Episode 1624: Tulis, her Civic, and grinding brakes


#1

Caller Tulis said her mechanic “sheared” the wheel bearings on her Civic to fix a grinding noise from the brake area… But the noise later returned, at which the mechanic said he had already “sheared” the bearings as much as was possible, so next step was some replacement parts. So Tulis phoned Car Talk for a second opinion. Ray & Tom said they never heard of “shearing” wheel bearings, and Tulis’ mechanic may be relying too much on prisms and crystals trying to fix her Civic’s brakes.

I’m thinking what the mechanic actually did was “shim” the wheel bearings, and Tulis thought he had said “shear”. And that’s what caused the confusion. What do you think?


#2

Nobody would “shim” bearings. Caller heard “rotors” as “bearings.”


#3

I think I’ve heard of shimming required on rear wheel drive cars with braking problems/noises caused when the axle shaft has too much end-play. Not sure what exactly is shimmed tho, but it might be some kind of spacer applied hear the wheel bearing, which could be described as shimming the bearing. It’s a bit of a reach I admit … lol … especially b/c a Civic is FWD, not RWD.

You could be right, the mechanics was shimming to move the rotor slightly, and decided to describe it as shimming the bearing, which Tulis thought she heard as “shearing the bearing”.

I was thinking also that somehow the bearings and brakes got conflated, and what the mechanic did was shim the brakes, you know those anti-noise shims that come with replacement brake pads.


#4

Mechanic was turning (“shearing”) rotors.


#5

Ah ah, yes, that makes a lot of sense. I’ve never heard it described that way, but it definitely could be. Good idea. “Shear” is correct, but the misunderstanding was rotor vs bearing.