How to install the timing chain on explorer 9798 4.0 sohc there are not marks or guides to install the left side and front timing chain and you am thinking probably you need some kind of special tool?

Answer 1

First of all, that engine was designed by aliens. No one from this planet could have ever dreamed this thing up. You not only need a special tool, you need a whole set of special tools. We have a large case full of pieces to special holders and alignment tools for the cam shafts and the crank shaft on that engine. Everything has to be aligned with those tools, and held into place with the special holders, while the chains are being installed. There are probably 15-20 pieces to that set of special tools. Not only are there no timing marks, there are no woodruff keys on the gears either, so if you take the bolts loose, the gears freewheel on the camshafts. So you have to have the special tools to align and hold the camshafts themselves, while you tighten the gears down onto the camshafts. You will not get that engine timed without the tools. Also, that engine is an interferrence engine. In other words, it bends valves if you crank it over out of time. You also are supposed to remove all of the cam rockers before working on that engine, because simply turning the crankshaft or a camshaft while installing the chains can bend valves.

FOUND A WAY Alignment of the Ford 4.0 SOHC engine is easier than it looks. The basics are the main jack and crank shaft gears have timing marks that point toward each other in alignment with the center of the crank and jack shafts. The key way on the crank and the wide notch on the damper pulley are in line with the center line if you can not find the TDC mark on the damper. Set the crank at TDC with the timing mark (mine has marks I just needed to clean the rust off) or line up the wide notch or key way with the center of the jack shaft which you can see threw the front RT timing chain area. Make sure your came are set with the narrow side of the slot opposite the drive gear toward the head and almost in line with the head. There is a point where the valves do not hit the pistons and you will need to be there for the next step. If the valves hit the pistons while turning the cam you will need to move the crank until they clear then set the TDC. The cams are a little trickier. On the end of the cam opposite the gear is a slot. It is 6mm wide. When you look at it the slot is off center so one side is on the center line of the cam shaft. Position the cam shaft so the short side is facing the engine. Alignment is made by placing a clamp that cost too much money on the head with a bar that holds the slot parallel to the head. Conveniently the center line of the shaft is 42mm (1 5/8") form the head. I took a bar 1 ½ X 1/8" to span the head and laid a 1/8" thick bar on top to enter the slot. The cam shaft on the gear end has an area with flat sides that a wrench can be used to hold the cam while setting it. While holding the bars and cam in place check TDC and tighten the timing gear. If you want to buy the tools they are at www.denlorstool.com. Search (OTC 6488 kit) part # rotunda 303-577 (T97T-6256-c) a roller cam removing tool makes life easier in that you do not need to worry about bending valves. While on valves a quick check for a bent valve…. Position the cam with closed valves and piston down all the way. Use your compression tester extension hose to adapt the spark plug hole to an air line. You will need an air tank with a about 5 gal. on a good compressor. Apply the air and check for leakage from exhaust and intake. You will have some because the valves seat for 300bls and you are only putting in 100 or less but a bent valve will blow by worse than the others.

good luck and don't bend your valves