[PeterBlue]

The timing belts on my Carnival (2.5l / K5 / KV6 engine) were changed a few years ago, was done by a Kia dealer.

I have a leaking front oil seal which I decided to replace myself and in the process noticed that the dealer has installed the front belt with the printed 'driving direction' arrows on the belt pointing opposite to the direction that its driven (i.e. the arrows were pointing to the rear of the vehicle when the arrows were over the LH camshaft sprocket). I notice the Kia 'EM' engine workshop manual states that the arrow marks on the belt should match the driving direction of the belt.

The front belt has been running in the 'reverse' direction for about 45,000km and is in excellent condition, so the running direction is obviously not too critical.

Does anyone know why a running direction is specifed for these belts and hence what the implications are of it being run in the other direction?

 

[bruce2]

I don't believe it is critical as to which direction is to install the utility belts. It might have been different groove shape or fiber direction, but I thought the manufacturer would go through the trouble to make it different. Just for peace of mind, you can reinstall it in the direction as indicate or even replace it with a new one.

 

[Gidner]

It depends. Some belt are made specifically to run in one direction, which optimize the life of the belt as it is designed to stretch in that direction. In other cases, the arrows are just put there for refernce for the mechanics...if the belt is taken off and then reinstalled, it is easy to install it the same way again with guidance of the arrow. If your're belt has been on there for 45000 km, do not take it off and put it the "correct" direction. That would most likely lead to a snapped belt in the near future. So leave it like it is or replace it with a new belt. Not sure if the current belt would fail prematurely due to spinning in the opposite direction, but they have good design margins on these things. Is it an OEM belt or after market that is installed now. The OEM belts usually lasts way past the recommended replacement interval (you have to believe that they fudge that margin to avoid liability/reputational issues)

 

[PeterBlue]

Thanks for the replies & advice.

Gidner, yes I figured it wouldn't be a good idea to reverse the belt at this stage of its life, so have left it in its 'reverse' direction.

And in answer to your question yes the dealer did use a genuine Kia belt.

Looking at the somewhat faded printing on the belt I can see that, in addition to Kia branding & part numbering it carries the Gates logo and their 'PowerGrip' branding. I checked every applicable reference I could find on the Gates website and there was nothing that I could see that indicates a specific driving direction. In fact only reference that I could find at all in their doco to the arrows was this:

4. Directional arrows (these are used to make sure the belt is running
in the proper direction of rotation for the belt timing marks to line up
with the engine marks).​

(Looks like they make some belts with timing marks pre-printed on them).

So Gidner I think you're on the money when you suggest the arrows are just there to make it easy to reinstall a belt in the same direction. While circumstantial, (Gates don't say they can't be run in the reverse direction) it seems that's likely all that's behind the note in Kia's workshop manual.

 

[Gidner]

Good. Yes, some belts also have timing marks across the belt in addition to the directional arrow. I think you'll be fine with your belt (but I am not an expert, so you will have to make your own decision on that!). I think you have what, 30,000 miles to go until the next change interval. Maybe just keep an eye on it every now and then?

 

[PeterBlue]

Thanks, good advice.

Its interesting that some belts have timing marks printed on them. The Kia belt doesn't but, following a tip I read on a Rover forum, I put my own marks on the belt and each sprocket after rotating to the timing position and before taking the belt off.

Not really necessary of course, but it was reassuring confirmation on reinstallation that I had the same number of teeth between the sprockets that it had before it came off, and hence had correct tension on the idler and waterpump runs. If/when I change the thing I'd do that again and transfer the marks to the new belt.

Incidentally, I notice Bosch say of their belts: "Bosch timing belts can be installed in either direction without compromising their operating characteristics. The printed arrows on the timing belts are only required for certain vehicles with ignition timing markings."