timing chain repair

How To Replace Falcon 6Cyl Timing Chain and Guides – Part One

Today we are looking at what is involved in replacing the timing chain and chain guides on the overhead cam engines found in E series Falcon’s. Typically you would only need to do this job if either the timing chain is noisy (and the noise has been confirmed as the chain) or you’ve spotted a worn or broken chain guide while doing something else or if you are unlucky enough a guide has broken and the chain has smashed a hole in the timing case – don’t laugh, it is a surprisingly common problem.

Our donor car for this tutorial must have had this issue at some stage as the timing cover is obviously from a wrecker and a small piece of the block has been broken off where one of the cover bolts goes through and the bolt now has a nut on the end of it 🙂 .

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Anyway, enough rambling, let’s get into it. As always please read through all of the steps before contemplating doing the job to be sure you can manage it and have the necessary tools and/or equipment.

We need to remove the radiator so the first thing you need to do, before moving the car to your work area, is remove the bottom radiator hose (at the radiator end only for now) and drain the coolant.

Next up, remove the two bolts securing the air intake and remove it and the top of the air filter box. You might also want to move the air filter out of harms way.

Completely remove the top radiator hose and remove the expansion tank hose from the thermostat housing and pull it out from under the fan shroud and out of the way.

Now we need to remove the cooling fan. This has a 22mm LEFT-HAND-THREAD nut that connects to the waterpump shaft. To remove it you either need a thin 22mm spanner or a long-ish cold chisel or solid flat-blade screw driver to knock it loose. Obviously the spanner is the preferred method of removal but I have removed many without damaging the waterpump the other way. Here is how we use a cold chisel to loosen the fan – place the cold chisel on the right hand side of the nut, one or two solid hits and it should come loose. Once it’s loose it’s just a matter of spinning it off but remember that it’s LEFT-HAND-THREAD so it will feel like you’re tightening it up!

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Once you have the fan removed from the waterpump undo the two phillips head screws that hold the fan shroud to the radiator and lift the shroud and fan out together.

Continue with the radiator by removing the two other expansion tank hoses and the transmission cooler lines (17mm spanner needed here). The bottom cooler line will leak transmission fluid so use a drip tray if you have one handy.

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Now you will be left with the two 15mm radiator mounting bolts (one either side). Remove these and with a bit of juggling the radiator will lift out.

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Be sure to store the radiator where it won’t get damaged and make sure that you don’t lose the two bottom rubber insulators (one each side again).

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Next up we need to start removing the belts. The first cab off the rank is the power steering belt. Loosen the 24mm nut (a 15/16 spanner/socket will fit also) and then rotate the tensioner anti-clockwise with a 13mm spanner to loosen and remove the belt.

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The alternator/waterpump belt is next. Before removing the belt we need to loosen the four 10mm bolts holding the waterpump pulley on so that it doesn’t get in the way when the timing cover is removed. These bolts can be quite tight so if you find the pulley rotating as you try to undo the bolts wedge a screwdriver between the shaft and the opposite bolt to the one you are loosening. If you have it a single hex socket is a good idea here also as the bolt heads can be rounded off pretty damn easily.

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The belt is removed by loosening the 13mm top alternator bolt and then rotating the 24mm adjuster nut in a clockwise direction.

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If you’re having trouble moving the alternator you may also have to loosen the bottom bolt (which makes things a bit easier further on anyway)

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And last but not least for the belts is the air conditioning belt. It’s removed by loosening the 24mm nut and rotating the tensioner anti-clockwise.

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Now we can remove the power steering and air conditioning belt tensioners. There are three 10mm bolts to remove for the p/s tensioner…

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And a T30 torx head bolt at the bottom of the a/c belt tensioner.

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Now we need to move the power steering pump out of the way so that we can remove the timing chain tensioner. The pump doesn’t have to be completely removed so we can leave the hoses attached, just remove the two 13mm bolts on the front bracket and the 17mm nut at the rear and then move the pump back a bit and over to the side.

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At this point it is a good idea to work out how we are going to remove the harmonic balancer bolt. If you have a compressor and impact gun you’re laughing as long as the gun fits between the bolt and the a/c condenser. 

Even if you don’t have access to air tools you still have two methods to choose from. The first involves locking the crank up by either removing the starter motor and wedging something between the ring gear and the bellhousing or block and using a ratchet or breaker bar to loosen and remove the bolt. You could also make up a balancer locking tool like this one HERE to stop the crank from rotating (yes it will work on a Falcon engine also).

The other method (and the one I favour when I can’t use the impact gun) is to fit a socket and breaker bar onto the bolt and let the breaker bar come in contact with the chassis of the car (protected by a block of wood) and then briefly activate the starter motor. Although primitive, this method does work! Here is how you set up the socket and breaker bar…

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When you are absolutely sure that there are no bodies in harm’s way hit the key for a second or two and with any luck the bolt will crack loose.

The reason we do this step now is because we need to disconnect the battery before going any further so when you have the balancer bolt loose, disconnect the negative terminal of the battery.

Next on the list is the top and bottom alternator brackets. To gain better access completely remove the bottom radiator hose and remove the 13mm and 10mm top alternator bracket bolts. There is also the alternator wire clip that needs to be removed from the bracket.

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If you haven’t done so already, the alternator top bolt/tensioner can be completely removed now also so that the bracket can come right out.

