Timing Belt and Cam Sprocket...

[casanis]

Just a quick question:

I am wondering how to remove the camshaft sprocket from a 1.6NA? I’ve loosened the bolt off a little (using a sprocket holder tool), but the sprocket is on there good. My pullers cannot get in behind and I’m hesitant to whack it with a hammer etc…This is my first diesel timing adventure…

I had my leaking injection pump rebuilt by Giles, Before removing it, I placed the engine in TDC (as per flywheel mark), however, in order to get the cam lock in place I had to move the camshaft a little. With that said, my flywheel has moved about 1cm from the 0 degree TDC mark. Pump was then removed and Giles preformed his magic. I took this opportunity to replace the water pump/housing, hoses, t-stat, power steering, AC and Alternator v-belts, glowplugs etc… I did not have to remove the timing belt as it is in great shape.

I am at the point of putting the IP back on, but cannot get the timing belt back on with it. It seems too tight. I am trying to follow vincentwaldens write-up. I believe my next step is to loosen cam sprocket so it is free of camshaft, and rotate the engine by hand until the flywheel TDC mark lines up, put on the timing belt (hopefully easier with loose cam sprocket?), tighten cam sprocket down, tighten tensioner, and then time the IP.

Can anyone offer some insight or words of wisdom?

Many Thanks!

[lovinthedeez]

rubber mallet and a big screwdriver. 



I don't loosen the cam gear (I know, I know ), but this is how I like to do it, and things always stay dead on.  I put the belt around the crank sprocket first to get a good tdc reading there.  Then I go around the tensioner and get the cam, which is already locked at tdc.  then I take an adjustable wrench or clamp or whatever ya got, and clamp the belt onto the cam sprocket.  now those two are in time together.  Then I pull the belt about halfway off the sprockets to get some working room and manhandle the belt over the pump sprocket.  I rarely have the crank "walk" on me whilst trying to get that darn belt on anymore.  

[Vincent Waldon]

As counterpoint, I'd kinda a "you must loosen the sprocket or god will kill baby kittens" kinda guy.  

 In my mind without the sprocket loose you are:

a) hoping the last guy/gal found cam TDC exactly right
b) not allowing an easy place for the belt to tension... which means something else is likely to move as you tighten the belt... most often TDC on the engine, since it's not pinned.

Pulling the sprocket also makes it super duper easy to slide the new belt on.

There are several ways to remove the sprocket:

- some people have good luck using a drift thru the access hole at the back to knock the sprocket
- a big 3-jawed puller  (this one works for me every time).

Just my personal opinion,

Vince

[Baron VonZeppelin]

There should be an open bolt hole in the metal backing plate for the timing cover - right behind the cam sprocket.

Slip a bolt in through the hole against the cam sprocket - and whack the bolt with a hammer, maybe a couple times.

Once you get it free, you'll need to remove it from cam - and install belt around sprocket - then install sprocket with the belt on it - back onto camshaft.

Leave the cam sprocket "semi loose" so it can rotate without effecting camshaft. Tightening that bolt is later in the proceedure.

Best is to also have the cam lock slide shimmed tight with a wide blade putty knife or feeler gauges on both ends - to get it centered and tight fitting on the slide bar.

*With all coordinates locked/set - but cam sprocket still loose.
Set tension on the belt by rolling the tensioner upwards/clockwise.
Just about hand/wrist snug.

*After tensioner is tightened - THEN you can tighten the cam bolt.

*Unlock everything.

*Rotate engine a couple/few revolutions by hand tool to check for no binding - strike belt with a rubber mallet or butt end of a hammer handle a few times in mid point between cam and inj pump to displace flex - and check belt tension with a gauge tool or the 45* degree flex method.

IF you need to re-adjust belt tension - put all your parameters back inline - lock it all back down - loosen cam sprocket bolt a bit and pop sprocket loose - then re-adjust tensioner.

Then go back through all the above steps marked with (*).

Once all that is settled - you can proceed with timing the inj pump using your dial indicator as described by Vincent in his tutorial.

I have the belt tension measuring tool. 12-13 units does NOT require you to put your elbow and arm into tightening the tensioner.
Which is what you would think should be necessary to get it "tight enough".
Just hand-wrist rolled up snuglly on the tight side. If your bicep flexes more than a twinkle - its probly too tight.

Vince was so slack about his write up.
He should have made it an all-inclusive write up for start to finish belt replacement proceedures, and web-hosted a comprehensive video start to finish.
And offered free loaner tools.
And send us all a Christmas card in December.

But the guy is Canadian after all ....  

okay most of those remarks about Vince were just joking, but he really is Canadian.

