2002 F50 Steering wheel 'shake'?????? (also need advice on 22"s)

[britinmn]

Hi!!As a ‘new’ F50 Q45 owner I’ve been ‘lurking’ around the forum for the last few weeks gathering as much info as I possibly could.

I have an ’02 with Sport and Sunshade packages, 69K miles – Desert Platinum with tan leather … absolutely beautiful condition throughout, and just waiting for the weather to warm up here a little so that I can get a few coats of Zaino on her

Thanks to all the people who post, and respond, as so far I’ve managed to answer all of my questions/issues …. That is except these 2 questions/issues……

First question:Car has a shake/vibration in the steering wheel – most noticeable between 50-65mph. I originally thought that it was a warped rotor and/or tire/wheel balance issue. (had other symptoms of warped rotors, i.e. significant brake pedal vibration when braking hard).

So first off – I had the front brake rotors turned and installed new pads all round – still have the steering wheel vibration, very, very slight vibration in the brake pedal when braking hard.

Next step - I had the very worn Michelins replaced this week with a new set of Yokohama YK520s (seemed to be a good choice for a daily driver up here in MN). Noticed that the Yoko’s seem quieter than the Michelins, with no real change in ride quality. …. But the steering vibration is still there …..grrrrrrrr…

Then …. Took the car to a local shop that I trust – had the wheels and new tires re-balanced, and had them check out the suspension/steering. Report came back saying that they could find no problems with the suspension/steering, and after the re-balancing there was marginal, if any, improvement.

So my question is …. Any ideas what could be the cause?? From my research it appears that these cars are very sensitive to any warping of the rotors… and although I had them turned very recently, I’m not 100% positive that this is not the cause but I also don’t want to spend $200-300 on new rotors if I don’t really need them…. (and incur the subsequent wrath of my wife! Spending $800 on tires and $300 on rotors to NOT fix a problem is not a recipe for marital bliss!)

I haven’t had any experience with my local Infiniti dealer yet, so I am a little skeptical of having them look at the car without me having a good idea of what is causing the problem. (bad and VERY bad experiences with other manufacturers dealers has left me a little ‘gun shy’)

Any advice on this would be GREATLY received, as quite frankly a) it is driving me NUTS! And b) this small ‘niggle’ is amplified by the rest of the car just being so damn good! This is probably the best all round car I have EVER had the pleasure of driving, and when you consider just how cheap these cars are to buy used now, it’s a definite bargain!!

Second question:For those of you running 22” rims on your F50 – what size tires are you running to avoid fitment issues?? I have a set of chrome 22” rims with 265/35 Pirelli’s that I might take off of the car they are on and put on the Q … not sure what offset the rims are so that might cause other issues, but before I tried I thought I’d seek out the experts to see if this tire will even fit before I start playing in the garage this weekend

Thanks in advance for all the help guys!!

[StarPD]

I'm thinking possibly wheel bearings or shocks.Possibly a bent or out-of-round wheel?Bad tread belt in a tire?

The vibrations you now feel in your brake pedal could just be transmitted from the problem and not be the problem itself.

Try temporarily replacing the wheels with known good ones to see if it changes.

Anyone else?

[maxnix]

Known problem on F50. JasonB can comment further.

If you don't have Michelins on OEM or better (lighter and stronger) wheels, installed, balanced and aligned by an excellent technician you will have a problem.

22 and you will see many more problems due to unspring mass increase, different spring rate of the tire sidewalll.

[britinmn]

Thanks guys, appreciate the input !

Current wheels are the OEM 18" sport package wheels. There is no visible damage to the wheels, and now I've had them balanced at 2 different shops, so if there were any out of round issues I would think it would have been noticed?Just swapped old tires for new, so I hope I didn't have a bad tire replaced with a bad tire .... anybody know of a way of confirming if a tire has a bad tread belt or other issues?

Unfortunately I don't have any other wheels that will fit (other than possibly the 22's) so that kinda limits me from isolating the problem a little further - Is it worth swapping out the rotors just in case? Has anybody had this cure a similar problem?

