comment on 'how-to' variomatic/CVT article

[antiekeradio]

http://www.volvo300mania.com/forum-uk/v ... m.php?f=20

I have suggested that this operation is to tension the drive belts but this is only partially correct. It is true that if there is no secondary unit pully gap at all the belts will be too slack and may well slip (and overheat and degrade) but by setting the pulley gap too wide you will reduce the highest gear ratio available

setting the pulley gap too wide will not only reduce the highest gear ratio available, it will also destroy the drive belts....

the explanation is that because of the maximum pulley gap in overdrive position, there is a point when the belt cannot cause any increase in pulley gap, no matter what tension it is pulled at.

the setup of pulleys and drive belt width is such that in normal conditions, before the maximum pulley gap of the secondary pulleys is reached, the primary pulleys are closed fully, which stops the increase in belt tension.

if the primary pulley cannot close fully when the secondary pulley is at its stop, tension in the belt will not be limited and may go on increasing (due to higher revs) up to the point where belt tension is so high that the belts fail.


so; set the gap correctly or your belts may get in trouble...

[pettaw]

Thanks for the heads up....I'll modify

[petefarrell360]

Good call. Mine are definitely too far apart at the moment, as now, every time I pull away on an incline it results in the belts slipping, I need to sort it out, new belts are also required really! Trying to sort out the GLT first, waiting for the new windscreen! Then the Vario will get new belts etc if I can track some genuine ones down!
Pete

[antiekeradio]

if the belts are slipping the pulleys are too close together, not too far

[petefarrell360]

Well spotted! Knew what I meant, and after a night on the cider got it wrong, yep, meant the gap wasn't wide enough! Simple enough to do, just no time!

Pete