You probably have a chunk of rubber missing out of your reverse drive disc, a new one costs about $16 Fish

Rotor thickness variation is a condition that can be imagined as the two sides of the rotor not being parrallel to each other. This can be caused by a "crushing" of the rotor by the brakes. It can be caused by uneven wear. Or it simply could have developed over time from a combination of forces. This problem is normally felt in the brake pedal by it pushing back at you with a rythm consistent with the current wheel speed. Rotor run-out is often caused by debris (rust) being caught between the new rotor and the old wheel hub, or by improperlly torquing the wheels, which can bend the hub, rotor and wheel. There is always a chance that excessive heat build up from heavy braking without sufficient time for the system components to cool is playing a role as well. This by the way is the most common cause for the report that we often see where a new car keeps having to get the rotors machined. It's not the cars fault, it is how the driver is using the brakes in heavy traffic! We also have rotor delamination, or rusting if you will. This causes a combination of runout and thickness variation issues. Typically rotor thickness variation of .002" is plenty to feel when driving. Otherwise you would have to use a dial indicator, and mark the high and low points on both sides of the rotor to see it. Rotor runout's of .005 or less will normally give no real signs they are present as the calipers of today have sufficient movement built into the system to "follow" the rotor. Between .005, and about .009 you will often feel the pulsation, but quite often you will hear the brake pads "saw" on the caliper supports as they get pushed back and forth. This "saw" is the grunting sound you get on a light brake pedal application as the car moves slowly such as 15mph or less. As I alluded to in the beginning of this response, a good technician does not even need to put a dial indicator on a car where the problem is rotor thickness variation. He/she will feel that right from the drivers seat. However, the technician DOES need to use a dial indicator, and measure wheel runout, then remove the wheel and (for most cars) put the lugnuts back on and measure rotor runout, then measure the front hub runout so that this problem is repaired the first time. Sadly this is one of the times where the good technician that does the job correctly needs to be paid to do so, yet the allure of the "free" brake inspection often prevents them from getting good at it because many are rewarded for being fast and getting the work in and out and as "cheap as possible" which in some occasions turns around and bites them for the effort. For the record, don't do "free" brake inspections, but I fix them.

Hi Toomuch, I'm sorry you could not find what you were looking for. What a bunmmer. We get the ten dollar off coupons, too, and I get so excited! I'm brownbagging the walls, so when we buy two rolls of paper and a little five dollar item, it's like getting one roll free. Love it! What didja end up buying, may I ask? Karen Marie :-)

Hello Jim (jkochan), Nice to see you here. Dave's SW Garden has almost no traffic these days. Everything really splintered after Dave sold the site. I see FishKnees here from time to time but her handle was runs_with_scissors when it was GW, now I've seen her posts (pond pics) as some alphabet soup acronym. Really don't recognize any others, some folks use different handles on different sites so it's hard to tell. I'm getting used to this new format and like it, especially the ease of posting pics. See you around!! Mary