Crank bolt. Cambelt change.

[ElanBRG]

What Giniw said.

That's how impact wrenches work. It's just a matter of having one powerful enough with a good air supply, and that bolt is coming off without any turning of the engine. Definitely the best way to do it.

[Simon_P]

I've had one with a breaker bar loaded up by a lorry mechanic and a large impact wrench driven by a 100 litre compressor.

Said lorry mechanic made up my bar out of 1/4 steel bar, tickled the bolt with the gas spanners, then offered it some advice.

I've kept the bar and the job is now always fairly easy. The bar is also useful for tightening the bolt. I don't let the lorry mechanic do things up though as he only has one torque setting... FT!
I'm happy to lend the bar to anyone who doesn't have access to a compressor, impact wrench, or lorry mechanic.

[Edward]

Apologies for resurrecting such an old thread. I've been searching for some info as I'm just about to do an engine change but thought that I'd do the cambelt on the replacement engine prior to putting it in the car.
I've not got loads of experience but I've successfully just done the camblet on my old Ford Puma. On that, I locked the flywheel using a special tool so when I hung off the camshaft pulley bolt with a breaker bar and jack handle to undo it, nothing moved anywhere. And that was ridiculously tight to undo/do up.
My query is, if I make a tool that holds the pulley itself to stop it turning, won't the rest of the engine try to turn via the camshaft when applying force to the bolt and possibly bend the bolts holding the camshafts at TDC when applying pressure? Or, as I'm writing, and my brain is computing it all a little bit, does the Woodruff key on the pulley then stop the crankshaft trying to turn because the pulley is locked?
Any advice on doing the cambelt out of the car gratefully received as most seems focussed on doing it with the engine in the car. The flywheel and gearbox are also off the engine as I'm going to swap these from my existing engine (and suffer the minor crunch on second that) so can't lock up via these unless I swap these prior to doing the cambelt. Which I can do I suppose!
Yes, advice definitely needed or I'll just make it up as go. I've watched the two youtube videos on cambelts being done in the car and it doesn't look like the crankshaft has been locked at all - particularly with the one that is taken off with an impact driver (Tuga's one?). Does the old belt tolerate that as I have access to a decent impact gun and then I wouldn't have to make a tool to hold the pulley.....
Many thanks in advance,
Edward.

[Tuga2112]

my impact driver is 1050 with 1700nm. breakaway (accoding to their website. but the advertised figure in machine mart was 2100nm when i ordered it)
The same impact driver done the NA crankshaft pulley with equal ease. and that one was torqued by PNM themselfs 2 years earlier

the standard/common impact wrenches are 720nm with 850 breakaway.

just because it looks easy, it doesnt mean its loose

try getting hold of a impact wrench that strong and see what results you have... just remmeber those are on the £300 price benchmark

[Fredjohn]

When replacing cambelt, the workshop manual recommends using 2 of the bolts that hold on the plastic cover to hold the cam pulleys in place. There are 2 tapped holes in the head that line up with holes in the pulleys, and are the same thread as the bolts.

Provided you don't turn the crankshaft once the cam belt is off, everything will stay in the correct relative positions.

Remove fan belt pulley first then reposition to TDC afterwards (if necessary) and lock up cam pulleys with the 2 bolts. Then proceed with cam belt removal.
Workshop manual is available on this forum.

[dapinky]

Edward,

The 2 bolts through the camshaft pulleys will hold the whole thing in the correct position using M6 bolts from the cam cover (or spare ones!) - BUT - they wouldn't be suitable to hold the mechanism in place when undoing the crank pulley bolt. There is so much force applied (either with an ugga-dugga gun or a lever) that it is likely to turn the pulley with enough force transmitted through the belt to either break the belt of bend the 3 locating bolts.

The crank needs to be held in place to prevent it turning. I have never had a problem with the engine out of the car, and it is often easier as you can get to the bolt to apply the correct force without having to use various extension bars.

I use a steel bar bolted to the pulley (2 x M6 threaded holes, one each side of the bolt) with a hole for the socket to go through. With the engine on a low stand, it will fit and jam against the floor to prevent further rotation. Obviously, the engine needs to be steady and not allowed to flip over!

I am sure that it would be possible to fabricate a bar that attaches to the pulley as described, but then has a hole a short distance out that you can put a suitable locking bar (I'm thinking an M12 suspension bolt, or whatever) so that it jams against the block to prevent further rotation.

Jamming the other end of the crank should also be possible, using the bolt holes for the flywheel to hold a suitable bar?

Whichever way you decide, I think you will need to hold the actual pulley or crank and not rely on the belt and camshaft pulleys to keep it all in place.

[Giniw]

Quite frankly an impact wrench is SO useful it should be bought almost before a screwdriver.
If you have a compressor it's not even that expensive, mine is a KS Tools monster 1690Nm, it was listed at 150€ but got it for 126€ with a coupon on amazon in 2015, it's currently listed there at 160€ and with a bit of patience you might have it a bit cheaper.
Of course it implies you have a compressor, which is also a good investment, and a small one is not that expensive either (useful for a loooot of things)
Now, if can't have a compressor (lack of space etc), I suggest you take a look at electric impact wrench, apparently they are quite powerful. But I'm not too sure about the price.

But really, an impact wrench is a must.
- Crank bolt? Easy. I was disappointed it was not a challenge for the wrench when I did the cambelt the second time.
- Hub nuts? Easy too, you do it with the wheels in the air
- also it's nice to not lose time when you remove the wheels (I would not recommend the investment just to change a wheel though)
- etc.


PS: by the way I've used the first low power position all the time to unbolt anything (including the crank pulley, etc).
I've used the max power only once to try to remove a seized bolt from something. I was holding the part in a small vice and ... it broke the vice (would not recommend then, it was a bit stupid)
And that is with an air supply a bit on the low side (pressure drop so an effective pressure of about 5.5 bars maybe, instead of about 6.4 bars. And that makes a big difference, you can hear it very well.