[Vwdiesel] changing the timing belt

[Sandy Cameron]

At 10:04 AM 24/12/2006 -0500, you wrote:

Once I adjusted the tensioner though things
>> shifted just a bit.
>>
>> Now with the crank at TDC the slot at the back of the camshaft isn't
>> quite parallel to the head - it looks to be a hair advanced, maybe 2 or
>> 3 degrees.  Also, the IP is a hair advanced - more like half a tooth's
>> worth, as it seemed I could either have put the belt on where it was
>> half a tooth retarded or half a tooth advanced, no in between.  How
>> close do I need to have these set for the engine to be able to operate
>> reliably, or should I say optimally?  Should I take the cam-sprocket
>> lose and realign?  I haven't run it any yet, other than to turn it over
>> by hand to see if things shift any more (it didn't).

The cam sprocket on the 1.6 diesel does not have a key. There is a slot on
the camshaft for a woodruffe key, but not inside the sprocket. There for, NO
KEY AT ALL in the cam shaft.

It is a friction drive.

There is a key for the inj. pump, and I've never had an intermediate shaft
pulley off, so don't know about that.

If you put a key in the camshaft, that's where youre problems started....it
will be crooked, it wont work, may slip and trash the engine, etc.

The surface of the tapered end of the camshaft must be squeeky clean (I use
brake cleaner)
No trace of oil or grease allowed. Same for the tapered bore of the sprocket.

If the inside of the (cast iron) sprocket bore is slick and shiny, you might
want to de-glaze it a bit with fine emery cloth.

With the engine at TDC, and a parallel bar in the slot at the back end of
the cam, slip the sprocket, belt, and tensioner in to place (you did lock
the pump sprocket with a bar, and the sprocket mark notch up?)

It goes together easily if you slip the sprocket on the shaft loosely, and
the belt and tensioner, all at the same time (easy for me to say)

After you get it together, you can replace the cam bolt, but do not tighten
it yet, let the sprocket be a little  loose on the shaft.

Check TDC, Pump lock, and parallel bar on the camshaft again, that all are
where they should be (if not, fix it.) 
Now snug up the tensioner a bit to remove any slack from the belt, rock the
engine a tiny bit to seat the ribs in the notches (Buenos)

Only after everything is properly seated, prepare to tighten the cam
sprocket bolt.

You must use some kind of reactive leverage on the sprocket to tighten the bolt.

I made a gizmo about 2 feet long out of 2 angle irons bolted together at one
end in the shape of a long "V", and 2 bolts thru the other ends that extend
far enough to engage the holes in the sprocket. I use this apparatus to
reverse torque the sprocket while wrenching the bolt, both for tightening
and loosening

This ensures no torque will be applied to the belt, or the slot in the other
end of the cam, which , I 'm told, will snap off if levered against.

Works for me.

Sandy