1300 - My first cambelt change (ever) : Checklist

[Modano]

Hi
I've been collecting info through books, tech data, forum topics and I wanted to share my thoughts and prepare my homework.
Sorry in advance for being detailed, but I'll do the job alone, and this will be my first cambelt change ever. I saw one with the previous owner 10 years ago.
The Tensioner part was taken from the book "Twin Cam Italia". Not sure about this procedure.

The engine is a 1300 828C3, car is on jacks, wheel removed.
I took the same cambelt reference as the last time it was done (10 years ago, 10 kms mileage), a Contitech CT651 (144 teeth).
I changed the tensioner bearing back in 2006 (QTT163 - Ext diam 67mm, width 26.5mm) but it shows sign of aging (superficial rust and grease coming out) - see pictures. The first point would be to ask myself : shall I change that (either the bearing or the whole assy), although I think this would be better.
Other info : the crank pulley is not removable. 2 different mechanics tried in the past, never were able to remove it. I certainly won't be, either.

I first took a bunch of pictures with crankshaft at TDC. All marks seem OK, all have existing white paint marks, although I think the Aux Shaft is one degree left as per the 34° and pictures, it seems the hole is rather on the centerside of the bearing plate nut, instead of being on the "left" part. (see pictures). You can also see the global wear of the belt. We can see micro cracks on the tensioner picture (maybe they won't show on the reduced sized pictures)


Now, the process.
-The alternator belt was removed.
-I removed the yellow cover
-Remove the spark plugs (car won't move, it is jacked)
- Remove the water pump pulley

In case I don't change the bearing/tensioner pulley :
- Release the tension (this is where I'm really not sure to understand). If we see picture (with labels 1-5) , my guess would be to unscrew a little bit "4", push the spring "2" with a hammer handle in order for the whole plate to "pivot to the left" so that the tensioner pulley loosens its tension, allowing for the removal of the cambelt. Then screw to block the spring in that position.

- Remove the old cambelt
- Fit the new one by starting on the crankshaft (remember I cannot remove the CS pulley), then the aux (minding not to move it), then the Tensioner, the Exhaust Cam and then finally the inlet (by "pressing the belt flat against the inlet cam wheel").
- Unscrew nut "4" so that the tensioner pulley will move towards its natural position (through the spring force), screw nut 4 again
- Perform a manual turn of the crankshaft, Unscrew Nut "4" again to release full force
- Perform two or more manual turns of the crankshaft to sense any blocking point. Check timing marks on all cams and Aux shaft.
- Screw nut "4" once for all
- Start engine and perform ignition timing

What do you think ?

[SanRemo78]

Once you've changed the belt remove the plugs and turn the engine over by hand (using a socket/drive on the crankshaft nut). That'll confirm that the pistons and valves aren't in contact and don't forget to tighten up the tensioner bolt once you're done. Just a caveat! It's been a while since I changed a belt!
Guy

[Modano]

Yes thanks.
Leaving the plugs only make sense if I remove the crankshaft pulley.
I’ll update my post

[peteracs]

Hi

On the crank pulley, ideally I would want to remove it. Makes the job much easier and less chance of damaging the belt. I have done it both ways, hence the comment. I used a rattle gun on a few engines and eventually the nut came loose. Depending on your engine you may need a reasonably high power one.

Peter

[Modano]

Hi

On the crank pulley, ideally I would want to remove it. Makes the job much easier and less chance of damaging the belt. I have done it both ways, hence the comment. I used a rattle gun on a few engines and eventually the nut came loose. Depending on your engine you may need a reasonably high power one.

Peter

Thanks.
I might check to borrow one or rent one then?… I guess it may add a little trickery if I don’t remove it (I guess you always need to pull the belt to make sure it’s inserted properly…
But I remember my mechanic told me he tried for a long time unsuccessfully , with all his experience and tools. I’m afraid this one is really Badly seized

[WestonTB]

Hi There,

Don't worry too much about the Aux pully moving out of line with the 1300 & 1600's, you will be fine if it moves, just aim for getting it spot on. It is only on the 2.0 that it is critical that the Aux pulley marks are 100% , it is also super easy to move the Aux pulley once the belt is off.

I would say replacement of the tensioner bearing is just a important as the belt change, to make life easier put the bearing ( from Mark@Betaboyz of course!) in the freezer for a few hours and the tensioner pulley in the oven (circa 200deg for approximately 10 min, I don't put salt & pepper on mine!!!) Sensible gloves and the very cold bearing will fall straight in no problems.

My crank pulley on my 2.0 is also 'fused' on but being an ex i.e engine there is loads of space to thread the belt round, look, move & check teeth located.

The Haynes manual is useful & any Guy Croft tips are excellent, trial & error are needed as is measure 10 times... cut once, don't rush, step by step, come back too the next day if necessary & no resistance should be felt when turning over with 38mm socket & plugs out, then and only then when you are happy give fuel & spark! 

[Modano]

Thanks.
So you advise to change the bearing alone (not the whole assembly), ie from this part : https://353652584127257704.weebly.com/store/p118/Cambelt_Tensioner_Bearing_All_Models.html (Do you know who manufactures this bearing ?)
I'll need to sandpaper the pulley as it has a couple of very light rust spot (at least aside the belt path). If I remember correctly (I hate my 10 years younger self for throwing the old one) the pulley is maintained with a simple circlip.

PS: I'm still unsure about the releasing of the tensioner pulley spring (well, unsure about everything related to this pulley), see my first post about which steps to release the tension

[Nigel]

Hi Modano,
That is the correct bearing as listed.

