adjust valve lash by pushrod or valve stem clearance?

[whitebroncoii87]

I have 87 broncoii with 2.9l. Should I adjust lash by tighten down adjuster nut based on lash between rocker arm and pushrod or rocker arm and valve stem? If valve stem should I put a feeler gauge (what size) in between or just visually confirm they are barely touching then 1 1/2 turn thereafter (whereas pushrod is 1/2 after they have touched).. Thank you

 

[adsm08]

You shouldn't need to adjust the valve lash on a 2.9. It's a hydraulic lifter, self adjusting.

If they are noisy, that is fairly common as the engine ages. The fix usually ends up being camshaft bearings.

 

[whitebroncoii87]

What if I'm changing out the lifters? How should I adjust a fresh install?

 

[AndyB.]

Service manuals are your friend.

On cylinder to be adjusted, positions cams to that the tappets are in the base circle area. Then loosen adjusting screws until a distinct lash between the roller arm pad and the valve tip end can be noticed. Note: plunger of hydraulic tappet should now be fully extended under load of internal spring.

Then carefully screw in the adjustment screws, until the roller arms lightly touch the valves.

To achieve the nominal working position of the plunger, screw in the adjusting screw 4.5 turns, equivalent to 2mm (.07 inches) plunger travel into lifter.

 

[adsm08]

Set the cam so the valves are closed on the cylinder you want to work on, back out the adjusting screws until you have a distinct lash, then run them back in until the arm just touches the valve and go another 1.5 turns.

 

[adsm08]

To achieve the nominal working position of the plunger, screw in the adjusting screw 4.5 turns, equivalent to 2mm (.07 inches) plunger travel into lifter.

Andy, check your turn count. My book says the exact same thing, except it says 1.5, not 4.5.

 

[AndyB.]

It seems like a lot to me, too. Maybe a typo in my book?

 

[adsm08]

Possibly. What book were you using? I had the 87 Ford shop manual in front of me.

I'm pretty sure 4.5 turns is gonna go in a lot more than .07".

 

[AndyB.]

1986 Truck Shop Manual. Page 21-20-4. It does say, "The information on this page has to be revised please refer to tab 85-25-21 for additional information."

I just figured there were some really fine threads.