The MGF Register Forums

The chances of both snapping simultaneously are I suspect close to nil, but if one bolt snaps the other is henceforth operating in the extremes of its abilities. The fracture point is at the very beginning of the thread, there will be a little galvanic corrosion on the shank but not enough to lock it against the alloy so a snapped bolt is easily detected - it won't be finger loose but will turn as soon as light torque is applied. If you make that check part of your routine servicing regime, you'll never be sorry

Unfortunately some mechanics are way too fond of the windy gun for tightening bolts.
Funnily enough the only bolt I had trouble with during my recent HG/Timing Belt change was the
8mm Allen bolt on the manual tensioner. It must have been over 100nm. I was glad I had the proper
bit and a long breaker bar. If it had stripped I would have been in big trouble!

[quote="S67SOK"]Crank pully bolt whizzed out with my air gun, just in gear with the handbrake on.

quote]


The idea of locking the crank in place while the cam belt is disconnected does appeal to me. If it's all bolted up tight
and cannot move then there would seem to be zero risk of getting the cam timing wrong. And getting the starter motor out is not THAT hard. Am I being over cautious or is the crank locking tool a worthwhile investment.

Also when I'm ripping the head off do I need to lock everything first or just drain the coolant and unbolt everything?
Might be good practice though? Obviously head replacement is a different story.
On 2nd thought I'll read the manual and see what it suggests.

Hi Robbo,

the crank locking tool is a good invest if you haven't got an air gun or any other power tool capable of - say - 300 Nm torque. I have taken out a number of starter motors and you're right, it's not that hard after all. But I wouldn't lock the flywheel and thus the crank during operation. There are quite straightforward marks on the crankshaft and the engine block for timing purposes and also after fitting the new cam belt you have to turn over the engine a couple of times to assure the timing is indeed right. Usually, I leave the locking tool in place, I just remove the top bolt so it can be swung out of the way. It is then easily back to function when the crankshaft pulley is to be refitted.

As to "heads off" I would suggest to keep the cam locking tool in place at first. If the mating surface turns out to be okay, it's one less thing to care about. When the head has to be skimmed, everything has to come off anyway.

If there is no sign of mayo (requiring the coolant system do be flushed) I don't drain the coolant, I just remove the water pump first and then the coolant level will be below the cylinder head anyway. After everything is fitted again, I simply top up with clean water and bleed, then give the car a good run to check for leaks/overheating. If everything's fine, the coolant will be completely replaced.

hth
Mykel

So it's 5-1/2 years later and I'm experiencing the joy of refitting a cam belt in situ.

And I'm having all the trouble of these previous posts. I ended up removing the crank pulley,
nesting it in the belt and gently knocking the pulley back on.

THIS TURNED OUT TO BE A REALLY BAD IDEA.

as the belt went on one tooth out. If the belt won't go on with just using your fingers
then something has moved and it's no longer perfectly lined up. I might try loosening the
crank locking tool and nudging the crank around a few degrees to get the tension on the exhaust side belt run.

Now that I sit and type, I realize removing the crank pulley to get at the oil seal takes the tension
out of the exhaust belt run and made the belt all but impossible to slide over the tensioner.
also the crank locking tool was not locking the crank up totally and allowed a small movement.
This is very difficult to see with the engine in the car.

back to it tonight, with a fresh plan thanks to you guys.

When I got all the pulleys lined up and created a LOT of tension on the exhaust run side of the belt then the belt went on reasonably easily
and with no swearing or cursing at all. It does take a lot of force WITH YOUR HANDS to get enough tension on the exhaust side to make it fit.

My experience has been that if the belt won't go on then something is not perfectly lined up.

I do note those above that say to ease the crank around slightly and if that works for you then fine, however i found with the pulleys on the timing marks the new belt went on fine.