Join Date: Aug 2006
Location: Parker County, TX and Santa Fe County, NM
Mentioned: 2 Post(s)
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Re: Is a Valve Adjustment really necessary??
It doesn't have lifters, it has overhead cams, the bucket-type shims between the cam lobes and the valve stem. You can check the clearance with a feeler gauge, but to adjust the clearance you have to remove the appropriate cam shaft and replace the bucket shim(s).
Overhead cams with bucket shims will stay in spec for a long long time once they're set up right in the first place, because there is so little slop and essentially no moving parts between the cam and the valve. As a single point of reference, My valve clearances were all well within spec at 90,000 miles when they were checked as a side note to some warranty work. Same with my Sequoia when I replaced the timing belt at about the same mileage. I don't remember when the maintenance schedule says to check the valve clearances, but most people under semi-normal circumstances will not need to have them adjusted for well over 100,000 miles I would guess, and maybe not even then.