Thanks again guys!!

[maxnix]

I've had them balanced at 2 different shops, so if there were any out of round issues I would think it would have been noticed?

On a Hunter GSP 9700? http://www.gsp9700.com/

They would spin up the wheels first. Runouts measured. Same for rotors while on the car.

Michelins?

[Rex]

Is the vibration ...

In the steering wheel or the seat?

More noticable under accelration?

Even more noticable under the same speed in lower gear (higher RPM's)?

Under breaking?

And finally, can you rotate the tires from front to rear or side to see and see if there is any change?

[StarPD]

Thanks guys, appreciate the input !

Current wheels are the OEM 18" sport package wheels. There is no visible damage to the wheels, and now I've had them balanced at 2 different shops, so if there were any out of round issues I would think it would have been noticed?Just swapped old tires for new, so I hope I didn't have a bad tire replaced with a bad tire .... anybody know of a way of confirming if a tire has a bad tread belt or other issues?

Unfortunately I don't have any other wheels that will fit (other than possibly the 22's) so that kinda limits me from isolating the problem a little further - Is it worth swapping out the rotors just in case? Has anybody had this cure a similar problem?

Thanks again guys!!

I'd at least try the 22s. That would eliminate the wheels/tires from the equation. If nothing changes then, you could have the rotors spun up and checked for remaining warpage.

After that, I think you're left with considering wheel bearings or shocks.SOMETHING is wrong, and you will have t isolate the problem by eliminating possible sources one at a time.

[maxnix]

.. you could have the rotors spun up and checked for remaining warpage.

Don't need to be spun except by hand to check for runout.

[StarPD]

Don't need to be spun except by hand to check for runout.

Okay, spin 'em up by hand then. I just like to see them doing 100,000 RPM.

[britinmn]

Thanks again for everybody's input - to answer some of the questions:

Vibration is felt through the steering wheel - there is noticeable steering wheel movement. If I hold the steering wheel really lightly you can see the wheel move maybe 1/2" or so. (that may be an exaggeration on my part as I haven't actually measured it!)

No noticeable change in the vibration based on engine load or RPM, just speed.

Haven't noticed any change in the level of vibration in the steering while braking - but I'll definitely check that more closely tonight as that was not something I'd checked.

I'll change the rear wheels with the fronts this evening - if no change I'll see if I can squeeze the 22s on to try to further eliminate the wheels/tires.

Then I guess the next step would be to have the rotors re-turned/replaced to try to eliminate them.

Then it sounds like the thoughts are that it's probably wheel bearing/suspension (strut) related,. (I had considered tie-rods also, but it doesn't feel/sound like tie-rod issues I've had in other vehicles) Anything particular on the suspension other than struts that comes to mind? I imagine working on the switchable suspension (which I've already come to love!) is not an inexpensive thing....

I'll let you all know how things progress over the weekend... fingers crossed!

[Jesda]

Steering wheel shimmy at 55mph, on any car, most often is warped rotors or wheel/tire balancing.

Have the wheels road force balanced. Your dealer should know what that is. I imagine the rotors have plenty of meat at this mileage and can still be turned instead of replaced.

[maxnix]

Michelins?

[xerexabante]

Classification:BR00-005b

Reference:ITB00-024b

Date:August 30, 2004

ALL INFINITI; BRAKE NOISE/JUDDER/PEDAL FEEL DIAGNOSIS AND REPAIR

This bulletin amends ITB00-024. This version amends the Brake Judder Repair information.

Please discard all paper copies of the earlier versions.

APPLIED VEHICLES:All Infiniti

SERVICE INFORMATION

^ This bulletin is to assist you in responding to customer questions about brake operation and provides diagnostic and repair information for each item listed if any should occur. ^ Most brake incidents fall into the following categories:

a. Brake Noise: A squeak squeal clunk or groan that occurs when the brakes are applied or released. b. Brake Judder: A vibration that can be felt in the vehicle steering wheel or brake pedal when the brakes are applied. c. Pedal Feel: The effort needed to operate the brakes is too high or too low.

