C12 Serpentine Belt Help

[Edward Buker]

My coach does not have any tensioner decal like what is described in the Cat manual in the attached photograph. I know there are others who are in the same boat so I was hoping to see if we could get some info on the forum here that remedies that. As it stands now when we put a serpentine belt on, without this decal or any reference marks, we do not know if the belt is tensioned right and we also do not know when if and when it stretches beyond the limits Cat intended.

Someone who has a C12 in a Thunder or Marquis with the reference mark and the red and green decal could help get us all get calibrated. My motorhome is a 2002 but I think most any year that is close will do. What I am interested in is having a couple of Sharpie marks put on the tension adjuster as shown in an attached photograph. One centered on a casting mark and one centered on the movable casting that limits the travel. If someone is willing to help and would like to call me on 617-480 2980 to talk our way through getting these measurements done I would be a happy camper.

The dimension I would like to get is the measured distance between these two marks and at the same time where the tensioner is falling within the green limits.( i.e. The measured distance between the two marks is 1/2 inch and the tensioner is 1/8 th inch from center of the green on the upper side or lower side of the reference mark) The other dimension is the measured length of the green region on the decal.
Also let us know if the decal is placed on the right or left side of the tensioner as you look in the rear hatch.

This info would allow the rest of us to get some meaningful marks on the tensioner and some reference measurements. if you ever lose your decal you will also  have this reference to fall back on.

Regards Ed

[Edward Buker]

One more photo. Centered in this photo are the parts we will mark with the Sharpie...they are somewhat obscured by the measuring tape in the other photo. The casting line mark is one line placement, and then a centerline mark on the movable part of the tensioner is the other.

Later Ed

[Dick Simonis]

I remember seeing this post earlie so when I was fussing around in the engine room I took a pic of the tensioner decal on my C-12.  It's a bit hard to see all the colours but the red at the bottom indicated the belt is too short and as you look up the color will gradually shift to red as it gets too loose.  On the swing arm there is a little nub that point to the decal.

Hope this helps even if it's a bit late.

Dick

[Edward Buker]

Dick,

Thanks for recalling the belt tensioner posting and sending a photo.

 It would appear that your tensioner is a little different than mine.  Given we have different configurations, the placing of marks and taking measurements, as they were defined in the earlier post does not look possible on yours. I think I am going to have to come across a C12 with a tensioner that still has a decal and then figuire out how to get some relatable markings configuired for mine.  

Nice job on your overflow recovery tank set up. I'll have tackle that one when I am back home in the fall.

Later Ed