[Baron VonZeppelin]

we could get by with less kittens

they don't even taste good

[Baron VonZeppelin]

oh yeh,

when you mount the Inj Pump - get the raised line (reference marker) on the snout of pump - aligned with the indented mark (reference marker) on the metal backing plate of timing cover.

If you don't - and you have to adjust the pump wildly to get the right dial indicator reading - you can/will also compromise the belt tension spec.

And then you get to go back through that medley again.

And even recheck injection timing again afterwards with dial indicator .... again.

or maybe i'm just overly pissamistic about stuffs  

[Vincent Waldon]

we could get by with less kittens

they don't even taste good

Hmmm.  That's strange... 'cause as far as I know they taste, as does everything else in the Matrix, like chicken. 



Sorry OP.   

[casanis]

Wow - thanks for the great information everyone!

I will try the drift behind the access hole method this evening.

many thanks!

[Quantum TD]

Wow - thanks for the great information everyone!

I will try the drift behind the access hole method this evening.

many thanks!

I've tried that trick on the MK2 cam sprockets before. It's never really worked for me. It usually just puts a nasty dent in the back of the cam sprocket. I usually remove the camshaft bolt completely, and then slap the backside of the timing cover behind the sprocket with a rubber mallet, or a framing hammer if that doesn't work. A few clean whacks usually pops the sprocket off with no damage, and the timing cover usually sees no damage (since it's so close the cam sprocket anyways).

Key points though: COMPLETELY remove the bolt, and have your hand or a rag ready to catch the sprocket.

[Baron VonZeppelin]

We also forgot to tell you that its easy/possible to get the injection pump 180* degrees out of synch when starting from scratch the first time.

There is an index mark on the sprocket.
And another reference is the keyway location pointing back towards the engine - when at #1 with lock in place.
Let us know if you have any trouble, or success.

For reference in the future - always get the cam sprocket loosened from the cam as step #1. There have been a few times where i had to rotate cam and make strikes with bolt in more than one spot. But when it does pop loose - you just tighten'er back up and go back to your parameter. Then it pops off easy after the initial knock-off has been done - with one whack.

I realize you don't have that luxury in your current position.

If all else fails - you may need to remove the cam and get the sprocket off - since you can't do much cam rotating and your puller doesn't cooperate.

[Settings]

Great thread. Summarizes several related steps very well.
Should be stickied or FAQed.

My $0.02

[Mark(The Miser)UK]

Just like to add my £0.02 equiv worth re loosening cam sprocket...

1) Don't bother with a rubber mallet, you are making life hard. Use a flat faced steel one. A lead one is better than rubber.

2) Strike from the back. Don't use a bolt, you don't want point impact, but area. I'm assuming backing plate is like that on a Quantum. Strike through the back plate,after loosening bolt a couple of turns AND loosening the TWO Allen headed bolts that clamp the plate to the head, WHILST squeezing the plate with your free hand, against the sprocket. This will spread the blow.

3) Loosening the cam bolt without taking it off saves sprocket falling to the floor and hitting something hard...

4) To loosen the cam bolt DO NOT use your locking  bar.
Lucky people get away with it , but, "Are you feeling lucky{punk}?"
With cam free, but with belt still on, strike a sharp blow on a 19mm/3/4" wrench

[maxfax]

we could get by with less kittens

they don't even taste good

Hmmm.  That's strange... 'cause as far as I know they taste, as does everything else in the Matrix, like chicken. 

Sorry OP.   

Soy sauce... Lots and lots of soy sauce.... 

[Quantum TD]

Just like to add my £0.02 equiv worth re loosening cam sprocket...



2) Strike from the back. Don't use a bolt, you don't want point impact, but area. I'm assuming backing plate is like that on a Quantum. Strike through the back plate,after loosening bolt a couple of turns AND loosening the TWO Allen headed bolts that clamp the plate to the head, WHILST squeezing the plate with your free hand, against the sprocket. This will spread the blow.

3) Loosening the cam bolt without taking it off saves sprocket falling to the floor and hitting something hard...

Bad idea Papi. I tried that $hit once. Loosened the cam bolt about 1 inch, left it in place to prevent it from flying. I hit the cam sprocket and it pulled the nose clean off my camshaft. REMOVE THE BOLT.

[Baron VonZeppelin]

Hmmm.  That's strange... 'cause as far as I know they taste, as does everything else in the Matrix, like chicken. 

Sorry OP.   

Soy sauce... Lots and lots of soy sauce.... 

Grampaw told me i shoulda cooked that lil runt some first, but i was too hungry to wait.

soy sauce makes Perfect Sense too ... tyvm Max