SERVICE PROCEDURE

1. Verify the condition by road testing the vehicle with the customer. 2. Determine the specific brake incident based on the description in the Service Information above. 3. Follow the appropriate repair procedure(s) listed on the following pages for your specific incident.

BRAKE NOISE

^ Brakes can make a range of noises when applied or released. Some noises are normal and no repair action should be taken. ^ Use the following descriptions to identify the specific type of brake noise and the appropriate repair:

Squeak noise when the brakes are cold:

^ Usually occurs during the first few stops in the morning. ^ This is a normal condition. No service action is necessary

Squeak noise with the brakes at normal operating temperatures:

^ Refer to technical bulletins specific to the model of vehicle regarding this incident. ^ If there are no bulletins for the car you are working on install OE type pads using the information listed under Brake Service in this bulletin and the appropriate Service Manual procedures.

Notes about brake pads and brake noise:

Original Equipment (OE) brake pads are installed on all current Nissan vehicles at the factory.

^ The OE pads use a Non-asbestos Organic (NAO) compound. The NAO material provides state of the art resistance to squeal noise. ^ These pads are available as service parts and must be used if replacing brake pads under the terms of the Nissan new car warranty.

Key Value brake pads are also available as a high quality service replacement part at a very attractive price.

^ These pads use a semi-metallic compound similar to the material used in Nissan OE pads prior to the introduction of the NAO compound. ^ Key Value semi-metallic pads offer excellent braking performance but do not offer the same level of noise resistance as the OE-NAO pads. ^ Service customers have varying sensitivity to brake noise and the individual customer must decide which product best suits his or her requirements balancing price and noise resistance. ^ Make sure the Service Advisor adequately explains the differences between Key Value brake pads and Nissan OE-NAO brake pads to the customer when discussing brake service.

Loud continuous squeak/squeal noise:

^ Occurs with or without braking. ^ This is a normal brake function. It occurs when the brake pad wear indicators contact the rotor. ^ It indicates the brake pads are worn out and need to be replaced. Install new brake pads using the information listed under Brake Service on page 6 of this bulletin and the appropriate Service Manual procedures.

Groan noise when slightly releasing the brakes after coming to a stop:

^ This is sometimes called "creep groan" ^ It is a normal condition. No repair or service is necessary

Groan noise during stopping:

^ Usually caused by glazing of the rotor's surface as a result of heavy or frequent braking. ^ Refer to technical bulletins specific to the model of vehicle regarding this incident. ^ Replace the brake pads, then resurface the rotors and finish them with sand paper. Refer to Brake Service for additional detail.

Single clunk noise from front suspension when applying the brakes:

^ The noise is a result of the brake pads shifting in the direction of rotor rotation when the brakes are applied. ^ Can be duplicated by lightly touching the brake pedal. ^ If the brake pedal is pushed hard, the noise is less likely to occur. ^ Make sure the brake pads and pad hardware (shims, springs, clips, etc) are installed correctly. ^ Refer to ASIST for vehicle specific brake service information. ^ Refer to Brake Service for additional detail.

Multiple clunk noise and/or pedal pulsation that occurs only one time after the engine is started:

^ This is a normal ABS Self Check noise. No service action is necessary. ^ The vehicle's ABS system performs a self check. On some models, this self check occurs with the first application of the brakes after the engine is started. On other models, the self check occurs the first time the vehicle reaches 5 mph after the engine is started.

Rear Brake Squeal:

^ Usually due to an accumulation of brake dust and dirt between the pads/shoes and rotors or drums. ^ Clean all dust and dirt from the brake shoes backing plates and related components. WARNING :Brake dust may be hazardous if inhaled. Refer to the Service Manual (ESM) for brake dust precautions and use approved brake cleaning equipment.

^ Refer to ASIST (Service Bulletins and ESM) for correct installation and lubrication of brake pads caliper parts and hardware CAUTION o not get grease on the brake pad friction surface.

