You are correct I misunderstood, I thought he wasn't sure what caused the noise. Not that he wasn't sure why the failure can still occur with the tool. My understanding on why using the tool can still possibly fail is a couple of reasons.No, he understands what makes the noise, just not why when he's used it in the past that it led to the whining noise in about 90% of the cars that he's used that tool with. In other words, it sounds like he's saying that he doesn't understand why it didn't work every time for him and that he doesn't know what he did wrong when it did lead to the whining noise afterwards.
As for why he prefers to open up the case instead of using the tool, that's what I don't understand either. Except for him being leery of the tool, that TSB didn't sway him in the least and he's still saying that he'd prefer to open the case up. And I agree: if the case is opened up, it shouldn't be that much more of a pain to swap out the chain stuff to be safe, but when I asked about that, he made it sound like doing that would bump up the costs closer to $2k+ and I think a lot of these costs come from the GM job rates that he seems to reference whenever I ask him about things like this. (He always says that X job looks to take Y hours of labor, like he's referencing something offline. I guess their techs have things like that on their systems that they use to provide customers with quotes?)
Part of me suspects that he's thinking that he's saving time by opening the case because if it's opened, he can reset the tensioner right there. Is there any virtue in that line of thought?
You and others on here all claim that the tool is okay to use if used right, but nobody ever clearly explains how that's done. I've seen YouTube videos of it online and it does look like it should be a simple affair, but I'd imagine it's much more of a pain to use when you have to bend over the fender into engine bay to reach out things or reach up from underneath when the car is raised without having clear line-of-sight to the sprocket holes, let alone, the bolts attaching it to the WP. I can see how even the slightest cross-threading or incorrect angle of one of those bolts could lead to major problems... And I can imagine how even the slightest amount of slack during that work for the chain could lead to that tensioner easily ratchet up like a spring trap (assuming that's all it takes for that condition to happen)...
If I can get him to come down to about $1,400, I'm going to let him do it. But I hear a whine after that, all hell is going to break loose.
That's VERY interesting, thank you. This may well explain why folks (and dealers) have had issues with the tensioner even when they used the tool.I did the WP change using the tool and kept the cover on the front. It was A-OK. You have to make sure you use the tool properly. Mine I had to tighten down a few turns at a time on the holding bolts and then the sprocket bolts, then back and forth multiple times till all bolts were off. It was weird at first as I thought once it was tight on the holding bolts I was all set. But no, there must have been some ... play, or interference? Anyways I did it and no whine and did not mess up the timing.