How Many Teeth Can Your Timing Belt Skip Before Crunch?

[webber]

Hey guys, we just brought in an R32 GTR fitted with an N1 engine for race.

When it turned up it had a blown turbo, which we just replaced, and we are going to change the timing belt. Now we have a Nissan flywheel lock-up tool, but lost/misplaced it, so we tried locking up the cam gears (and relying on the belt to hold to undo the crankshaft bolt.

It jumped 2-4 teeth. No crunches or locking or anything.

Just wondering how many it can jump before CRUNCH!

Cheers

[Adriano]

I would just refit the timing belt correctly, then do a comp test. The easiest way to undo the crank bolt is to put a breaker bar on the crank bolt and crank the motor. Or stick it in 4th with the handbrake on tight.

[Adriano]

Also there is about a 50% chance the engine is damaged from the blown turbo.

[Cartman]

its amazing how many people dont relise you can just get a long breaker bar stick it on the bolt and up against the chassie and crank she comes undone!

[Moodles2]

That's exactly how my mechanic undid my harmonic balancer bolt, my starter motor plus a big bmw 900 CCA battery

[The Dan]

You guys have obviously never undone the balancer bolt on a 32 GTR before.

Yes it may work 1 / 10 times. The rest you need a special tool and a big hammer and smash away at it for a half hour or a 3/4 inch rattle gun and remove the aircon.

If it's been off before, then it is usually easier to get undone.

And NEVER EVER EVER suggest putting the car in gear with the handbrake on and undoing it that way. With a 1m breaker bar you can create more torque than your engine can produce and then say goodbye to your gearbox.

I've seen it happen a couple of times by mechanics I used to work with. It does happen and it happens very easily.

[johnnyt]

You guys have obviously never undone the balancer bolt on a 32 GTR before.

Yes it may work 1 / 10 times. The rest you need a special tool and a big hammer and smash away at it for a half hour or a 3/4 inch rattle gun and remove the aircon.

If it's been off before, then it is usually easier to get undone.

And NEVER EVER EVER suggest putting the car in gear with the handbrake on and undoing it that way. With a 1m breaker bar you can create more torque than your engine can produce and then say goodbye to your gearbox.

I've seen it happen a couple of times by mechanics I used to work with. It does happen and it happens very easily.

Just curious.. what is your suggestions for tightening it? without taking the aircon out and using a 3/4 inch gun?

[IanB]

According to godzilla, my cars timing belt was two teeth out retarded and my motor is now fine with a new timing belt on.

Regards

Ian

[jase-r34]

Dear god who would put the car in gear with the handbrake on and crank it over to undo the harmonic balancer bolt???

I have undone heaps of balancer bolts (none on skylines though) and most of the time I've used the breaker bar and wedged it with a rag into the chassis somewhere. But in neutral! Why on earth would you put it in gear??

[The Dan]

Just curious.. what is your suggestions for tightening it? without taking the aircon out and using a 3/4 inch gun?

Use a tool called a Power-bar. It is available from Repco, made by ABW and costs around $140.

Will undo and do up. GTR's are a flamin mongrel of a thing and 32's being the worst, can take some hammering before they budge. Have only had to pull back the a/c twice before but if it's been a dockside ornament for a while then the rust can set in.

[The Dan]

Dear god who would put the car in gear with the handbrake on and crank it over to undo the harmonic balancer bolt???

I have undone heaps of balancer bolts (none on skylines though) and most of the time I've used the breaker bar and wedged it with a rag into the chassis somewhere. But in neutral! Why on earth would you put it in gear??

The reasoning is to stop the engine from turning over - or at least attempt to...and manually turn the breaker bar to undo the nut

Nothing wrong with putting the breaker bar under the driver's side (for right hand drive cars) chassis rail and flicking the key. Have done it that way many times with great success. It's doing it back up that the Power-bar comes in handy

[ahh 33 s2]

yeh my 32 gtr bolt took several blasts with the rattle gun to get it off.. almost gave up on it

[89CAL]

or the car cranks, u slip off the bar and it damages radiator surrounding components

having the car in a high gear with the handbrake on should be plenty fine. Not saying cranking the engine doesnt work, but id hate for someone to go 'yeah that'll make it way easier' and go and crank their breaker bar into the side of their engine bay

[Adriano]

If you have a long enough bar, then there is no way it can damage anything.

[The Dan]

or the car cranks, u slip off the bar and it damages radiator surrounding components

having the car in a high gear with the handbrake on should be plenty fine. Not saying cranking the engine doesnt work, but id hate for someone to go 'yeah that'll make it way easier' and go and crank their breaker bar into the side of their engine bay

The bar can't come around the engine bay if it's under the chassis rail.

Try it the other way at your own risk. Don't say you weren't warned though.

I still advise using the Power-bar over the breaker bar under the chassis rail method but when you don't have the tool, then that's the next best way of doing it without damaging anything.

If you have a long enough bar, then there is no way it can damage anything.

Exactly. It's not a breaker bar unless it's at least 1m long

[Moodles2]

From what I understand out the factory the harmonic balancer nut is torqued to about 150nm, if your skyline ever had it's harmonic balancer bolt undone (like for a 100,000km service to do the timing belt) at a Nissan dealership in japan, they torqued the balancer nut to approx. 500nm.. in my case was about 460nm.

[GT-RZ]

From what I understand out the factory the harmonic balancer nut is torqued to about 150nm, if your skyline ever had it's harmonic balancer bolt undone (like for a 100,000km service to do the timing belt) at a Nissan dealership in japan, they torqued the balancer nut to approx. 500nm.. in my case was about 460nm.

harmonic balancer tightened to 460nm...?