NA8 Timing Belt Change Progress Report .. and some questions

snshami · Postby **snshami** » Mon May 28, 2012 1:59 am

The timing belt project has been going for around 5 hours and I now have the cam sprockets off the crank pulley. I can see the crank sprocket but can't take the belt off like on early cars because the cam sprocket has a disc covering it (NA8). The disc is just large enough to prevent the belt coming off. The next job (tomorrow is the water pump) Are there any special tricks with this.

I have locked the crank to the alternator pivot in preparation for removing the crank bolt.

I have also taken the sparks plugs out to make turn the cams a bit easier when its time to adjust them.

I have a question about the cam sprocket bolts. They were a real pain to get off and required a lot of force with a breaker bar (while my son held a wrench on the camshaft with a pipe extension) not just to break the clamp load but for most of their thread travel. It was almost like someone had used thread locker. Is this normal. In youtube videos it seems so easy. I am now dreading removing the crankshaft bolt.

JBT · Postby **JBT** » Mon May 28, 2012 8:49 am

They normally come out easy like any machine bolt. Maybe someone has been in there before and put thread locker on them

Postby **NitroDann** » Mon May 28, 2012 8:49 am

The use of threadlocker is normal, I recomend its use on the crank bolt at least.

The water pump is a walk in the park.
Just clean the sealing surface thoroughly with a razor/scraper before fitting the new gasket and pump.

Dann

JBT · Postby **JBT** » Mon May 28, 2012 9:26 am

NitroDann wrote:The use of threadlocker is normal...

Not by the factory on the cam sprocket bolts.

project.r.racing · Postby **project.r.racing** » Mon May 28, 2012 9:44 am

I'm assuming the OP is talking about the pulley boss preventing him/her removing the belt. The belt will come over this boss if the tension on the belt is released. ie- Undo the tensioner and move it to the left as far as possible.

Postby **NitroDann** » Mon May 28, 2012 9:54 am

Or remove the cam gears.

As for threadlock, correct, none used at the factory.

Dann

droo · Postby **droo** » Mon May 28, 2012 10:38 am

I ended up getting a length of steel with a cut out for the crank pulley cover and two holes either side of the cut out (bolting into 2 of the 4 bolt holes in the crank pulley cover). That was used to wedge against the ground while i used a breaker bar w/extension to undo the crank bolt. It was very easy that way.

The length of steel cost me $10 to get an engineering shop to make and looks like this:
http://www.flyinmiata.com/index.php?dep ... 000%20%20P

It also works in reverse - being able to tighten up the crank bolt VERY easily.

I'd strongly recommend getting this to make your life easier.
It's been said to have the car in 5th gear and have someone press on the brakes while the crank bolt is undone/tightened but that's also putting a decent load of stress on the entire drive train - which the system should handle but makes me uncomfortable.

ALSO, once you've got the crank cover thingy and bolt off the crank itself - i've made this video to make fitting the timing belt VERY easily.

http://www.youtube.com/watch?v=pOOUIwSlF8A
*shameless plug*

Keep us posted!

snshami · Postby **snshami** » Mon May 28, 2012 11:46 am

JBT wrote:They normally come out easy like any machine bolt. Maybe someone has been in there before and put thread locker on them

There was some red stuff when I took the cam sprocket bolt off, which I am assuming is loctite. Do I need to loctite them when I reassemble.

JBT · Postby **JBT** » Mon May 28, 2012 1:46 pm

It's generally worthwhile using a little bit of thread locker to ensure things stay assembled.

snshami · Postby **snshami** » Mon May 28, 2012 2:11 pm

Thanks for all the replies so far. You might not realise it but your support helps a great deal. I do have one more question. I rounded the head off one of the small bolts that holds the crank pulley. The bolt has the number 10 on it. Any thoughts on what to replace it with and where to get them from.

Should I try a pickapart or would a Mazda or Ford dealer stock them ? can I use any 8.8 bolt with the right thread.

Mr Morlock · Postby **Mr Morlock** » Mon May 28, 2012 2:31 pm

You will be able to buy it from Mazda- low cost item but you get the right spec and plating. Other options is a proper fastener supplier - most areas have a supplier in reasonable proximity to where you work or on the way etc- not Bunnings who are in a different market. Take the bolt with you if not getting it from Mazda so that the bolt supplier can quickly check the thread / pitch/ diameter and grade. The 10 is as far as I know the grade to the relavant standard and may be higher tensile strength than 8 - do not take that as fact.

snshami · Postby **snshami** » Mon May 28, 2012 2:38 pm

NitroDann wrote:The use of threadlocker is normal, I recomend its use on the crank bolt at least.

The water pump is a walk in the park.
Just clean the sealing surface thoroughly with a razor/scraper before fitting the new gasket and pump.

Dann

The front bolts look easy but how about the two for the inlet. There seem very little room to undo them. Is there a need to remove the PS pump.

ak_perth · Postby **ak_perth** » Mon May 28, 2012 2:56 pm

Hi snshami,

Sorry, i have no knowledge of what you are doing and can offer no advice, but i am following your thread with interest and i just wanted to pitch in and wish you luck! :beer:

Cheers

AK

snshami · Postby **snshami** » Mon May 28, 2012 3:20 pm

Thanks !
Once its all done. I'll put everything together in my garage section

snshami · Postby **snshami** » Mon May 28, 2012 3:26 pm

snshami wrote:Thanks for all the replies so far. You might not realise it but your support helps a great deal. I do have one more question. I rounded the head off one of the small bolts that holds the crank pulley. The bolt has the number 10 on it. Any thoughts on what to replace it with and where to get them from.

Should I try a pickapart or would a Mazda or Ford dealer stock them ? can I use any 8.8 bolt with the right thread.

Just got a quote from the friendly Ford dealer for Laser TX3 bolts (they should be the same 'cos they are the same family of engine) for $14 for four. I think I'll first try pickapart tomorrow. There is one near work. I forgot my gloves today.