318/360 Timing Chain Replacement
(Check manual for types, amounts and applicability)
Basic Socket Set
9/16" 6pt deep socket
Basic combination wrench set
Gasket Scraper Tool
Small 2-jaw Puller or Bolt Style puller
Large Seal Installation Tool
Air ratchet (recommended for time)
Torque wrenches (both lb-ft and lb-in)
Timing Chain Set
Timing Chain Cover Gasket Set
Water Pump (recommended)
Upper, Lower and Bypass Hoses (recommended)
Hose Clamps for above
Loctite 515 or equiv
Oil Change (recommended)
5-6 Hours with clean-up
Motor is original with 130,000 miles on it. During a tune-up, I checked the timing I found it was extremely advanced indicating stretch in the timing chain. After reviewing my Haynes manual for the steps, I decided I would replace the water pump (it was original also), the upper, lower and bypass hoses, and if you need it, you can do the thermostat while you are working this repair. Start by disconnecting the battery and thoroughly draining the coolant. I also recommend draining the oil as well.
Remove the drive belt. Remove the fan shroud and fan clutch as outlined in the Fan Clutch Replacement article.
THe Haynes manual says to mark the #1 cylinder location on the distributor body and then remove the cap. Using a large socket and breaker bar, turn the crank clockwise until the rotor is aligned with the mark you made on the distributor body. If you are going to be changing the timing chain, this step is not absolutely necessary as you can go through the disassembly and before removing the timing chain itself, you can turn the crank and align the timing marks that way.
This is basically all the items you will be removing. The fan shroud, fan clutch, crank pulley, vibration damper, power steering pump, alternator, A/C compressor, idler pulley, accessory bracket, water pump, cooling hoses, and timing chain cover.
Remove lower radiator hose. Unbolt heater hose return line. There is a tab holding the metal portion to the engine and also a small o-ring about 1/2" from the. If you are not replacing the water pump, do not damage this o-ring. If you have not replaced the water pump, I highly recommend that you do it at this time. A new pump is only $45-50 with a $7-10 core. A new water pump should come with a replacement o-ring.
Remove the water pump pulley if you are going to replace the pump. Most versions are the 4-bolt type, but there are some with a press-on pulley. Be sure to check the type prior to purchasing your new one.
Remove the power steering pump bracket from the engine and set it aside. You do not need to remove any hoses. There are two long bolts on the driver side, a short bolt on the pass side bottom and a bolt/stud on the upper pass side. This stud holds several ground wires. Remove the nut holding the wires, then you can use a deep socket to extract the stud.
Now you need to remove the alternator. This will also gain you access to the upper radiator hose clamp on the thermostat housing. While you are here, you will need to remove the oil dipstick hold down.
You can now completely remove the alternator. Once the alternator is loose, you will see which wire you need to remove in order to place the alternator back on the valve cover to get it out of the way. Please note the pics are a bit out of order since the Haynes manual left out several steps that I realized later.
If you are replacing the hoses, again something I highly recommend, remove the upper radiator hose from the thermostat housing. You may have to cut the hose to remove it. If you are going to replace the thermostat, again highly recommended, you can do so at this time, or see the Thermostat Replacement article for additional info.
Remove the bypass hose clamp. Remove the water pump bolts. Be sure to keep track of which bolts go where as there are three lengths of bolts used. You can figure out which bolts go where, but it is easier to track them from this point.
Again, this pic is out of order, but its time to remove the A/C compressor. There are 4 bolts holding to the accessory bracket. Three are easily removed. The one under the metal lines is a bit more difficult. You will not be able to remove it, but there is just enough room to unthread it from the accessory bracket. The rear of the compressor is held down by a black bracket, but you can easily slide the compressor out from under it once unbolted. DO NOT REMOVE ANY LINES FROM THE A/C COMPRESSOR! Also, you will need to disconnect 2 wiring harnesses from the A/C compressor. One on the driver side and another to the rear under the #1 fuel injector.
Move the A/C compressor to the top of the engine. Use caution so that you do not kink or damage any of the lines.
You can now remove the accessory bracket, however you will need to unbolt the black strut that goes from the top of the bracket to the top of the intake manifold. This is where the air box connects on that little nub to hold the front end in place. You will also need to remove the idler pulley in order to the reach the last bolt. When replacing the idler pulley at the end, I suggest cleaning it out and greasing the bearing.
Remove the remaining bypass hose and cover the thermostat housing with a rag to keep debris out. Clean off the top of the timing chain cover. This is a good point to clean off any additional dirt and debris from the top of the motor.
Now you need to remove the vibration damper. This bolt is torqued to 135 lb-ft so you may need to remove the starter and have a second person jam a screwdriver in the flywheel teeth to keep the crank from turning. I was able to get the bolt off without doing that.
