Reason for one rotor being hotter then other?

[sasha055]

Hi,
For the last couple of months I'm trying to get rid of vibration on my car (2000 Base 72K miles).

I changed brakes/rotors, rear wheel bearings, balanced and aligned the wheels.. and Yet at 50+ mph it shakes me like a british nanny

Yesterday I decided to check temperature on rear boots to see if bearings heat evenly.. and to my surprize temp on left rotor was 110 deg and on right rotor 95deg

Is it normal or something is going on?

It feels like vibration is coming from rear left.. it's feels like lug nuts are touching parking brake or something is touching something there I just cann't figure out what..

Thanks
Sasha

[Lil bastard]

I don't see a problem. A mere 15 degrees (especially in the 100 degree range) isn't a big deal and doesn't point to anything in particular.

If you had a caliper or pad sticking, it would certainly be a bigger difference than you're seeing. One bearing may run a little hotter than the other due to different amounts of grease, different loads, etc.

I chalk it up to errors in methodology.

I assume you used a Pyrometer to check temps, likely an IR Pyrometer at that.

Well, you probably checked one side, then the other. If you checked the left 1st, then the right had additional time to cool.

Also, there is an innaccuracy in every instrument. Add to this that the Pyrometer can be fooled. If you had a light source on one side such as a floodlamp, halogen or even the sun, you're likely to get slightly different readings.

You're trying to pinpoint a variable speed vibration. These are almost always due to a tire/wheel imbalance. Have you roadforce balanced the tires/wheels? When?

If so, have you weighed them? How old (miles) are your tires? Are all 4 tires the same 'age'? When was your last alignment? 4-wheel alignment?

Alignments are not mileage dependent. Get an alignment, hit a pothole 1 mile away coming from the alignment store, and you need another alignment, or you'll have a vibration due to the differences one side to the other because of the pothole.

I don't think your issue stems from differences in temps one side to the other.

Cheers!

[thstone]

+1 on not being temp related.

Here are my Top 5 next places to look:

1. Tires - get them balanced while on the car and tell the tech that you're having a vibration problem so he can be careful to do a good job.

2. Suspension - possibly a bad bushing or something that is allowing a little free play to create a vibration.

3. Alignment - previous post had a great description of issues related to alignment.

4. Parking brake - inspect and adjust it so its completely loose and see if this helps.

5. CV Joints - check for wear/play.

[sasha055]

Thanks Everyone for advice.

I'll be bringing it to my mechanic soon (again). First time he couldn't figure out what the hell is wrong with the car.

I'll show him the list of things to check.

Sasha