Adjusting Valve Clearances on an Auto?

[Admin/Founder 2]

Ive been Pondering this one for a while whats the correct proceedure for adjusting the valve clearances on an Automatic A Series?

I have two service Manuals a good old genuine BL and a Vague Haynes

The BL one just tells you this


but doesnt mention how to open or close the valves whereas the haynes one does but it seems a bit of a palarva for an auto?

It is important that the clearance is set when
the tappet of the valve being adjusted is on the
heel of the cam, (ie opposite the peak). Turn
the engine until valve No 8 (nearest the
flywheel end of the engine) is fully open. With
the engine in this position, valve No 1 will be
fully closed and ready to be checked. On
manual transmission models, the engine can
be turned over quite easily by engaging top
gear and moving the car forwards. This should
only be done on level ground; and make sure
that the car cannot run away! An alternative
method, and the method that should be used
on automatic transmission models, is to press
the fan belt midway between the water pump
pulley and dynamo or alternator pulley and
then turn the fan blades.

What exactly does that mean?
If its saying what i think its saying ie/stop the belt turning the water pump pulley and alternator if i were changing the fan belt (as it needs changing) could i just remove that and simply rotate the fan to open and close the valves?

Or is there an easier Method?
I know they say rocking the car back and forth does the same on a Manual but its not the recomended proceedure for an auto

So Any ideas the easiest way to adjust them on an Automatic?

Huggz
Jodie

[MiniR2]

What the Haynes actually means is to apply pressure to the longest point of the fan belt and the rotate the engine via the alternator/fan blades.

What normally happens when you turn the belt via the alternator/fan blades is the belt just slips around the pulleys, due to the fricition between the belt and the pulley being less than the effort needed to overcome compression in the engine. By putting pressure on the belt, you increase the friction by making the belt tighter, so when you rotate the alternator pulley/fan blades, engine compression is overcome.

I personally wouldn't turn the engine using the fan as you could run the risk of snapping the blades off. I've found it works best to rotate the engine via the alternator pulley using a spanner(22mm iirc), or if you don't have a spanner big enough, you could carefully place a flat blade screwdriver between the vanes on the alternator and rotate it that way.

Turning the fan with the belt off would just rotate the water pump, as without the belt, the fan isn't directly connected to the engine

[kalkat]

What Minir2 says is very true. When I adjust the tappets on Vanessa, I take the sparkplugs out so there isn't any compression. If you do this, there is a fair chance you'll be able to turn the engine using the fan belt or spanner on the aalternator pulley. I wouldn't recommend using a screwdriver through the fan blades on the alternator though.

Emma

[asahartz]

I use two means to turn the engine over; I have a "remote starter" which is basically a switch that connects to the solenoid. It's tricky getting an exact position but it's close enough to get the valves in about the right place to adjust them (which basically means when there's no cam lift, so in the recommended positions the cam follower is opposite the cam lobe).
If I want it more exact I have a large spanner which fits the crank pulley bolt and I turn it with that. Being very careful of course to take it off before trying to start the engine!

[jockduck]

Gee you guys do things the hard way, there is a small hole in the converter housing so that you can engage a screwdriver on the starter ring teeth and "bar" the engine back or forward 1 tooth at a time. it could have a rubber bung in it( the hole that is)
When using the rule of 9 it is usualy possible to do two valves in each position so you only have to move the engine 4 times.

[kalkat]

Errmmm ...not necessarily the hard way, 'barring' the engine round is fine if it works for you. I don't do that 'cos it takes the paint off the torque converter housing and nadgers up the edge of the hole (plus I normally can't find my BIG screwdriver)

It's interesting to note you know of 'the rule of nine' and that you can do (usually) two valves at a time - mechanic by any chance?

Emma

[mollymoke]

Thanks for this post, I was thinking about this last night, hey I'm working away from home, no car for a week, just planning my next service, what else is there to put you to sleep
Anyway I also noted on my torque converter it has a ring of teeth that point out towards the cover, and these line up with a small (about 5/8") hole that is missing its cover I was thinking these may be used to lever the engine over, they don't look very strong, but if the plugs are out, no compression....

Mind you these may also be some cooling fins?

[niceboy1275]

Nov 6, 2009 11:44:03 GMT kalkat said:

Errmmm ...not necessarily the hard way, 'barring' the engine round is fine if it works for you. I don't do that 'cos it takes the paint off the torque converter housing and nadgers up the edge of the hole (plus I normally can't find my BIG screwdriver)

It's interesting to note you know of 'the rule of nine' and that you can do (usually) two valves at a time - mechanic by any chance?

Emma

The rule of 9 was how I was taught as well. And when I did Lil Egg's valve clearances we took the spark plugs out and turned the engine by the metal fan blades. barely any effort required and I could do the two valves at once. Took about 10 minutes to do the whole thing.