aggressive. No sealer needs to be used on the block side of the pan gasket, except for a small bead of a good-quality silicone on each angled corner, and a dab where the front cover and rear seal carrier meet the block. Bolt the pan up (use the eight shorter bolts on the ends), and tighten to spec. If these guidelines are followed, the pan should never leak.
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| liners and pistons are in, ready for the head |
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| injector set with new o-rings, ready to go in |
After the head is cleaned up, the injector bores cleaned and inspected, and any other work needed is done, the head can be installed. Installing the high pressure oil manifold is easier with the head off the engine, but the sensor may need to be removed to prevent damaging it when the head is installed. I never try to drop a head on a block by myself. I have a trusted helper run the fork lift or hoist, and I guide the head down and direct traffic. The head must come down evenly and slowly so that the edge of the block doesn’t crush or cut the gasket. If in doubt, lift it back up and look. Oiled head bolts are inserted and torqued. Note in the repair manual that feeler gauges must be used on the rocker shaft next to the end pedestals. If clearance is not provided during torquedown, the pedestal can bind the shaft, causing damage when the engine is run. Also note that the headbolts are torque-to-yield, requiring an extra 900 turn after the final torque.
The rest of the engine assembly is straightforward reverse of teardown. A new valve cover gasket is not required unless it was damaged. A new oil filter is filled with fresh oil and the crankcase and radiator refilled. I do everything I can to make sure the engine starts quickly after priming. Priming is done with the injector harness unplugged at the valve cover. Crank the engine until good oil pressure shows on the gauge, which should happen after only about 10 seconds of cranking. I crank a couple of more times to make get oil circulating through the whole engine, waiting between times so the starter doesn’t get hot. When the injector harness is plugged back in, the engine should start immediately and should run smoothly after half a minute or so. After it runs for a minute, I shut it back down and check for leaks and fluid levels. I don’t believe in letting a new engine sit and idle for very long. As soon as it runs smooth and fluids have been checked, I set the idle at about 1000 RPM and let it run for 5 minutes to ensure I have no leaks, after which I take it right out on the road for a short test drive followed by another visual and fluid check, followed by a test drive of maybe 10 to 20 miles. This type of shakedown will expose any leaks or drivability problems. A customer paying for a repair of this size deserves a trouble-free, leak-free vehicle.
Well, that is the end of this posting, thanks for checking it out.
Bruce Christopherson
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