Timing belt direction

dnsey · Post by **dnsey** » 30 Apr 2006, 10:59

I have just changed my timing belt (Xantia 2.0 16V), and just as I was finally checking the tension, realised that the new one has 'direction' arrows on it, and I'd fitted it the wrong way round. Bearing in mind that many are not directional, does anyone know what the difference is, and if it matters much to have it the wrong way round?

Dave Burns · Post by **Dave Burns** » 30 Apr 2006, 11:12

It will likely as not be to do with the construction of the belt, specifically the strengthening cords inside it. premature failure might be the result of it running backwards.

Dave

andmcit · Post by **andmcit** » 30 Apr 2006, 13:35

It MAY be down to allowing the correct orientation of the cog timing marks that the belt manufacturer will likely have printed on the replacement belt.

That said, I personally wouldn't take the chance, risk [call it what you like!] of going with the belt running backwards effectively.

For total piece of mind I'd concur with Dave. Get it right now so you wont cringe EVERY time the engine starts or revs up etc...

Andrew

mpr1956 · Post by **mpr1956** » 30 Apr 2006, 13:38

Hi Dnsy.. this is no help at all, but I do feel your pain... Imagine clearing up after a long clutch job on my old BSA years ago to find the pushrod lying on the ground. You know what you have to do, or you'll not have piece of mind.. best wishes, Martin

citronut · Post by **citronut** » 30 Apr 2006, 15:49

even when they have no direction markings it is rule of thumb to have lettering the wright way round when looking from the O/S wing at the engine
regards malcolm

reblack68 · Post by **reblack68** » 01 May 2006, 12:27

mpr1956 wrote:Hi Dnsy.. this is no help at all, but I do feel your pain... Imagine clearing up after a long clutch job on my old BSA years ago to find the pushrod lying on the ground. You know what you have to do, or you'll not have piece of mind.. best wishes, Martin

I know of a Land Rover owner who spent several hours undoing everything so he could remove a half shaft, this was a well used Landie so it was no mean feat. Only then did he realise he'd parked too close to the wall for the shaft to come out. I believe he was close to tears.

AndersDK · Post by **AndersDK** » 01 May 2006, 12:40

Anyone ever found a warning on the timing belt pacakge (or insert) - against fitting the belt "wrong way around"

Everybody : take a look on your cambelt and report back if you find the arrow pointing backwards - or the text reversed as pr Malcolm

My bet is if you really did take the effort to do so - we would have quite a few reporting back on a "wrong way around" fitted cambelt

Note : all recent transverse engines (and hence the cambelt) runs the same direction as the wheels. Meaning the arrow on the cambelt should/would point forward on the vehicle.

andmcit · Post by **andmcit** » 01 May 2006, 13:01

AndersDK wrote:Anyone ever found a warning on the timing belt pacakge (or insert) - against fitting the belt "wrong way around"

Everybody : take a look on your cambelt and report back if you find the arrow pointing backwards - or the text reversed as pr Malcolm
My bet is if you really did take the effort to do so - we would have quite a few reporting back on a "wrong way around" fitted cambelt

Note : all recent transverse engines (and hence the cambelt) runs the same direction as the wheels. Meaning the arrow on the cambelt should/would point forward on the vehicle.

Can't say I've ever bothered with the packaging but I HAVE made the effort to line everything up and get the belt's marks matching the respective marks on the pulleys.

The belt manufacturer will naturally expect everyone to do the same and anyhow no doubt hides under an all encompasing disclaimer to cover their 'responsibility' ie. liability, EVEN when a belt IS fitted correctly.

Just because other belts MAY have been fitted going 'backwards' to their intended route doesn't mean they're right and in fact this could be why you hear of premature snapping of these with the resultant mess sold for peanuts on ebay!!

As I've said already, is it REALLY worth the anxiety on top of the 'is it tight/loose enough' etc etc...

Bite the bullet, fit the thing according to the arrow and timing marks on the belt - end of story!

Andrew

AndersDK · Post by **AndersDK** » 01 May 2006, 13:30

I receive you loud & clear Andrew -

No gambling pays with the cambelt - I certainly do agree.

dnsey · Post by **dnsey** » 02 May 2006, 10:46

Thanks for your comments guys.
I was really hoping that someone would tell me that the arrows were just for reference when refitting a used belt

I think you have a point though, Anders. The box has the usual warnings re. tension, alignment etc., but no mention of direction. Perhaps I'll contact the manufacturers before reversing it.

alan s · Post by **alan s** » 02 May 2006, 13:41

I'll take a guess here and say you are "possibly" safe and that the arrow as well as the markings are only datum points but............I have been told by more than one tyre guy that if you have even non directional radial tyres on your car and you rotate them diagonally, meaning you reverse the rotation, that they will wear out almost before your eyes due to the internal webbing being stretched in a certain direction and if reversed that it will drastically increase friction and tyres will wear out prematurely which begs the question, if the belt has been fitted and run for any length of time, will the same apply to cambelts?
I do know that "3rd Generation" belts are supposedly stretch free and as such are supposed to last up to 50% longer than the old "First generation" belts that gave all the problems.

If it were me, I'd invest in a phone call to the manufacturer as there are a few too many variables IMHO to take the risk.

Alan S

Kowalski · Post by **Kowalski** » 02 May 2006, 15:08

What difference does it actually make if you reverse them? Belts operate symetrically and in tension. If the drive pully is pulling on the belt in one direction, the driven pulleys are pulling on the belt in the opposite direction as they are driven.

f00lzz · Post by **f00lzz** » 02 May 2006, 16:53

alan s wrote: If it were me, I'd invest in a phone call to the manufacturer as there are a few too many variables IMHO to take the risk. Alan S

My thoughts exactly... most manufactures have a techy dept.

dnsey · Post by **dnsey** » 03 May 2006, 12:20

I spoke with Dayco's technical rep (a friendly guy called Andy), who confirmed that the arrows were only there to locate any timing marks on the belt - the actual running direction doesn't matter. This is backed up by Dayco's useful 'failure mode' table, which lists causes of failure by symptoms, but makes no mention of incorrect direction.
Quite a relief, and useful information for the future!

f00lzz · Post by **f00lzz** » 03 May 2006, 12:35

Well Done! Would be nice if this info could be located in a suitable place such as 'handy tips'