Now for the bottom alternator bracket. This bracket runs around the timing cover so it has to be moved, but we can get away with just removing the bolts and moving it and the alternator to the side. There are three 13mm bolts into the block and one 10mm bolt through the timing cover. One of the 13mm bolts is hard to see and you may have to lay the alternator over a bit before you can get a socket onto it.

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Up next is removing the tappet cover.

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Start by numbering the spark plug leads to their corresponding cylinders using a permanent marker, this saves a lot of confusion later if they get mixed up! To remove the leads from the spark plugs use a twisting and pulling motion, rather than just trying to yank them straight off. Take the leads out of the plastic separators on the tappet cover and lay them over the intake side of the engine.

The next step is to get the accelerator/cruise control cables out of the way. To do this you need to remove the plastic 17mm nut from the thread on the accelerator cable and slide the inner of the cable out through the cut-out.

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Next twist the cable at an angle to remove it from the ball on the throttle linkage.

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And then remove the clip off the end of the cable before loosing it!

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Removing the cruise control cable (if fitted) if pretty much self explanatory. Then we can remove the hose to the PCV valve at the front of the tappet cover, and remove the breather hose at the rear.

Then we can remove the four 13mm nuts that hold the tappet cover on, you will have to use a spanner on the back one. Be sure to remove the seals as well before lifting the cover off. The bracket on the back one for the brake booster vacuum hose can stay attached to the hose and not get in the way too much.

The tappet cover might take a little bit off persuasion to get moving (tapping on the side with a soft hammer is better than levering between it and cylinder head) and it will take a bit of maneuvering to get it over the back stud and out of the way. Take it easy, lift the front up and try different angles and you will win!

With the tappet cover out of the way it’s time to remove the harmonic balancer. The bolt should already be loose and now you can completely remove it. Typically you will need a puller for these balancers, something like the one pictured below works well, but as a last resort you could try two levers opposite each other between the balancer and the lip on the sump/timing cover and gently ‘rocking’ them backwards and forwards. Not usually successful but worth a go if you’re stuck.

The threads in the balancer that you will need to use with a puller are M10 x 1.5 and the bolts will need to be about 80mm long.

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With the balancer removed it’s time to remove some of the sump bolts so it drops down enough to remove the timing cover. I use a 1/4 inch drive ratchet with two extensions and 8mm socket. You can get to all of the sump bolts with this setup, including the ones above the crossmember.

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The first two sump bolts on each side have to come out, they bolt into the timing cover, and we need to remove/loosen enough bolts to drop the front of the sump down. I completely remove all bolts except the last three on each side, these are loosened 4 or 5 turns.

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And this is how far the sump drops… heaps of room.

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Now we can loosen the camshaft sprocket bolt. Doing this now makes things easier when it comes time to completely remove the sprocket. Our camshaft bolt had a 16mm head but from memory the original is 17mm. A sharp ‘knock’ on the end of the ratchet should see it crack loose. Don’t completely remove it yet.

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At this stage it is a good idea to check that the valve timing is roughly lined up. Typically there is a mark on the camshaft sprocket that lines up a few mm above the passengers side of the head (for timing chains with yellow links in them see THIS ARTICLE). As long as the timing is in the ball park we’ll be right, but if it’s way out refit the harmonic balancer bolt to the crankshaft and rotate the engine clockwise until it’s lined up again.

The next step is to remove the Timing Chain Tensioner. See THIS ARTICLE for instruction on this step.

Now we can remove the 3 remaining bolts in the timing cover. These should all be 10mm.

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The time has finally come to remove the cover! Carefully prise the cover forward, starting from the bottom. As it’s coming out we need to be sure that the bottom chain guide comes with the cover and doesn’t fall into the sump. There is also an O ring at the top of the cover that seals the tensioner oil gallery, this can also fall down as the cover comes off. Once the cover is removed stuff some rags into the gap between the sump and the block so you don’t have to go fishing for anything in the sump oil!

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Now we can check all three timing marks to make sure they are correctly aligned before removing the chain and guides. As we saw earlier, the camshaft timing mark typically lines up above the head on the passenger side and the crankshaft and distributor drive shaft marks should line up together.

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The next step is to remove the timing chain. To do this we need to completely remove the camshaft sprocket bolt and remove the 10mm bolt that secures the chain guide to the cylinder head. This bolt can often be very tight and to avoid rounding off the head I suggest using a single-hex socket.

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Now we can gently lever the sprocket off the camshaft, let the chain drop down a bit and remove the chain from the crankshaft and distributor drive sprockets. Then you should be able to lift out the camshaft sprocket, timing chain and top guide all in one unit. The remaining chain guide is removed by undoing the 10mm pivot bolt.

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The final tear-down step is to clean all gasket surfaces (leave the sump gasket in place and as is) and give the timing cover a clean up and gather your new parts.

Typically you will need –

  • New Timing Chain and Guides (3 of)
  • Timing Cover Gasket Set
  • Silicon Sealant (Ultra Blue or similar) for gasket between top of timing cover and cylinder head. This will leak without sealant!
  • Non-drying gasket goo for timing cover to block gaskets, Permatex Aviation Form-A-Gasket is a good one.
  • Plenty of patience for the reassembly!

Speaking of reassembly, Part Two can be found HERE.

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