brake rotor change..

I'm confused, (and apparently some aftermarket brake mfgrs seem to be too).
I have 11.5" (~292mm) front brake rotors on the disc brakes of my 2005 Subaru Outback which needs replacing. I have seen two different internet stores list that the correct replacement for my Subaru is 276.5mm which works out to be something like 10.88". And that the ones that are 292mm are for Normally Aspirated Subarus. (Mine is a turbo). This is really odd in that I've read from different sources that all 2005 subarus should have 11.5" front rotors and that the Turbo Subbies have just thicker rotors. Now why would I see 2 different sizes for the subaru and the one size that they say is for my Turbo subby the wrong size???? I can't see replacing the rotor with a smaller one would work but don't know if it's a measuring thing or what??? Anybody out there have experience with aftermarket parts not matching OEM parts but still working?

I've posted this on a subaru board but got nowhere... like nobody replaces their rotors

Jay

Re: brake rotor change..

Well I work for a company that makes brake rotors. We currently make the front rotor for the legacy, but not the outback. The size and shape of a rotor is designed with many factors including the weight of the car, HP of the motor, tire diameter, etc... In the old days they would not worry about putting a rotor made for a higher HP motor on a smaller car. But nowadays they are trying to cut every ounce of weight off and there are many different configurations.

If your car has 11.5" rotors, be sure to use the same size. The smaller one may not cool as well leading to warping and then shuddering in your steering. If you are in doubt, call your local dealer with you cars serial number and they should be able to give you the correct part number.

Re: brake rotor change..

Well, talked to a guy who sells brake rotors and whose wife has the same subaru that I have, still didn't get a precise answer but I presume since the guy seemed to know what he was doing and has the same car that I have, he wouldn't sell me rotors that wouldn't work. I will certainly measure them with my metric ruler when I get them so I know in the future if I still own the Subaru which size rotors to buy.

I think Subaru does this to confuse the hell out of people who DIY so they get robbed at the dealership to do something as easy as a brake job. You should read all the stuff about using Subaru brand's antifreeze when changing the coolant. Scare-tactics!

Jay

Re: brake rotor change..

There could be many reasons for the different part numbers, some reasons the manufacturer would prefer their customers didn't know about. I wont mention the company's name (not Subaru), but you may find this interesting.

This company has two midsized sedans. Looking at them side by side you would see no immediate reason the rotors should be different. In fact they both share dimensionally the same rear rotor, but the higher priced sedan has a better brake surface finish requirement. So if I need new rotors for the higher priced car, they will sell me the higher priced rotor when in fact the lower priced one will work just fine. They do have different front rotors though. Now the one sedan has a 2 door model. Still the rear rotor is the same, but the front is another part number. And then there are identical rotors with different part numbers because of different paint coverage. One may have more paint on it so it looks better with a certain wheel. The one with more paint costs slightly more.

Their new truck model was released. Warranty claims were high on the front brakes so half way through the model year they changed the design of the rotor only. It could not change too much because it still had to fit with the other components. It was better, but not good enough yet. They then did a total redesign of the whole assembly requiring yet another rotor change. So, if you have one of these trucks, there could be one of 3 different rotor part numbers on it even with the same motor and drive line. The part number depends on when during the year it was built.

I am sure that this is not just limited to the rotor industry, but I am amazed at the effort that is spent to knock 1 ounce of metal off a part or save $0.002 on a part by eliminating a drop of paint here or there. I know that it adds up to thousands of dollars a year when multiplied by the number of cars produced. But I don't think they take into consideration the added costs of changing over the production line, extra inventory, and tracking multiple part numbers.

Another example is I have Linksys WRT54 router. I found a "hack" that allows me to change the firmware. This extends the range and signal strength and turns "a $60 home router into a $600 professional router". I think the reason they do not sell it this way to home users is it takes more knowledge to mess with the settings with out damaging the unit. Also by turning up the output, a high pitched sound can be heard when the rest of the room is quiet. Not something you would want in a home router.

Re: brake rotor change..

really, hmm.

Re: brake rotor change..

I don't know about the "$600 router" part, thats why I left the quotes, but my signal strength was increased. There is an output power setting that you change in the new firmware. I have 3 units around the house that all showed a one bar increase in signal strength. Now obviously it doesn't do anything for the router receiving the signal from the computers.