Zetec Timing Belt

[GeeWiz1]

I have a pre '98 Zetec and I'm having difficulty establishing the correct

tension for the timing belt.

The Haynes manual say's to "rotate tensioner clockwise as far as possible

against spring tension" The first time I made it as tight as possible with

little twist in-between the crank pulley and the exhaust pulley (about a

1/16" deflection) and after engine warm up there was an indication that it

was to tight because you could hear some creaking from what would appear to

be the tensioner. So now I have the timing cover off and trying to reset

the tension. The manual directions don't make a lot of sense to me because

if you rotate the tensioner clockwise against the spring tension the belt

gets loose. Some one has suggested that I just make the twist in-between the

crank pulley and the exhaust pulley about 90 degrees - this seams a little

excessive so I have set it at about 50 degrees but haven't started it yet.

After a few turns by hand the belt has settled in and flexes about 1/16"

between the pulleys, certainly looser that before.

Any ideas or suggestions or personal experiences would be appreciated.

 

Thanks

 

Graeme

'95 Caterham, Zetec

 

[oilyhands]

The correct way to set the tension is by using a belt tension gauge, however a rule of thumb which works with most belts is to test the tension of the belt by attempting to twist the belt sideways, when you can *only just* twist the belt through 90 degrees in the centre of the longest belt run then the tension is correct.

 

Oily

[Paul Turner]

I have just fitted a new cam belt to the Zetec I am preparing for my car this winter and without having the Haynes manual with me at the moment I remember the steps were as follows (after removing all the covers and bottom pulley):

Turn the engine to TDC and insert the cam locking bar into the slots at the rear of the cams. Idealy you should be checking that the timing marks on the bottom pulley line up with lug on the sump.

Loosen the cam tensioner centre bolt and rotate the tensioner away from the belt, temporary retighten the bolt.

Remove the old cam belt (if this is the first time a belt has been renewed it is necessary to fit a tensioner pin and spring supplied with the belt - there was with my genuine Ford one) and then fit the new belt.

Release the centre bolt in the tensioner pulley, the spring will pull the pulley toward the belt and provide the correct tension (according to the manual). Leaving the centre bolt slightly loose to allow the pulley free movement remove the cam locking bar and rotate the engine through two revolutions then re-insert the bar. You should then have the correct tension and torque up up the tensioner centre bolt. Re-check the timing marks to check nothing has moved.

It seems to have worked for me but it is the first Zetec belt change I have done. It is very different to the Golfs and CVH's from my past that either required a 90 degree twist or the displacement to be measured. These methods always concerned me as both were open to individual interpretation as to the ammount of force required, the spring supplied is hopefully right.

 

Paul Turner

[GeeWiz1]

Thanks for your comments:

I will try to let the spring pull back on the belt tonight - I'm sure I have allready tried that once before and the belt was so loose that it started to jump. I gave up trying yesterday just to wait and see what responses I got from the posting.

My spring came with the belt so I'm sure its the right one.

Will let you know how I made out

Thanks

Graeme

[GeeWiz1]

Thanks for you advise it’s going great now – no more creaking noises and the tension idler seems to be working OK.

Now if I can the carbs set up so I can pull away without flooring the thing we will be all set. I’m booked in for rolling dyno Friday. What fuel delivery system are you using?

 

Graeme

[millsn]

If you're referring to fuel pumps I've had one from James Whiting. About £30 (from Weber concessionaires I think), very quiet in operation and Steve Foster also uses one on his VX with no troubles. I'd have to recommend it!

 

Nigel Mills - 2.0 Zetec carbs