Well after 15,000 miles [on the latest set of PowerStops [3rd set]] it looks like I have solved 50% of the problem by replacing two wheel bearings and hubs back last September. It was always odd that the right front and left rear rotors warped first and twice as severely as the other two in an equal time frame [6,000 miles].Yesterday trued all rotors and the previous bad locations turned out to be the Best ones currently. All in all the warp rate has improved from every 5- 6k to almost 9,000 miles.

The untrue hubs caused by [bearing wear and who knows what torque must have warped the hubs in the early days back in 90-96].Since the side of the road is rougher the right front components usually fail [wear] sooner.

Unfortunately it is labor intensive and parts intensive especially on the rear to correct the problem. Especially since most don't feel or correlate [or understand] the vibration as it transfers to the steering wheel. Most wait to true rotors till the wheel rips from their hand in a high speed brake manuever.

Cost effectiveness depends on how sensitive you are because what you would save in money would just about equal the cost of hub/bearing replacement assumming 5 fewer turning in 100,000 miles [each rotor taken as an individual].

Now if I can only extend the trueing to every 15,000 miles I would have accomplished something.

"Insert from GM Bulletin Number 01-05-001"Anytime a new or refinished rotor is installed on a vehicle, the rotor must have .050 mm (.002") or less of lateral runout. This specification is important to prevent comebacks for brake pulsation. Until now, the only acceptable methods to correct brake rotor runout were to index or replace the rotor or to refinish using an on-car brake lathe.

General Motors has approved a new technology for the correction of lateral runout on new or refinished rotors. This new method is called Brake Align. It will allow the technician to meet the .050mm (.002") or less requirement for lateral runout by installing a specially selected, tapered correction plate between the rotor and the hub. The Brake Align Correction system does NOT require the use of an on-car brake lathe to correct for lateral runout."

http://www.brakealign.com/pages/diagram ... others.pdf

Recently they have introduced part number 402-xx for Q45 at $20 each you could correct for a bad hub, all you need is to measure the runout and order the correct [03 or 06] runout correction plate.

Had a similar experience on another brand of Japanese car. Front rotors were going wobbly at about 10K-12K when they previously would be good to 50K-60K. Went through 3 sets of rotors in 40K. Had they changed the rotor material?

Right front hub surface measured +.004" out of lateral spec. Replaced hub, bearing, converted to KVR rotors with appropriate pads; no more warping.

Not a controlled experiment like Q45tech, but indicative nontheless of how very minute variance from specification can affect disc rotational trueness.

I always thought it must have been overtorqued, but I had witnessed all torquing and knew it was always done correctly. Must have been wear from (curb) side of road or repeated impacts as original hub had about 110K before it showed trouble.

Your 110k is later than my problem first started showing up but I should have put two and two together earlier. As the left front bearing and hub were changed due to minor accident.

Even the new bearing and hub barely meet the oem spec when coupled to the rotor........after index 0.002" at rotor edge is achievable......thats why I am planning on using the shims.

It may be possible to get 0.0005" which might allow a further doubling of miles between cuts to 20k.

The little things are what takes the time to correct. I must have spent 3 years getting the alignment perfect [by replacing everything] after the severe beating I inflicted on the Q in driving 100,000 miles in 3.5 years [not all smooth Interstates].

I emailed BrakeAlign for info and they sent the National Sales Manager and the local rep to T3 [all I really wanted was a sample to try on my Q].

The passenger front was still at 0.0021" [well within spec 0.0028"] so we skipped any work there . The drivers side [1989 hub but new bearing at 70k] was 0.0064" in 20-25 minutes the team had selected the correct shim plate and installed it reducing the rotor runout to 0.0005" [the limit of the dial indicator].10 minutes was occupied in cleaning the hub of corrosion and inside the rotor hat!!!!!! Bright and shiney!!!!!!My car was already on lift wheels off and caliper removed so the timing started from removing the rotor from the hub, cleaning both, reinstalling with conical washers and lugs , setting up dial indicator, measuring, selecting installing BrakeAlign shim plate , reinstalling rotor, mounting caliper, exercising brake pedal to set shim plate, and remeasuring to make sure, then removing the conical washers.........ready to remount tires.

A discussion preceeded this where they stated that GM was ordering 100,000 plates per month for dealers to use on cars.

They recommend dealers charge $59.95 for the first plate and $49.95 for each subsequent one installed.Watched testimonials, nice video. nice people for salesmen, etc.

The above is well in line with our typical $150 per billed hour gross [$68 +$82]. $100 for 40-45 incremential minutes of actual work plus parts [they would cost us $20 each]

The effect was a noticeable improvement in the steering wheel vibration.Every time the rotor is removed for resurfacing a new plate will be required but if this works long term it should double the time between resurfacing so it is cost effective to add $60 to each wheels brake job......not to mention the happiness of less vibration till then!

GM has determined that this process is more cost effective than dealing with an "on the car lathe" not to mention the problems of drilled rotors. Warranty wise I'll bet it saves a lot of hubs and bearings from replacement.

Q45tech wrote:I emailed BrakeAlign for info and they sent the National Sales Manager and the local rep to T3 [all I really wanted was a sample to try on my Q].

Maybe T3 has picked up a rep as trendsetting Infiniti Maintenance among independents?After all its got a great rep in our circles and if you guys test it as good, it will gain acceptance in many places?Or am I overestimating the power of Internet word of mouth?

Fred...

I do point out the two forums I help moderate in all my emails since the other one has close to 11,000 members but has little Q/J technical activity my focus is here.I can assure you Nissan reads every post [here and there] and I get lots of grief but no public disagreement as facts are facts.

Q45tech wrote:I do point out the two forums I help moderate in all my emails since the other one has close to 11,000 members but has little Q/J technical activity my focus is here.I can assure you Nissan reads every post [here and there] and I get lots of grief but no public disagreement as facts are facts.

:bowdown --->Q45tech

palmerwmd wrote:
:bowdown --->Q45tech

too funny...

Yeah, when the dealer said they wanted to true the new rotors on the car to allow for any hub imperfections, I thought the idea was nuts (for new rotors) and hence changed the hub and bearing (plus rotor brand and pad brand).