Rocker arm slack
11-20-2016, 01:41 PM
#1
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Rocker arm slack
I have a 1988 Toyota 4runner 22r that I have been working on and asking questions here on YotaTech and everyone has been awesome at offering advice. I now have another question. I was in the process of setting the timing after replacing the head gasket when I noticed slack in the rocker arms. When the camshaft timing mark is at the very top the first two rocker arms has about 1/16" slack which I think is normal however, the second and third rocker arm ( on the right side of the head} has approximately 1/2" slack. When the cam shaft rotates it doesn't move the valves very far. The head was recently reworked by a machine shop and nothing has been changed. Is this much slack normal?
Last edited by Poppie51; 11-20-2016 at 01:45 PM.
11-20-2016, 02:28 PM
#2
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Ah, Not even close.
The correct valve lash between the rockers and cam is measured in thousanths of an inch.
The lash is measured when a cam lobe is on the base circle portion of its circumference and should be about .008in on the intakes and .012in on the exhaust valves.
The FSM states that the adjustment should be made on a hot engine.
Some folks disregard this though, and set them cold.
I am one of those.
I set them cold @ .009in and .013in respectively, and the regular, light, sewing machine like tapping tells me that my 22Re is a happy engine.
The correct valve lash between the rockers and cam is measured in thousanths of an inch.
The lash is measured when a cam lobe is on the base circle portion of its circumference and should be about .008in on the intakes and .012in on the exhaust valves.
The FSM states that the adjustment should be made on a hot engine.
Some folks disregard this though, and set them cold.
I am one of those.
I set them cold @ .009in and .013in respectively, and the regular, light, sewing machine like tapping tells me that my 22Re is a happy engine.
Last edited by millball; 11-20-2016 at 02:40 PM.
11-20-2016, 05:12 PM
#3
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If you are inexperienced with the use of feeler gauges, a set of Go-No go gauges is the tool for you.
When the clearance is correct, the front of the leaf will pass and the .002 thicker base of the leaf will not.
http://www.ebay.com/itm/WILW80524-Pe...291663&vxp=mtr
When the clearance is correct, the front of the leaf will pass and the .002 thicker base of the leaf will not.
http://www.ebay.com/itm/WILW80524-Pe...291663&vxp=mtr
11-20-2016, 06:52 PM
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Thanks for the replies. I'm not a mechanic but I knew that didn't look right. I'm not sure why they are so far off especially since it hasn't been long since it was taken to the machinist. I installed the head and put everything back together and the engine would crank but wouldn't start so maybe this is my problem. Thanks again for the responses.
