fan belt

Post by **henry martin** » 18 May 2007, 21:39

It screeches like a banshee
but only on start-up,

once its given an initial rev to stop it,
its fine,
and not a peep out of it
until next turn of the key

is alternator too tight?

Post by **Fritz** » 18 May 2007, 23:28

I don't wish to state the obvious but have you lifted the lid to check the tension of the afore mentioned belt ?

Regards

Fritz,,,,,,,,,,

Post by **henry martin** » 19 May 2007, 09:56

Obvioulsy I checked it for tension
before posting and found perhaps
1/4 inch at longest point,
which does'nt seem that much
perhaps it is i dunno'

anyway removed battery this morning and slackened off the alternator bolts,
got a bar underneathi it, got a bit more tension on it and pinched up the bolts again, Its quiet on starting but now squeeks on revving it sometimes.

Might be worth swapping belt for a new one
in case its damaged although it looked fine when I checked it earlier

Post by **mcalp** » 19 May 2007, 10:16

I had the same problem last week. got a replacement belt and found that the original, although it looked ok, had worn on its edges so that it was no longer 10mm wide but more like 8mm and consequently when tensioned up was sitting in the bottom of the pulley flanges.

Post by **henry martin** » 19 May 2007, 12:34

Right so mine also looks OK
but I'll compare it with a shiny new one from Halfwits and see how it looks then

cheers

Post by **phade** » 19 May 2007, 13:18

I don't know which engine you have in your van (wether it is an Aircooled, wasserboxer or an inline one).

If you van has an Aircooled or a wasserboxer engine in it, then the fan belt deflection should be about 13mm (1/2 inch) at the centre of the belt with light thumb pressure. 6mm (1/4 inch) is far too tight and may destroy the alternator in the process.

Post by **Balaclava** » 21 May 2007, 11:02

My alternator belt keeps snapping. Is it too tight? Have I put in the wrong size? I've gone through three belts in six weeks. First there is a smell of rubber burning then...snap. Also had the squealing!

It's just dawned on me that the engine is somewhat newer than the van, B reg, does it matter that much? Is there a standard size for alternator belts on all T25s?
It's so awkward to replace everytime.

Post by **phade** » 21 May 2007, 23:22

Yep you have done the fan belt up far too tight !!!! You may have also damaged the alternator as well.

If the alternator makes any runbling noises or if there's vibration on the alternator's pulley, then the alternator must be replaced immediately. This is imperative on all Aircooled models.

As I said before the fan belt's deflection should be approx 13mm with light thumb pressure. This is measured from the centre point of the belt its self in one direction only. The actual VW specification for all Type 2 T3s is the following:-

New belt: 10mm with light thumb pressure
Old belt: 15mm with light thumb pressure

Setting the alternator belt's deflection correctly is critical. This is particularly important for all air cooled models.

Cause Reason
Battery not charging Alternator belt too slack, worn brushes or alternator worn out
Overheating (Aircooled models) Alternator belt too slack.
Whining noises, vibration Alternator belt too tight.
Engine labouring Alternator belt far too tight.

Post by **Balaclava** » 22 May 2007, 00:53

My engine, (diesel) is water cooled. Any difference?

Post by **phade** » 22 May 2007, 04:37

The fan belt tension is the same for all boxer (both Aircooled and watercooled) engines and as far as I can see in my VW booklets set it's also the same for all of the inline engine ones too.

Post by **Ian and Lins** » 22 May 2007, 06:57

Just a thort but if it is only squealing occasionally it may be that the battery is on the way out. The thinking is that the alternator is under a greater load to 'top up' the battery and so offers resistance to the fan belt. (Any real sparkies out there can shoot me down on this)

Post by **kevtherev** » 22 May 2007, 16:11

rubber on steel .....squeal..belt jiggered

Post by **toomanytoys** » 22 May 2007, 16:17

Could even be the waterpump (on a WBX) on its way out.. had this happen..

I use the "can you twist the belt 90 degrees" mid way along the longest route.. this seems to work very well, you shouldnt be able to do it too easy or need lots of force..
fit a new belt....

Post by **jonnyk73** » 22 May 2007, 19:01

I'm with toomanytoys on this one.........spent today changing the waterpump.

Noitced that the bearing was noisy, this last week or so the belt started to slip, the waterpump bearing was really worn resulting in it seizing yesterday.

£31 for the pump and belt from gsf, runs like a dream now!

Post by **Balaclava** » 22 May 2007, 23:42

Right, this is really doing my head in!
Fitted yet another belt on alternator today. First time I drove off, the red light on dash came on. I had the belt quite loose.
Next I tried tightening it. The light comes on sporadically and sometimes only very dim. Trouble is now it squeals like hell! Squeals at low speed, get up to thirty miles an hour and the squealing stops. Still have occasional smell of rubber burning.

What the hell is causing the squealing? Surely it can't all be this complicated? Could the squealing be coming from the alternator itself? It does get very hot and smokes a bit. Maybe the smoke is coming from the belt.
Looks like I will have to bring it down to Jacks Garage in Notting Hill to get them to fix it. A simple job to them but they charge a fortune.

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