Quote Originally Posted by Daox View Post
New belt installation:

On a flat work surface, place the new belt on top of the old one so that they line up exactly. Mark the new belt in the same locations as the old one. Now count the number of teeth between the marks on the old belt and make sure you have exactly the same number of teeth between the marks on the new one. The last step is a bit overkill, but you'll be 100% sure that you have everything just right.
Thanks for a great write-up. I originally thought the marking and counting was overkill, but am glad I did it just for the peace of mind. The replacement belt was fine, but on a cool night wouldn't relax very well from the bizarre shape it acquired during shipping. I did manage to mount it correctly by feel, but would have been very apprehensive over being a tooth or so off if the marks had not been there for confirmation - like I said, a fortune in peace of mind.

I installed the new belt and idler on our 2004 HB with 45K miles the night before taking it on a 1,000 mile run. Both a trusted mechanic and the local Chevy dealer had said not to mess with it until 60K, but of course neither had any knowledge of the early timing belt problems. The OEM GM/Gates belt I removed was in pretty good shape, just starting some light surface cracks on the backside. The original owner did maintenance by the book at a dealer for the first 30K miles, so suspect he got it changed out in the GM early replacement program as there was some hose insulation damage indicating the upper timing cover may have been off before.

Would have liked to have changed the tensioner and coolant pump, but couldn't afford the additional time if there had been any snags... and I seem to find at least one snag under these sorts of time crunches. So guess I'll be changing it again around 75K unless the pump starts leaking sooner.

Can the tensioner actually be replaced without removing the cam sprocket? It was late and I didn't take a hard look at it, but didn't appear I could get to all three bolts with the cam sprocket in place. Is that correct? I had the cams locked, so didn't take time to check if I could get to the bolts by rotating the cam, using crowsfeet, or some other option.