I thought I had JE5 Brake Discs...But?

[MAC]

I thought I had JE5 brake discs but after putting on one of the Duralast disc I bought from AutoZone, I was concerned that I bought the wrong size. The Duralast was obviously bigger than what was on the car. I'm thinking, it looks like the caliper bracket may not fit. So, I put the disc on--and thought--WOW! That is one pretty big disc! But, what do you know, the bracket fit with about 1/16 to 1/8-inch to spare. Apparently, the discs that were on were not the right ones, which explains why my brakes are gouged/grooved on the inside. The rotors I replaced didn't have enough surface area to accommodate the larger JE5 brakes. I suspected something wasn't right and now the new discs confirm that I was driving around with undersized discs. What else, since the Duralast discs are for JE5 brakes, have more surface area, and fit. My guess--and most logical answer--is that the original factory discs were replaced before I bought the car with the wrong ones. Now I have to replace the brakes a soon as possible, so I don't damage the discs. I also have Duralast on the rear. So far, so good. They are holding up well after at least 6 months.

[Cadillac Jim]

I found that most mechanics, unsuprervised, will simply use the cheapest parts available that cross over to your car in the parts book, particularly if the car is more than a few years old. Most of them will think you are nuts if you object to this.

Something similar happened to me with my 1997 ETC. The brakes seemed OK driving home but I checked the part numbers on the brake disks and they were ultra-cheap. The owner's manual says that the car is guaranteed to go 150 mph, but I wonder what would happen if you pulled it up to, say, 120 mph (the cars are electronically governed at 125 mph unless they come with Z-rated tires) and pulled it down to 55 mph when the Passport goes off. I don't do that, but that kind of performance is what I bought the car for and what I expect of the car. I found that the simplest solution was to upgrade to PowerStop brakes. Those are high-metallic pads with drilled and slotted rotors, and require a burn-in process that heats up the brakes, and if you put around at 35 mph for a year you might need to do it again occasionally to keep best performance, but they fill the bill at a reasonable price.

[MAC]

It seems there are not many honest mechanics. I need to buy tires and need front end aligned. I hestitate to have someone do the alignment because the steering wheel needs to be straightend along with the alignment. So, I'm thinking of doing the alignment myself via the string method, just to make sure the steering wheel is properly aligned. Then bring it to a Cadillac dealership to check to make sure it's okay. I don't want to get my car back only to find that my request for a steering wheel alignment was ignored. I replaced both the inner and outer tie rods and both front hubs, so obviously the alignment needs to be taken care of.