Adjusting valve lash

From V6SHO
Jump to: navigation, search

Procedure

It isn't much more difficult than changing the plugs. Two special tools are required to compress the valve spring and then hold the shim guide down while the shim is popped out. Clearances are checked using a feeler gauge and by gauging the size of the shim needed to replace the original. The SHO Shop and SP Motorsports offer a tool kit "rental" basically for doing the 60K maintenance. This kit includes a set of different sized shims.


Tips / Hints

Remove your hood !!!!! It's easy, takes 5 minutes and makes the job MUCH easier.

Identify all the nuts/bolts/vacuum hoses with a label made of masking tape. Makes re-assembly easy.

Once your into the cams, keep the car in gear and push it back and forth to reposition the cams for measurement.

The valve buckets have a slot to extract the tappets. Rotate the bucket by hand to position the slot so that you can get a small screw driver under the tappet.

The left rear intake manifold bracket is a pita to get off. First remove the 13 mm nut (all others are 12 mm) with your box wrench. This nut holds a wiring harness. Once you slip the wiring harness off, then you can loosen the 12 mm nut with the other box wrench and the bracket will come off.

Tools you'll need

tappet depressor (curved fork with fingers that grow thicker as they reach the handle) tappet holder (L shaped piece with the bottom thickness just right for holding the bucket down)

torque wrench

5mm male allen socket

feeler guage (0.006 - 0.015 in)

magnetic pickup to extract the tappets

4 cans intake cleaner for fuel injected cars - to clean the manifold

1 tube black (high temp) sensor safe RTV

1 tube anti-seize for bolts going back into aluminum

12 13mm flat box wrenches

If you find any clearances out of spec your also need a micrometer to measure the tappet.

The tappet depressor and tappet holder are manufacturered by OTC, most Ford dealers won't have them or know how to get them.

303-344 Compressor, tappet

303-345 Holder, tappet


OTC

655 Eisenhower dr

Owatonna MN, 55060


800-533-6127 customer service

800-283-8665 fax


Why it's important Thanks to Doug Lewis.

It's important to do the valve adjustment. It's not because the valves will be out of adjustment; it's that the shims have a service life. The shims will wear without affecting the valve clearance. The shims are hardened to one specific hardness less than the cams, the idea being that the shims will wear first.

99% of the time you won't find any valves out of spec, but you will find shims that are worn. The wear looks like dirt that you can't wipe off. Once the outer hardness (softness!) is worn thru, it starts to wear the cams. Look for chips or spots in the hardening. If you find any, replace the shim. This means that after you measure the clearance with a feeler guage, you MUST remove the shim to inspect it. If it is worn in any way, it must be replaced. If you have to replace a shim, try to get the lash for that valve in the middle of the clearance range (0.008;" intake, 0.012;" exhaust). The full valve spec range is as follows: Intake: .006 - .010 Exhaust: .010 - .014

I cannot stress this enough. The valves must be adjusted at 60K, not for clearance, but for the life of the shims and the cams. Too many times, I have found worn shims and worn cam lobes that could have been avoided by doing the maintenance at the right time.

When you re-install the valve covers, put a thin film of black RTV on the seals for the spark plug tubes. This will keep the tubes from filling up with oil, which will cause a miss on acceleration from 1200-2500 RPM. If oil fouls the spark plug wires, the wires will have to be replaced (after you replace the seals at $25 each x 6).

If you wish to replace the valve cover and intake seals, there is a kit available from FelPro (part #VS 50378 R) that is MUCH cheaper than the equivalent parts from Ford. It comes with left and right side gaskets and six sparkplug tube seals. The tube seals are still made by Yamaha for the gen1 engines.