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Diesel VW cambelts - Round teeth = too tight?

Hiya. Anyone else found this?

The last three Volkswagen cambelts I've changed. One a VW Transporter, one a Polo, and one a Toledo (VW engine) all diesel. I've found the new belt very tight to fit. In fact the only way I've been able to fit them, was to half put them on the crank, and turn the engine slowly by hand, until the belt eventually works it's way on. It seems that the old belt has flatter teeth, that sit nicely in the sprockets, but the new belts seem to have round teeth, meaning they don't seem to fit in the pulley right. When you finally manage to fit the new belt, it seems to fit into the sprockets OK, but only because it's under so much tension.

I've been in the trade for over 10 years, and fitted many many VW belts, and only until recently, have I had this problem. There must be others out there, that have come across this? All cars have gone out OK, but I don't like the idea, of the belt wearing into the pulleys, then becoming the wrong tension.

Anyone thoughts on this?

Matthew

Reply to
Matthew Long
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This sounds wrong to me, what make of belt have you been fitting?

I had a similar incidence with a Vectra (ecotec engine) where the belt supplied (by owner) had half-moon section teeth, and the sprockets were a square cut out. After fitting the belt made an alarming whine and I was not happy. I Insisted on a genuine Gates / Vx belt, which then had the correct square shaped teeth. This was of course fine.

With something like timing belts, using something other than genuine isnt worth the risk! Tim..

Reply to
Tim (Remove NOSPAM.

Snot a manufacturer thing though, it's a buying the wrong belt thing. Some Vauxhalls have half-moon teeth, some have square cut. You can come across the same problem when buying water pumps for them.

John

Reply to
John Greystrong

Yes - you're fitting the wrong belts. There are two distinct tooth profiles and the pulleys should exactly match. The round tooth form for highly loaded belts came out on the Ford CVH to replace the shallower square tooth form on the Pinto. The pulleys are completely different in each case. Whatever your current belt supplier says, if the pulley is square tooth form then you need a square tooth belt.

I'd be looking to recall anything you've done like this recently and fit the right belts or it's an expensive accident waiting to happen.

Reply to
Dave Baker

The message from snipped-for-privacy@aol.comNoEmails (Dave Baker) contains these words:

You'd think they'd have the wit to change the pitch slightly so there's no chance of fitting the wrong one!

Reply to
Guy King

The pitch of 3/8" is a standard in belts and chains dating back to the days of Reynolds and I suspect that changing that would have caused more problems in manufacturing and loss of standardisation. The tooth form is so different I find it hard to believe that anyone could fit the wrong ones to be honest.

Reply to
Dave Baker

"> Yes - you're fitting the wrong belts. There are two distinct tooth profiles and

All belts were genuine VW parts. On all three separate occasions, after struggling to fit the new belts, we rang VW with chassis, and engine number, and it was listed as the correct belt. Again, tried to fit belt, again, rang VW. This has been the case for the last 3 VW diesels. Even changed the tensioner, in case that was modified. Still the same. It's a real mystery. It's been on 3 different models too. So not related to just one model. Even checked the part number from the old belt, and it ties up with the new one.

Explain that!! Lol!

Matthew

Reply to
Matthew Long

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