You can use a large screwdriver or pry-bar to let off the tension.
It's not too difficult.

Hope this helps and good luck,

Nigel

[WestonTB]

Hi Modano,

The bearing is SKF, Mark always has the right ones at the right price. You are right, getting the tensioner right does involve a bit of spanner twiddling! Eric Weston & HF Stuart are the aces at this but as I see it you do of course have to undo the M10 (I think?!) 17mm nut to remove the tensioner bearing/ pulley assembly which can be tight ish' against the inner wing, then also loosen but do not remove the 13mm M8 shaped/contoured bolt ,no3 on your image, also loosen the 13mm M8 bolt & do not remove it ( no4 on your image)

Careful prying with a strong flat bladed screwdriver will release the spring from the backing plate, be careful not to catch/lean on any bits of distributor/wiring etc, with new tensioner bearing/pulley assembly back on I put the spring back in place, nip up the 13mm bolts (but do not tighten fully) , then with strong flat bladed screw driver add tension to the pulley and locate/lock in place with the 17mm locknut (no5 in your image)

Then when happy with tension fully tighten the 13mm bolts & start the measuring 10 times cutting once procedure of turning over with 38mm socket before adding spark & fuel.

It goes without saying to make sure you are happy with bolt no 5 (17mm one) is locating its stepped washer properly in the centre of the bearing and every thing turns as it should.

Enjoy ! 

[HFStuart]

It's been a while since I've done one but I think you can leave bolt 4 alone. Crack bolt 3 undone slightly and loosen nut 5 a couple of turns. Turn the engine over by hand a couple of times like that and then nip up bolt 5 and bolt 3. Check the timing marks (it should be fine) and you should find the belt tension is about right without having to lever the tensioner pulley about  - the spring is supposed to do the work.

Assuming all is well torque the bolts up and you're good to go.

[Modano]

Hi
sorry for not boucing back. The temperatures were a bit low in the garage and had a couple of other things to sort out.

How would you remove the old belt ? Cut it ? Remove it after loosening the tensioner ? I guess it's better to cut it instead of removing and perhaps move one element.

Also I removed the three screws holding the water pulley to make room. I couldn't fully remove the pulley, cannot extract it as it seems captive around the inner wing, but I could make a bit more room.

[Nigel]

Modano,

You can create more room to remove the water pump pulley by
dropping the engine down a little. Do this by slackening the 4 subframe
bolts, the 2 engine side by around an inch. This should get it past the chassis rail.
But all of that is not absolutely necessary.

From TDC, slacken no3 and no5, as already said, keeping a 17mm spanner on no5.
Using your pry bar/screwdriver/whatever, release the belt tension then re-tighten no5,
keeping it in the 'slack' position. You can now remove the belt anyway you like.

You will have to introduce the belt to the crank pulley by the flat to get it past
the fixed stone guard. After that, as said above, the last pulley is the inlet, after checking
around a million times that all your timing marks are correct.

I tried not to repeat the other good advice above, but probably did.

Hope this adds, and not confuses more.

Nigel

[Modano]

I'm back on this topic.
Thanks to all.

Got the proper 38 wrench to rotate the engine, the circlip tool.

So, I unscrewed the pulley bolt N°5 (13), the N°3 (17), and I could manage to move the pulley assembly a couple of mms to the bottom, by hand.
Currently, I haven't found a "safe" tool that would allow me to release the pressure without, as someone said, risking to slip and damage myself of nearby components.

Is taking the spring out (with proper pliers) carefully, because I imagine it will hit back rather violently towards the distributor cap, a possibility ? I think that it may allow full release of the tension, avoiding further headaches because I couldn't manage to release enough to fit the new belt.
Maybe it will be very difficult to put the spring back.

Otherwise, remember that I need to change the bearing. Is it possible to remove the bearing and pulley assembly with the backing plate in situ ?
The oven and freezer is for fitting the bearing in the pulley, any problem to face to separate them and to remove them from the plate ?

[Modano]

Hello
to sum up after a couple of extra readings across the internet :
Is there any risk to remove the spring end from its location ? Will a single person enough to put it back with pliers ? Any risk that given its force it will hit the dizzy cap ?
I'm ready

[Nigel]

You will not get any violent movement from the spring.
Its static state is safe.
Go ahead and remove as required.

Hope this reassures you.

Nigel

[SanRemo78]

I've still got the 15 inch spanner I always used.... First application was for starting a Fiat 126 with a stretched cable and i kept it in the toolbox for years.
The shaft is thin enough to slip between the tensioner bracket and it's spring, inserting it beyond the lower slotted clamp bolt and then take the tension out of spring and move it sideways out of hole in the bracket and then let the spring tension go. Refitting is the reverse procedure in good old Haynes Manual terms.
Must go dig it out, I'll need it again soon!
Guy

[Modano]

Thanks a lot.
Removed the old pulley … but not starting well

I tried the bearing in freezer for a couple of hours and pulley in oven (it was at 150 deg Celsius) to ease the assembly , but it was either not hot enough or I inserted it a bit unaligned , but obviously now it cannot be separated …. I’d like to avoid damaging it

What would you do ?

[peteracs]

Hi

Looks misaligned from the photo angle.

Personally I would put it in a hydraulic press to get the bearing out to start again.  Remember to press the out race and not just the inner or you will damage the bearing. Ideally use the press to put the bearing in as well.

Peter

[Modano]

Yes you’re right, totally misaligned… but it is a one try process   as you say I don’t think there are any safe DIY options that may not damage (hammer etc) the bearing ..

[Modano]

I managed to push it gently with a 36” socket that fit the outer ring