BRAKE JUDDER

^ Brake Judder is caused by rotor thickness variation and/or rotor run out.



Rotor Thickness Variation: When the inner and outer surface of the rotor are not flat and not parallel the brake pads will travel in and out as they follow the low and high spots on the rotor (see Figure 1).



Rotor Run Out: If the brake rotor is not true to the hub center the brake pads contact one point on each side of the rotor with each wheel rotation even if the brakes are not applied. Over time this point contact will cause the rotor to wear more in these areas and cause rotor thickness variation (see Figure 2).

^ This motion of the brake pads is transferred through the caliper pistons and is felt in the brake pedal as a pulsation. In severe cases it can also cause a back and forth oscillation in the steering wheel.

Vehicle Storage:

^ If the vehicle is not operated for periods of time the area of the brake rotors not covered by the brake pads will rust. ^ The friction characteristics between the rusted and un-rusted areas of the rotor braking surface will be different. ^ This difference may cause brake judder at low and/or high mileage even after the rust wears off.

Lug Nut Overtorque:

^ Another contributor of brake judder is lug nut overtorque. This can occur if the lug nuts are over tightened especially with an air impact wrench.

Brake Judder Repair

^ Brake judder incidents must be corrected by turning the rotors with a ProCut(TM) PFM series On-Car Brake Lathe. ^ Refer to ITB04-038 for additional information on using this lathe. ^ If the rotors are replaced make sure you index them to the axle hub to ensure minimum runout (see Rotor Indexing).

PEDAL FEEL

^ Some customers may say that the brake pedal feels too high or low when applying the brakes. ^ This may indicate the brake system needs service or it may be the result of the customer comparing the feel of the brakes in a new car with the feel of the brakes in a previous car. ^ Road test the vehicle with the customer. Compare brake operation to a know good vehicle and determine if brake service is necessary. If so refer to the following service items:

a. Inspect the brake calipers and make sure they are correctly installed and sliding freely. b. Inspect the front and rear brakes and make sure the brake pads and/or shoes are properly installed. c. Bleed all air from the brake system. d. Make sure the brake pedal stroke and free play are adjusted correctly. Refer to the BR section of the appropriate service manual. NOTE :Use Essential Tool J-46532 (Brake Pedal Height Tool) for brake pedal height check and adjustment. This tool is available from TECH-MATE.

BRAKE SERVICE

To ensure a high quality brake service be sure to:

1. Finish rotors properly.

^ This is one of the most important aspects of preventing and eliminating brake noise. ^ Use the ProCut(TM) PFM series on-car brake lathe. It has been chosen as the approved tool for rotor resurfacing (refer to ITBO4-038 for additional information). 2. Correctly install pads and shims. IMPORTANT :Correct installation and lubrication of brake pads and all caliper parts and hardware is essential for proper brake operation and will help dampen noise-causing movement and vibrations.

^ Refer to ASIST (Service Bulletins and ESM) for correct installation and lubrication of brake pads caliper parts and hardware. CAUTION o Not get grease on the brake pad friction surface. 3. Perform the following post-installation checks.

^ Confirm that brake pads fit snugly in the calipers. Replace worn components as necessary. ^ Test drive after repairs and burnish the new brakes. This will influence brake performance including noise.

a. Drive the vehicle on a straight smooth road at about 30 mph (50 kph). b. Use medium brake pedal/foot effort to bring the vehicle to a complete stop from about 30 mph (50 kph). Adjust your pedal/foot pressure so that the vehicle stopping time is 3-5 seconds. c. Cool the brake system by driving at about 30 mph (50 kph) for approximately one minute without stopping. d. Repeat steps 1, 2, and 3 ten times to complete the burnishing process. 4. Follow-up to ensure customer satisfaction safety and proper brake performance.

^ Confirm the procedures described in steps 2 - 4 above have been strictly followed.

ROTOR INDEXING

When installing a new rotor a rotor that has been surfaced off the car or a rotor that has been removed for any reason use the following indexing procedure to ensure the minimum amount of rotor run-out.

