Club 80-90 Forums

Just took the fan belt of my 1.6d cs engine in order to get size to order new one. It's a 11.3 x 912 belt. Quick Google search tells me this fits beetle and T2. Everything advertised for t25 1.6d is 10mm width. It's been working fine apart from slipping a bit on first start up on damp days but I'm at the end of the adjusted on the alternator so I need to replace it. What do folks think? Like for like or should I go 10mm? What's everyone else got?

Thanks in advance.

That belt doesn't sound right. From memory it should be a little more than 600 long (10mm wide) exact length depends on alternator fitted. Might explain why you're at the end of the adjustment.

Every time I see this query I wonder why people don't just measure the pulley width and the belt run. It isn't rocket science. Surely it is better to buy what will fit the measurements than guessing. Our engines have had 30 years of tinkering with alternator changes/pulley changes etc so it is unwise to rely on someone saying that such and such a size will fit or manufacturer states....
For those that need assistance there is always an online calculator such as this http://www.durabelt.com/beltlengthcalculator.php

I now have a new fan/alternator fitted. I went into motor parts direct (very helpful) we went through all the options for my engine and I decided on a 10 x 875. Close to the size of the 912 one that came off but puts it away from the end of adjustment. It fitted ok so all good. But having a better look I have a double pulley. I measured from bottom to middle pulley and it's 600 which makes more sense to what people were saying. Should I been running 2 belts? I took a photo.

Sent from my Moto G (4) using Tapatalk

yes would normally be two belts, one from crank to water pump (middle/double) pulley, another from the pump to the alternator. Running a single belt as you are at present shouldn't pose any problems provided it contacts well on all pulleys/everything is turning and you've obviously not had a problem until now. Difficult to see in photo but it does look as though the pulleys don't quite line up so maybe that's why it was switched to single belt, or maybe it's just the angle of the photo

muttleypup wrote:yes would normally be two belts, one from crank to water pump (middle/double) pulley, another from the pump to the alternator. Running a single belt as you are at present shouldn't pose any problems provided it contacts well on all pulleys/everything is turning and you've obviously not had a problem until now. Difficult to see in photo but it does look as though the pulleys don't quite line up so maybe that's why it was switched to single belt, or maybe it's just the angle of the photo

Thanks for the reply. I think it's the angle on the photo. I just found this pic on the net which shows how the belts should be. I think I'll get the 2 belts and try that. The belt I took off had been rubbing on the plastic cam belt cover but I'd put that down to that belt being the wrong one.
Sent from my Moto G (4) using Tapatalk

Ah yes it did look close in photo. Just as a start point, belt from crank to pump on mine is 10 x 643, pump to alternator 10 x 613. The water pump pulley is in two parts and the pump belt tension is adjusted by adding/removing shims. Brickwerks do the shims, if yours have gone missing.

Brilliant, thanks. That will justify the postage for the 80p dip tube seal I need to buy.

Sent from my Moto G (4) using Tapatalk