It was recommended in the Haynes manual to use a bolt style puller to thread into the crank pulley bolt holes. You do not want to pull from the outer edge of the damper as it can bend it. I used a small 2-jaw puller fished through some holes between the pulley holes. I kept the bolt in the crank, by about 3 threads in order to have something to press against. The damper is about 2-1/2" onto the crank nose, so it may take a few minutes to pull the damper off.
With the damper off, you can inspect the woodruff key in the crank nose. If you needs to replace the front crank seal, you can remove the damper only and then replace the seal. You will need to remove the front two oil pan bolts as they thread into the timing cover.
Remove the timing cover. There are 4 bolts or studs holding it place after all the other accessories are removed. Two of these bolts are studs that hold the tranny lines and the ground wire. Promptly shove a rag into the oil pan opening at the bottom of the block to prevent debris from entering the oil pan. USE CAUTION REMOVING IT AS YOU DO NOT WANT TO DAMAGE THE OIL PAN GASKET. If you do, you will need to drop the pan and replace it. See the Rear Main Seal Replacement if you need to remove the pan.
For comparison, I checked the slack in the OEM chain. The OEM chain uses nylon coated teeth on the sprockets for noise control, but that covering wears off allowing the chain to run loose. The OEM chain is also a bit different from most chains I have seen. It is not a double row of teeth, but a single tooth and the chain itself have "U" shaped links instead of the typical "dogbone" shape. This setup does not let the teeth pass through the links, just sit between the pins that hold the links together. Definitely new to me.
Now you need to spend a bunch of time cleaning parts. Remove the old gasket material from the engine block. Clean the timing cover inside and out, the coolant passages and remove the front crank seal from the timing cover. The seal goes in from the front, so you will need to knock it out from behind.
Install the new crank sprocket onto the crank nose. Set the keyway based on the advance or retard you wish to use. I selected 4* advanced because advancing the timing typically nets more power at lower RPMs. Retarding the timing results in more top end power.
Install the chain and cam sprocket. You may need to lightly tap the cam sprocket on. It uses a keyway as well so ignore the timing marks for now. Once the chain is on, turn the crank so that the timing mark on the CAM sprocket is straight down or straight up depending on what the OEM setup was. On my truck, the crank/cam timing marks were based on the #6 cylinder TDC. On a 4 stroke, 8 cylinder motor, single cam, this is acceptable. Once the cam sprocket timing mark is setup, you can remove the cam sprocket and chain. Then turn the crank by itself until the timing mark on the crank sprocket is straight up. Reassemble the cam sprocket and chain. You may need to slightly adjust the crank in order to get the chain to line up with the crank teeth. You just set the crank-cam timing. Now, apply a light coat of clean engine oil to the chain and sprockets. While the gains of 4* advance would be more noticeable on a non-computer controlled car, you should see some improvement in overall drivability. In the Rams, the PCM controls the ignition timing via crank and cam position sensors.
Install a new crank seal into the timing cover. Install the timing cover gasket by applying a light coat of RTV to both sides of the gasket and then sticking it to the block. Also, apply a bead of RTV to the point where the oil pan contacts the block following the gasket to the front along the inside corner. Carefully set the cover in place. Take note of the oil pan gasket as it wraps around the front "U" of the pan and is easily displaced. Install the two bolts from the oil pan at first in order to pull the timing cover down into place. Reinstall the remaining the timing cover bolts and tranny line bracket. Reinstall the vibration damper. You will most likely have to use the crank bolt to seat the damper after it is aligned with the keyway. Reinstall the crank pulley. Be sure it is centered and tighten the bolts in a cross pattern.
Reattach the power steering pump and the wires removed in the process. Install the new o-ring on the heater return hose.
Install the water pump gasket with a light coat of RTV on both sides, similar to the timing cover gasket. Install the water pump itself. Carefully place the bolts back in the proper order. Some bolts thread into aluminum timing cover, some through the cover into the block. Install a new bypass hose and clamps.
Reinstalling the remaining parts in reverse order. I recommend cleaning and greasing the idler pulley prior to reinstalling.
Replace all the coolant lines, wire harnesses, and verify no extra pieces. Refill coolant and oil. If you think you got some coolant into the oil pan, you may need to pour in a quart or two of oil and immediately drain it. Button everything up and start the motor. Check for leaks. Bring the motor up to operating temp and check coolant levels.
Update 8/23/03, Notes:
1. You don't have to completely remove the water pump if you don't want to change it. Just the 4 bolts by the inlets.
2. The power steering pump can be left in place.
3. To help with loosening the dampener you can use a small socket in one of the balancing holes of the dampener. It will contact the water pump and make short work for the big crank bolt.