1. Make sure the rotor is fully contacting the hub. Clean the rotor-to-hub surface if it is rusty. NOTE :For cleaning the hub surface specifically around the wheel studs it is recommended to use the Wheel Hub Cleaning Kit # J-42450-A which can be ordered from Nissan TECH-MATE. 2. Install the rotor and all lug nuts. Tighten the lug nuts to 40 ft-lbs (for this indexing process only). 3. Place a reference mark on the rotor and hub.



4. Measure rotor run-out with a dial indicator (see Figure 3). If the run-out is above 0.001 (0.03 mm) continue with step 5. 5. Remove the lug nuts and shift the position of the rotor one lug clockwise then reinstall the lug nuts and torque to 40 ft-lbs (again for this indexing process only).

^ Repeat step 4 and 5 until the rotor is positioned with the least amount of runout. 6. After you find the position with the least amount of runout if the runout is still more than 0.001 (0.03 mm) you'll need to turn (resurface) the new rotors using the ProCut(TM) PFM Series on-car brake lathe.

CLAIMS INFORMATION

Please reference the current Infiniti "Warranty Flat Rate Manual" and submit your claim(s) using the Operation Code (Op Code) or combination of Op Codes that best describes the operations performed.



Disclaimer



© 2007 ALLDATA LLC. All rights reserved. Terms of Use

[xerexabante]

Steering/Body - Vibration at highway Speed Notes Classification: FA01-001

Reference:ITB01-034

Date:June 1, 2001

2002 Q45; STEERING/BODY VIBRATION AT HIGHWAY SPEED

APPLIED VEHICLE(S): 2002 Q45 (F50)

SERVICE INFORMATION

If a customer complains about steering and/or body vibration while driving (without braking) at speeds between 60 and 70 MPH, the cause(s) may be:

^ Road input (road surface imperfections) ^ Out-of-balance front or rear tires/wheels ^ Insufficient steering rack sliding force adjustment ^ Tire flat spotting ^ Excessive tire Radial Force Variations (RFV)



PARTS INFORMATION

CLAIMS INFORMATION



Submit a Primary Operation (PO) line claim (1) using the claims coding table shown.



© 2007 ALLDATA LLC. All rights reserved. Terms of Use

[xerexabante]

Steering/Body - Vibration at highway Speed Notes Classification: FA01-001

Reference:ITB01-034

Date:June 1, 2001

2002 Q45; STEERING/BODY VIBRATION AT HIGHWAY SPEED

APPLIED VEHICLE(S): 2002 Q45 (F50)

SERVICE INFORMATION

If a customer complains about steering and/or body vibration while driving (without braking) at speeds between 60 and 70 MPH, the cause(s) may be:

^ Road input (road surface imperfections) ^ Out-of-balance front or rear tires/wheels ^ Insufficient steering rack sliding force adjustment ^ Tire flat spotting ^ Excessive tire Radial Force Variations (RFV)



PARTS INFORMATION

CLAIMS INFORMATION



Submit a Primary Operation (PO) line claim (1) using the claims coding table shown.



© 2007 ALLDATA LLC. All rights reserved. Terms of Use

[phatyak]

Noob here. Been lurking for a while and figured it is time to break out of my shell.

First question:Car has a shake/vibration in the steering wheel – most noticeable between 50-65mph.

I am experiencing this same vibration on my F50 immediately after having the brand new tires mounted and balanced along with the rear bearing/hub replacement and an alignment. I do not experience the vibration in the brake pedal during braking, unless I brake firmly in the 50-70 speed range, and then the vibration is only moderate and likely just an amplification of the original vibration. Any other time I have no vibration from braking, so I don't think it is my rotors. The vibration gives feedback in the steering wheel but not in the driver's seat. However, the passenger seat seems to shake more than the driver's does.

A shop just down the road from me is listed as having a GSP9700. I am considering having my front wheels road force balanced to see if that solves the problem. Honestly, I am concerned that there may be a problem with a front hub/bearing on the passenger side (the back on the same side was bad), but since the vibration is mainly between 50-70 I am hoping the shop that mounted my tires didn't do a good job of balancing afterward.

