I think the big problem with flat rate (and I actually generally agree with it) is that like much of this world, if it's not in the book people are clueless. Most places I checked didn't have any listing past early 80's so they couldn't even give me a figure. Add to it, that in reality, some jobs are "built into" other jobs...yet shops will still charge the rate, which I find unethical. If a smaller job has to be done to finish a bigger job, many shops will still bill the time for the smaller job, even though, technically all the labor is being done on the larger job. For example...say on an engine, you have to remove the water pump to get to the timing belt.....many shops will say "now is a good time to replace the water pump" so you do....and then many shops will charge you book time for replacing the water pump on top of changing the timing belt, even though all the labor to change the water pump was required to do the timing belt....in essence, they are billing you twice for the same labor....where as it should be just get a different water pump to put in when it goes back together, rather then put the old one back in.
I really have no idea on the example, as I'm not familiar with internals of engines...but I've heard it a lot....and only a few shops I've ever contacted/dealt with have been upfront about "oh, well that labor to do YYY is already being done to do XXX, so it's no extra charge other then the part" Whereas I contact more shops that are "that'll be 4 hours for XXX and another 1.5 hours to do YYY"
As for my original question..I have no problem paying a "fair going rate" but I was curious, because I would assume that since it says 1.5-2/hrs a side, that if both sides were being done together, the labor involved would be double billed, or at least a good portion of it...since you have to get the carrier out to do just one side, why does it require paying to get the carrier out to do the other side as well?