Thread: serpentine belt direction

i've seen them laminate if put back on the other way, must have something to do with the way they have stretched under tension when fitted previously i would think.. bit like tyres...

Originally Posted by wally

Something I read recently said that when removing the serpentine belt (300Tdi), mark the direction of rotation so that it can be re-installed the same way. I've never heard of that before. Can anyone suggest a reason why you would do that?

Cam belt yes (it's mentioned in the manual) but I've not seen it for the serpentine belt.

M

Originally Posted by incisor

i've seen them laminate if put back on the other way, must have something to do with the way they have stretched under tension when fitted previously i would think.. bit like tyres...

I am guessing you mean DE-laminate...

I am not sure about the tyres comment though.

When I rotate my tyres I bring the rear straight up to the front but I rotate the fronts diagonally to the rear. This changes the direction of rotation which I feel helps to even out any shoulder scalloping.

I have been doing this for years (14 plus) with no ill effects whatsoever.

Originally Posted by incisor

i've seen them laminate if put back on the other way, must have something to do with the way they have stretched under tension when fitted previously i would think.. bit like tyres...

like big john said, I think you mean delaminate.

when a belt has been running in a certain direction all the fibers have been pulled from the direction of rotation for so long so when you fit it back on the wrong way the fibers aren't use to being pulled from that direction and can delaminate and snap. most things that have been loaded up or tensioned should go back into the same place they came from, rigging screws(turn buckles) is a good one, because of the load on them the male and female threads stretch together and now are matched and should not be mis matched. hope this helps

Yep, I always mark on the old ones I remove the direction of rotation with a paint pen as they are used as emergency spares (not that I've ever needed one)

BTW Wally, Warwick was looking for your ph # to give you a ring, has he PM'd you yet ?

Originally Posted by wally

Can anyone suggest a reason why you would do that?

Don't know whether they delaminate or not, but I simply make it a habit to have the printing on the belt facing me; ie towards the front of the car. That way the belt will always be going the same way.

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Nigel

Are you sure they dont just mean the route that it takes? as opposed to the diretion it rotates in?

Sometimes unless you make a note of where they went it can take hours to get them back on!!

Originally Posted by Psimpson7

Are you sure they dont just mean the route that it takes? as opposed to the diretion it rotates in?

Sometimes unless you make a note of where they went it can take hours to get them back on!!

No, it's meant for the direction of rotation of the belt, you mark the belt in the direction of rotation like mentioned before use a paint pen and arrow the direction on the belt, if you want you can draw a picture of the pulleys and idler and what ever it goes around on a piece of paper, but that is a seperate thing to the above.