Brit, I look forward to your post about what you found out this weekend. I agree with you, this car is rock solid everywhere else and this annoying vibration really stands out as harmful to what would otherwise be an extremely fulfilling driving experience.

[phatyak]

Thanks for these posts Xerex. Question for those much more knowledgeable than I . . . what does this mean:

"Insufficient steering rack sliding force adjustment."

I get the general idea, but not sure how this would occur.

Based on this information, it appears as though my problem is most likely poorly balanced wheels by the tire shop.

[Jesda]

The 2000-2005 Cadillac Deville (with a similar front suspension setup) suffers from the same problems. The final solution, unless rotors are warped and they are the cause, is a set of Michelin Symmetry tires and road force balance.

[britinmn]

Hi again everybody!!Good news (at least for my particular problem) I tried the simplest fix first - swapping the rear wheels with the front, and made sure each tire was at 33 PSI - and a 99% improvement !! Yippee!!! Is it perfect, no... but very, very close .... now I'm a little concerned as to why the shop that did the second balance didn't try this... ummhh.... something to chat to them about tomorrow

When I had the front wheels off the ground I also double checked the wheels for any 'play' and couldn't detect any, everything felt rock solid.... visibly inspected the wheels, tires, suspension components for any signs of damage/wear and everything looked ok.

I guess the next step is to find a local tire shop that does the 'road force' balancing - as I'm still not happy that one of the wheels/tires seems to have a problem, even though now it's on the rear... but that can wait until next week, or until I get enough cash in my wallet so that the wife doesn't find out!

Phatyak - hope this helps you a little - if you get the chance to 'road force' balance your new tires before me I'd be very interested to hear your experience. What tires did you go with by the way, and why? I went with the Yoko's beacuse of the need for a good all season tire with long treadwear and low noise. I'm using my Q as a daily driver for the next few years, (70 mile a day commute) so if everything goes according to plan I'll be keeping her until well over 200K. Hard to think that a premium luxury sedan that puts out 340HP is a viable 200K daily driver! But to be honest, if I have to invest the purchase price again in maintenance over the next few years this will still be the best car deal ever!

A big thanks to Xerex for that detailed info, and to everybody else who has contributed to this thread - it's great to know that there are so many VERY knowledge people here to help, especially when you consider how relatively rare these cars are!

I didn't get a chance to try the 22s tonight as I managed to resolve the issue so easily... I may still give them a try this weekend to see if they fit, how they look, and what kind of degradation in ride quality they give - but probably not a viable long term proposition for me as I LOVE the way it rides on the 18s.

Thanks again everybody!!

[phatyak]

Thanks for the update Brit. I may try your temporary solution as well because it will probably be next weekend before I can get the balance done. Doesn't solve the problem, but might make it less frustrating on the commute back and forth to work (80 miles for me).

I went with the Bridgestone Potenza RE960AS Pole Positions. Tire Rack reviews had them rated highest for the 245/45 18 size and the cost was very reasonable. Happy with the tire so far: very little road noise, good responsiveness, corners well, and the car feels planted on the road now, 400 treadwear on Z speed rated tires with a 100W XL load rating. 35 pounds of pressure in them made a big difference over the 33 that is recommended by Infiniti. I only have about 250 miles on them, though, so I am reserving judgement until this balancing issue is resolved and I get about 10k of wear.

I am getting started working through changing all the fluids on the car right now, so that along with the vibration issue will keep me busy for the next several weekends I am sure. I'll let you know if swapping the front and rears works as a temporary measure for me as well.

[xerexabante]

Anytime. I got help here and i would like to help back. I hope it answers most if not all queries about steering shakes. Good luck and may ALL our Q's be health as we are. If any one need more help please email me at:[email protected]

[phatyak]

I swapped the front and rear wheels. There is some improvement but it's still not just right. Makes it more liveable until I get the alignment done, though. I checked the bearings while I did it and everything seems fine.

