Volume 3 - Valve Adjustment

Prior to adjusting your valves, the engine must be completely cooled down. The night before, park your car in the location you plan on doing the work and let it sit overnight.

First things first - you'll need a few items.

Required Items

19mm wrench - I prefer a box end type.

13mm wrench - Again, a box end is highly recommended.

Medium sized flat bladed screwdriver.

.006" feeler gauge.

2 new valve cover gaskets

Recommended Items

Trouble light

Floor Jack (the car's jack will work also)

2 Jack stands

Clean Rags

Something to catch oil drippings, a flat oven tin works great for this.

Prepping the vehicle

I like to jack the car up and place it on jack stands, it's fairly low back there and any lift of the rear end will make the job much easier. If you are going to jack the car up with a floor jack, place the jack's contact plate under the flat part of the pan directly in front of the transmission and lift the car. This will lift both wheels off the ground together. Place the Jack stands under the torsion tubes (large circular bar going across the chassis directly in front of the transmission and lower the car on to the stands. Make sure the stands are squarely under the torsion housing. (Note: Never work under a vehicle that is suspended with a jack) Place the catch tins under the cylinder heads and remove both valve covers by placing the screwdriver under the center of the valve cover bails (wire clips holding on the valve covers) and prying upward. The bail will move upward releasing the tension on the cover and you'll be able to work the cover off. Some oil will drip down at this point, don't worry, it will be a small amount. Once it finishes dripping, use a rag to clean it off the heat exchangers (if you're not sure where the heat exchanger is, don't worry it's the thing covered with oil). Lastly you need to remove the distributor cap. The cap is held on by 2 clips, insert the screwdriver toward the top of the clip between the clip and the cap, gently pry outward and the clip will pop off the notches in the cap. Don't remove the wires or the rotor inside the cap, just pull the cap up off the distributor and place it to the side suspended by the sparkplug wires. Now you are ready to adjust the valves.

Note: The adjustment of each cylinder's valves must be done at a specific crankshaft location (top dead center for that cylinder). Failure to place the engine in a specific location will result in misadjusted valves and possible engine damage if it's run. THe 19mm wrench is used to to turn over the engine by the generator/alternator pulley bolt (bolt holding the upper fan belt pulley on). If the belt is loose, it may slip as you turn the bolt, when this happens, I grab both sides of the belt as it enters and exits the upper pulley and squeeze them together with one hand while I use the wrench to turn the pulley with the other, this will increase the tension enough to turn the engine over by this method.

The valve adjustment is started with cylinder #1, this is forward most cylinder located on the passenger side of the vehicle (figure 1). There is two valves associated with each cylinder, intake and exhaust. Each cylinder head handles two cylinders so there is 4 valves per head. The two outermost valves are exhaust and the two inner are intake (figure 2). Exhaust valves typically require adjustment more often as they are subjected to higher heat causing the valve to slightly stretch decreasing (tightening) the lash (gap). Valves are measured between the top of the valve and the adjusting screw (figure 3).

FIGURE 1

FIGURE 2

FIGURE 3

Valve Clearances:

1954 ~ 1960 (36HP) (Intake - .004") (Exhaust - .004")

1961 ~ 1965 (40HP) (Intake - .008") (Exhaust - .012")

1966 Up (Intake - .006") (Exhaust - .006")

Since we are starting at cylinder #1, we have to place #1 at the top dead center (TDC) location, this is done by watching the distributor rotor. There is a small notch (oriented at 4 o'clock) cut into the top edge of the distributor where the cap meets the metal distributor body. The trick is to rotate the engine until the rotor is pointing directly at the notch. When it is lined up, look down at the crankshaft pulley (large pulley at the lower end of the fan belt). There will be a notch cut on the inside edge of the pulley that lines up with the split in the center of the engine case. If you are not sure of the marks or you think you might have another pulley installed, here's a link to Rob & Dave's discussion on the subject. It's a good idea to paint the notch with a small amount of visible paint (whiteout works for this but doesn't last). Line the notch up with the split, your engine is now at TDC for cylinder #1. Both rocker arms for cylinder number 1 should have a very small amount of play between the rocker arm and valve. If they don't, your valves are really tight or the engine isn't at TDC for #1. At this point I always check the rocker shaft nuts, these are located between the intake and exhaust rocker arms. They should be tight. Now, using the feeler gauge, measure the gap between the adjusting screw and the top of the valve for both the intake and exhaust. Sometimes the gauge won't fit between the adjuster and the valve stem, in that case break the lock nut loose on the adjustment screw, loosen the screw one turn and insert the feeler gauge. If it requires more than one turn to get the gauge inserted, double check your TDC.

Note: I like to check the gap prior to loosening the lock nut, this allows you to determine what the lash was at prior to any changes, this can be helpful in the early detection of problems with the valve train. Make note of this measurement for future reference.

Once the gauge is inserted in to the gap, tighten the adjusting screw gradually while sliding the gauge back and forth until there is a noticeable"drag". There is a developed "Feel" when it comes to measuring valve lash, many will tell you that this is critical to a correct valve adjustment. While it's important, the novice can develop this feel by using a go/no go method measure the valves. Just adjust your lash to the correct amount, lets say .006" then attempt to insert a .007" feeler gauge into the gap, if it goes, your adjustment is too loose, if it doesn't (no go) and the .006" does (go), you are ok. Of course someone is going to come back and tell me that they crammed a .007" into the gap, if you tried hard enough, you can probably squeeze one in but if it's "very difficult" to insert then you are probably where you need to be. At this point you hold the screw in it's location with a screw driver and tighten the nut with the 13mm wrench. Don't make the mistake of cranking down really hard on the lock nut, this is not necessary and causes thread wear in the adjuster which makes for difficult adjustments in the future. It should be tight but not overly so. Recheck the lash once the locknut is tightened down, if it's out repeat the adjustment. Once you have completed both the intake and exhaust valves for cylinder #1, you are ready to move to the next cylinder. The procedure is exactly the same for the other cylinders but you must relocate each cylinder to it's TDC point. Since the firing order on a VW engine is 1-4-3-2 we adjacent the valves in that order.

At the rear of the car using the 19mm wrench, turn the engine clockwise so the crankshaft (large) pulley turns 1/2 turn or 180 degrees. There will be another notch on the pulley exactly 180 degrees or half way around from #1's TDC point. Line this up with the split in the center of the case and repeat the adjustment procedure on cylinder # 4. Rotate the crankshaft another 1/2 turn clockwise until the original notch is lined up with the split in the case, adjust cylinder #3. Rotate the crankshaft another 1/2 turn and adjust cylinder #2. Your valves are now set. Replace the distributor cap, ensure the cap clicks into the locating notch in the distributor housing and set the hold down clips. Lastly, remove any traces of the valve cover gasket from the head and valve covers. Place the new gasket into a valve covers and place the cover on the head. Lift up the bale till it clicks into the notch in the valve cover, A screwdriver may be required to get it the last of the way on. Clean the bottom of the engine, remove all oil residue and recheck the oil, add as necessary. Start the engine and listen for loud tappet noise, (clicking at idle), if it's present, you may have mis-adjusted one of the valves. Check for oil leaks.

Chris R.