This actually happened with the SBB in my car, but I may be facing the same choice when I install the BBB... I removed all of the air conditioning system under-hood components on my Skylark. This resulted in one empty groove in my balancer, water pump and alternator pulleys. That always looked "wrong" to me. (I know, I know, I'm way too picky.) Anyway, I purchased two new alternator belts and used the second one to fill the empty grooves in the pulleys. It took a couple trips to my local independent auto parts store to get two belts that appeared to be the "exact" same size (due to manufacturing tolerances). So, I installed the two identical appearing belts in such a way that the logos, size and part number info, etc. on the two belts were right next to each other. Everything looked great although the logos, etc. on one of the belts slowly moved ahead of those on the other belt. I also noticed that it was necessary to lubricate the belts fairly often to avoid a noisy-belt condition. So, either the belts weren't exactly the same size, or there were variations in the diameter of the 2 alternator belt grooves in the three pulleys (even tho they looked the same). Assuming I resolve the belt size match-up situation, has anyone experienced a belt throwing incident when trying to run two alternator belts? If so, were you able to fix the problem? How? Thanks in advance for your help.
I would not run 2 belts on my Alt just for the sake of Bearing longevity, as it really loads the snout of the Alt a bunch more! When I was a mechanic in the 70s near all the GM Alt's that we saw with early failed bearings where the duel pully type! I would get a shot old Alt with a one groove pulley and use it to replace your duel pully.
Hi Dan, I went through this a few years ago and I was told they don't make matched sets anymore. As far as loading the snout more, I don't think that would happen if the belts were matched. You can always try to switch the belts you have(in to out and out to in) to see if that helps with throwing them. The only way I solved mine was to go serpentine. Just make sure your belts are the same width also, seems tolerances are not watched really close from belt to belt.
Matched-sets were something we used a long time ago. Yes, they did work. According to Gates, manufacturing has gotten better and the need for 2 belts from the same run packaged together is no longer necessary. However, if you go to your favorite parts house for Gates belts, beware that you have to have a parts guy that knows what he’s doing to make sure that the serial numbers are reasonably close so that you don’t get an old belt and a new belt.