Thanks for the idea, Brit.

[BadQ45t]

My mechanic in LA does the load balancing and there is NOTHING that compares to having it done that way. It is farily time consuming so your likely to pay double of what a regular balance is but worth it. I had a local mechanic mount my new M45 rims on Y33 and he did have the most advanced Hunter system, but when I get the car down to LA where guy does the load balance I will invest in it for sure, totally worth it with bigger rims.

[maxnix]

I went with the Yoko's beacuse of the need for a good all season tire with long treadwear and low noise.

Only Yokohamas that would work on a Q45 for very long are the AVS dB S2.

Others are simply not strong enough construction. Neither are any Yokohamas made to the standard of Michelins. They are servicable, but that is about it.

The benefits of using the Hunter GSP 9700 is determined by the experience of the operator. All Infiniti dealers were required to install them a couple of years ago. An experienced operator can do a good a job with an earlier machine as the road force balance is limited in range and cannot totally replicate real world tire loadings. It is a tool, but it must be used wisely to obtain the desired results.

[PIONEER]

Guys if you recall, my 02 F50 had the same nightmare shake before I sold it.

I had the stock wheels/tires and there was just a Slight, Very slight vibration at 80-90+.

Then I got 20" wheels/tires and Changed the Rotors to JasonB's slotted rotors. The problem started bad at that point.

I was then told the load rating on the tires was wrong for the Q. so I got 97 and 99 Y load rating tires. NO difference.

I put a difference set of Infiniti wheels on it, the problem got a little better.

Then turned out the left front Control arm balljoint was damaged.

Changed Control arm, problem got a little better.

Then I got mad and sold the car.

Problem went away for good.

Today when I look back, I think the problem was in the Rotors b/c thats the only thing we didn't change on that car.

[phatyak]

PIONEER, thanks for your comments.

Did you have the shimmy all the time or only when you were braking? I thought I could rule out the rotors since I don't have any problem with braking, but now that you have posted I am wondering.

[Q45man1]

I had the same experience mid of last year when the steering shake. My tire guy rebalanced it using Hunter GSP9700, and also found out that one of the rim is slightly bent. Replaced it with my full size spare. Also replaced all tires with Dunlop sport maxx with 100 load index and 34psi air pressure. Problem went away.

[StarPD]

Only Yokohamas that would work on a Q45 for very long are the AVS dB S2.

Others are simply not strong enough construction. Neither are any Yokohamas made to the standard of Michelins. They are servicable, but that is about it.

The benefits of using the Hunter GSP 9700 is determined by the experience of the operator. All Infiniti dealers were required to install them a couple of years ago. An experienced operator can do a good a job with an earlier machine as the road force balance is limited in range and cannot totally replicate real world tire loadings. It is a tool, but it must be used wisely to obtain the desired results.

I used AVS dB on my '94 Q45t until they were discontinued, then used the AVS dB II, V rated. They are surprisingly good tires. Not Michelins, but quiet, good response, good traction, and important to me, controllable. They break loose fairly gradually under power on the rear, then hook up fairly gradually when drifting corners. Not quite as smoothly as Michelins, but better than most. I used to be able to make a particular15 MPH hairpin at 45 MPH swinging the back end around the front, grinning from ear to ear. Ride was very good too. All in all, it's a hard tire to beat, especially for the price.I wouldn't hesitate to recommend it.

So far, the 18" RE050A Pole Positions on my 2005 Q45 seem to be as good or better on the same turn, but wife doesn't like it, so I haven't taken it to the limit. One day when she's not with me, I'll push it a little to see how well they do.

[Jesda]

Michelins aren't the best anymore. Lots of competitors have caught up, including Bridgestone. Especially in OEM applications, some Michelins can be junk.

[kev1n]

I had the same issues when I bought my car,

step 1, I replaced all the pads and rotors. marked improvement, but there was still some amount of vibe at about 80 mph. Step 2 , I replaced the OEM rims and tires with 19's and that eliminated the entire problem.