| Valley of the Evil Valve Lash Adjusters |
| In response to many many questions... I've started this page to show the valve adjusters in all their evil... Reference to evil is only in jest due to my great dislike of this design. I mean, who in their right mind would put something so in need of oil pressure at the END of the oil supply food chain? The valve lash adjusters look and act sort of like hydraulic lifters, but there function is much different. In the SBC, the lifters are bathed to a larger degree in oil. No problem usually. They ride on the camshaft lobes and provide the bump to the pushrods, in turn moving the rockers and pusing down on the individual valves... OK? Moving on, in the 3 liter V6, early versions had a hardened section of the rocker arm that rode directly on the cam lobe. Later versions had roller rockers for reduced friction and wear. Anyway, the rockers ride directly on the cam lobes, oil hits the cam journals in the cam caps and then flows through the rocker shafts to the rocker arms, and in turn, into the lash adjusters, which are pushing down on the valves... The adjusters are at the very end of this chain... Dumb isn't it? |
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| See? These things aren't that big are they. NAPA stores MAY carry them for $7.99 each. Autozone carries them for $11.99 a piece! Kragen and everyone else is higher... And you would need twelve to swap out the whole bundle. It does seem that the adjusters remained pretty much the same throughout the production of the 3.0. And they are the same for the Mitsu Montero/3000GT/Diamante SOHC motors as well... |
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| They have a small spring loaded checkball in them that maintains oil inside the adjuster and relieves any air that gets in there. Remember what I said about needing adequate oil pressure? That is why. A little leak down over night will allow them to "tick" a bit in the morning, or when cold, but SHOULD go away after a time. If not, then you either need new adjusters, have low oil level or the oil pump is giving way, or worse, time for new crankshaft main bearings... |
| The Mitsubishi 3000 GT and Mitsu Montero and others also use versions of this motor. Even the Dohc 24 valve motors use a version of this adjuster. So, why is it left at the end of the oil supply food chain? I don't know!!! Swapping in new adjusters is relatively easy. First, prep the new adjusters by soaking them in diesel fuel. Hold them upright in the fuel and poke a very small stiff wire or allen wrench through the hole and push down on the check ball. You should see an air bubble the first couple times. Move to the next till all are done, and repeat. Then, remove the valve covers (also, swing the alternator out of the way, some completely remove it. Some folks even remove the plenum and intake manifolds to gain easier access to the rear bank), loosen the cam caps (6 LONG 12mm bolts) but do NOT remove the bolts. Carefully lift the caps, so you can swing each individual rocker arm up to remove the adjuster. Pop in the new one (filled as above) and move to the next.. When done, replace the covers, and start the motor. Let it idle for a bit so the adjusters finish filling with oil, and then, I hope your noise is gone. Obviously, this is a simplified version of the work to do... |