# Rotor other than brake rotor? **URL:** \ **Category:** Factual Questions\ **Created:** [November 21, 2003, 1:59pm UTC](https://boards.straightdope.com/t/rotor-other-than-brake-rotor/214488 "2003-11-21T13:59:10Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![hauss](https://avatars.discourse-cdn.com/v4/letter/h/5fc32e/32.png) [@hauss](https://boards.straightdope.com/u/hauss)\ **Post date:** [November 21, 2003, 1:59pm UTC](https://boards.straightdope.com/t/rotor-other-than-brake-rotor/214488/1 "2003-11-21T13:59:10Z")
My friend recently had a whine in his 2001 Dodge Ram truck whenever he turned left. He got it fixed by a friend who said he had to replace the front left rotor. But, he said it wasn’t the brake rotor. By the way, he said it costed $170 for one of these. What rotor is it? Is this common a replacement after 30k miles? ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [November 21, 2003, 2:38pm UTC](https://boards.straightdope.com/t/rotor-other-than-brake-rotor/214488/2 "2003-11-21T14:38:25Z")
Sorry, but the info given does not make sense. Brake rotors do not cause whining noises on turns. There is only one “left front rotor” on a vehicle, and it is a brake rotor. The only other rotors on cars/trucks are distributor rotors (fading into obsolescence, not present on 2001 vehicles) and alternator rotors (virtually never serviced in the field). If you’re talking about the cost of the part, 170 doesn’t sound right for a rotor. I suspect that the offending part was the left front wheel bearing. It is part of a bearing & hub assembly. Perhaps your friend or his friend didn’t know to call it a bearing & hub assembly, or just a bearing, and thought it was called a rotor. ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [November 21, 2003, 2:54pm UTC](https://boards.straightdope.com/t/rotor-other-than-brake-rotor/214488/3 "2003-11-21T14:54:49Z")
I suppose it could have been the rotation sensor for the anti-lock brakes. Just a guess. ---
**Author:** ![hauss](https://avatars.discourse-cdn.com/v4/letter/h/5fc32e/32.png) [@hauss](https://boards.straightdope.com/u/hauss)\ **Post date:** [November 21, 2003, 4:19pm UTC](https://boards.straightdope.com/t/rotor-other-than-brake-rotor/214488/4 "2003-11-21T16:19:32Z")
I knew this didn’t sound right. My thoughts were exactly yours, GaryT. What the heck costs $170 that could conceivably be called a rotor and could cause a grinding whine on a left turn? Can’t think of anything… I think I’ll look into this, hopefully my buddy did not get ripped… but the sound _is_ gone. ---
**Author:** ![Rocketeer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rocketeer/32/4437_2.png) [@Rocketeer](https://boards.straightdope.com/u/Rocketeer)\ **Post date:** [November 21, 2003, 7:53pm UTC](https://boards.straightdope.com/t/rotor-other-than-brake-rotor/214488/5 "2003-11-21T19:53:16Z")
Sounds like a wheel bearing to me. ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [November 21, 2003, 8:03pm UTC](https://boards.straightdope.com/t/rotor-other-than-brake-rotor/214488/6 "2003-11-21T20:03:24Z")
The price is not out of line for a bearing/hub assembly. ---
**Author:** ![Berkut](https://avatars.discourse-cdn.com/v4/letter/b/a88e57/32.png) [@Berkut](https://boards.straightdope.com/u/Berkut)\ **Post date:** [November 21, 2003, 8:24pm UTC](https://boards.straightdope.com/t/rotor-other-than-brake-rotor/214488/7 "2003-11-21T20:24:51Z")
If the truck is two wheel drive, chances are that the rotor and hub are a one piece assembly. You can’t replace one without replacing the other, and a lot of people just call the whole assembly a “rotor”.