12mm socket
10mm socket
10mm ring spanner
Ratchet with extension bar
Large flat screw driver
Small quantity of engine oil
6 pack
smokes
Before I go on - word of warning: This is NOT for amatuers... you need a reasonably sound knowledge of mechanics to get this right.
Also note - this is based on the front bank of cylinders. I will go into more detail about the rear bank later in this post. Essentially the job of replacing tappets is identical on both banks, just that there is a WHOLE lot more parts that need to come out to get at the rears... that & the angles you physically are working in are best left for Pilates instructors
First up - remove the 6 x 10mm bolts on the rocker cover plate
Next up, remove the 6 x 10mm bolts that hold the coil packs in place. Unplug the leads from the coil packs first. Be gentle when you remove the coil packs as they are connected to the spark plug boots. The whole assemble will come out of the spark plug guides.
Remove the 9 x 10mm bolts that hold the rocker cover down. These bolts can be an arse as they go through both the rocker gasket & rubber grommets. The grommets are to seal the oil in the rocker. When you undo the bolts they really dont want to unscrew all the way out of the grommet without a fight - thats fine cause we dont need them all the way out. Once they are un-threaded from the head, thats all you need to do.
Now remove the 3 x 10mm bolts that hold the cam belt cover to the rocker cover.
Remove the vacuum pipe & pcv valve & line from the rocker cover. These just slide out. If they are a bit stuck, gently lever them off the a small flat screw driver. Also time to remove the oil filler cap.
Now to remove the rocker cover.... can be tricky. Chances are if its been on a long time it will be stuck to the head. What we want to avoid is tearing the cork gasket that seals it to the head. DO NOT try and lever the cover off with a screw driver - you may well slip and tear the gasket. Easiest way I found was to give the rocker cover a couple of light taps with a rubber mallet. It jarred it free, then it just lifts off. Again being carefull when lifting it off not to catch it on anything & ripping the gasket.
Low & behold - this is the view that you will then see....
And your tappets are located under the rocker arms - see pic
Now for a bit of tech talk - the basic operation here, is the cam rotates its eliptical lobes around > these lobes push down on the rocker arms > the rocker arm pivots off the tappet > the rocker arm depresses the valve. Reason for the tech talk is because at any given time on the GR motor, there are 6 vavles that are depressed in each head - either fully or just about to. Meaning that you cannot attempt to remove a tappets that is under load - ie depressed. This following pic may help. The tappet on the left can be swapped out - the one on the right cannot because the valve is open (ie under load from the cam / rocker assembly)
If you want to get really technical about: if you rotate the motor till its at TDC (Top Dead Centre) where No.1 piston is at the top of its stroke) you can do 6 of the 12 tappets in one go. You can then rotate the motor 180 degrees (No.1 at the bottom of its intake stroke) and then do the other 6 tappets.
Or, if you're a dodgy prick like myself, you can just give the ignition a flick & the motor will turn a bit & roll the cams off the tappets you need to get at. I needed to flick the motor 3 times to get at them all.
Your new tappets should look a little like this:
Now to lever the old ones out. This is by no means a science, you lever of whatever you can find, just DO NOT lever of the cam lobe itself. You can do serious damage if you scratch the crap out of a cam lobe, then drive off at 9,000 rpm.
I just levered off the edges around the head.
Tip: because these are oily buggers, I only used one hand to remove them. Keep your other hand clean to lever with the screw driver (learnt that the hard way!)
If you dig the screw driver to far under you may end up try to lift the tappet out as well. Just re-adjust your lever till you have just the rocker.
Try to lever the rocker up & across to the side a little just enough for it to still sit on the tappet, but not properly. You can then re-adjust your lever to keep going.
This is where it gets scary - now knock the rocker off all the way. As its sprung loaded it may fling off. It usually lands in the area around the tappet that is hardest to get at with your fingers. When you develope a technique, you can avoid this springing business.
Now just remove the tappet by sliding it out of its seat. You can remove the rocker arm as well.
Comparison of old & new. Note the wear and tear around the edges of the old tappet body and on the tip.
Also note on the new tappet - you can see how much I can compress the spring loaded tip. That is almost impossible to do on a worn one. Stiff as you like....the main reason for 'tap! tap! tap!'
Now to install the new ones. Ensure you give the new ones a good lube with oil. Then just slide back into the head.
Tip: GO SLOWLY when reinserting. Why? Becasue the hole that it sits in has an oil gallery running off it. If you go in quick - you will push the oil in the line, that line inturn pushes the oil out into the head via another oil gallery. It just so happens that the oil gallery into the head squirts straight up - into your eye!! (also learnt the hard way)
Now it gets a little fiddly. Rest the rocker arm back onto the valve tip. You then have to lever the tappet end of the rocker arm back up onto the tappet. Pics can only do so much to describe this. Need to do it to know. I got quite nifty at this & was able to do them first go. Some times when you lever the friggen rocker pops off the valve & falls into the head etc etc etc... just check the pics
Now all you have to do is repeat that 11 more times!
Or 23 more times if you are doing the rear bank as well. All done:
Re-assemble every thing in the reverse order that you took it off. Only thing to note - do not tighten the rocker cover bolts excessively. They are pinching a cork gasket to the head remember. Only needs to be nipped up.
Now as mentioned, the rears are a nightmare to get at. Procedure is the same, but the intake manifold need to come out. As a DIY on this has already been done, Im not going to do it again - just use this one:
http://www.ftooc.org/phpbb/viewtopic.php?t=23905
Genuine from Mitsubishi, these tappets are $35 odd dollars each - when you need 24 that adds up very quickly. Kempys do these aftermarket units for $240 a set of 12 - $480 all up.
Garages will also charge like wounded bulls to do this work and you will be told that the cams & rockers assemblies need to be completely removed in order to do it. I've heard of quotes upwards of $2000 with gen parts.
The front bank took me just over 2 hours in total.
The rear bank took me over 4 hours in total.
This post has been taken from ftoaustralia
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