Ok, now that we have it all apart it’s time to fit the new parts and time for the scary bit – putting it all back together without any left over bits! Just kidding, it’s a piece of cake really.
The first thing to do is give everything a good clean, in particular the gasket surfaces of the timing cover, block and underside of the cylinder head. I can’t stress enough that it is vital that these surfaces are clean and free from foreign material. There is nothing worse than spending a few hours re-assembling the engine to find out you have an oil leak caused by a dirty gasket surface 🙁 I use a single-sided razor blade for cleaning gasket surfaces and I still think this is the best way to be sure you have a nice clean surface.
The timing cover itself needs some work before it’s ready to go back on, namely replacing the front seal, fitting the bottom chain guide and tensioner oil gallery O ring. The front seal is easy enough, knock out the old seal from the inside and then carefully knock the new one into position.
The bottom chain guide simply pushed into position and the O ring is best fitted with a dab or two of grease to hold it in place when you fit the cover.
Once the cover is sorted we can fit the new left hand side chain guide (passengers side) to the chain.
The next step is to lower the chain (and guide) into position over the crankshaft and intermediate shaft sprockets, taking care that the timing marks still line up and there is no slack at the bottom of the chain between the two sprockets.
While keeping the chain in this position we can then fit the camshaft sprocket, ensuring that all the slack in the chain is on the drivers side (as pictured above). The camshaft sprocket timing mark should be just above the passengers side of the head (unless it’s a ‘hybrid’ engine with yellow links in the timing chain- see THIS ARTICLE). NOTE – The camshaft gear on our donor engine is an adjustable Crow item and although in the same place, the factory timing mark is a ‘line’ rather than a ‘dot’.
Next we can fit and tighten the camshaft sprocket bolt. I always use Loctite on the thread just to be sure and so we don’t mess up the chain and timing marks (and the valves for that matter) we need to limit the amount the camshaft will turn. An extension bar onto a head bolt usually does the trick.
At this stage we can also fit the 10mm bolt through the cylinder head and top chain guide (red arrow in the pic above). It’s a good idea to dab some sealant on the thread of this bolt also as it tends to leak oil otherwise.
Once that’s done we can also bolt up the new drivers side (tensioner) chain guide. Once again a bit of Loctite on the bolt thread is good insurance.
Ok, we are almost ready to refit the timing cover and start bolting everything up but before going any further I suggest one last check of the timing marks.
The crankshaft mark and intermediate shaft marks should be facing each other, all of the slack in the chain should be on the right hand side (drivers side) and the camshaft mark should be just above cylinder head level on the passengers side.
If that all checks out ok it’s time for the fun part! The gaskets between the timing cover and block need all the help they can get to stay in position so I suggest coating both sides with Permatex Aviation Form-A-Gasket and then fitting them in position on the engine block. The Permatex is a non-drying sealant that is sticky enough to help the gaskets stay in the right spot and obviously it helps to stop any leaks.
I also suggest putting two dabs of a silicon sealant (Ultra Blue for example) in the corners where the block, head and timing cover meet, as shown in the pic below.
And I highly recommend a good coating of silicone on the gasket that gets sandwiched between the timing cover and the underside of the cylinder head. This has long been a problem area for oil leaks on these engines and depending on which model you have the timing cover may have gaskets locating ‘cutouts’ on the top surface.
And finally, some silicon around the bends and corners of the sump gasket won’t go astray either. With all of this in place it’s time to fit up the cover.
As the gasket between the cover and the underside of the head does literally need to be squashed into position the best way to fit the cover is to push it into position, slightly lower than it needs to be and then either push or lever it up until the dowels in the bottom bolt holes of the cover locate in their positions in the block. Keep in mind that the bottom chain guide must go into position under the chain and we have an O ring in the top that needs to stay in position also. Sounds difficult, but it’s really not too bad, honest 🙂
One side dowel and where it fits into the block.
Gently lever the cover up into position one side at a time.
Once you have the two dowels in position I suggest fitting the first three 10mm timing cover bolts (or two 10mm and one 12mm bolt in our case – broken block).
The next step is to make sure that the gaskets are in their correct positions and it shouldn’t be too hard to loosen the bolts and make any adjustments to the gaskets if need be.
Now it’s time to fit the tensioner. You want it in the retracted position and as you push it into it’s hole in the timing cover try to line it up so that it sits correctly against the guide. See THIS ARTICLE for info on resetting the tensioner.
The rest of the job is simply following the steps in PART ONE in reverse order, with attention to the following couple of things –
- When it comes to fitting the harmonic balancer, smear a light film of oil where the timing cover seal will run. This will stop any squeaking and while you’re working with the balancer turn the engine over a couple of times by hand (well ratchet and socket actually) to make sure everything is working as it should. The action of doing this should also tighten up the balancer bolt enough as well!
- Try not to over-tighten the sump bolts. If you see the gasket spreading out the sides you’ve gone too tight.
- Take the chance to clean the core of the radiator of any leaves and grass etc and refill the cooling system with a quality coolant.
- When you refit the cooling fan (left-hand thread remember!) spin it to get it hand tight and then a gentle tap with a cold chisel and hammer will be enough to tighten it up if you don’t have the spanner to do it.
- It’s a good idea, if you haven’t done so already, to fit a rubber tappet cover gasket and replace the seals on the studs. Be careful not to over-tighten the nuts also as the tappet cover is easily cracked.
- I think that just about covers it. Best of luck.