Steering wheel vibrates when braking

[jarhead1]

Hello to all. I have recently started noticing a trouble...Pathfinder 2001. while driving , 0-90 no trouble straight as an arrow no noises,shakes, rattles or rolls...But when braking between 60-70 mph I have noticed that the steering wheel is vibrating/shaking ???

vehicle stays straight while braking, and it does not happen or is not noticeable at lesser speeds....???

any ideas ? thanks for listeningSteve

[Nismo_Freak]

Runout on the rotors... aka warped rotors.

Possible that you have a build-up of pad material on the rotor as well but this typically happens only in cases where you apply alot of thermal load on a pad.

Time to go get the rotors cut, and now would be a good time to go ahead and change pads. That way you get proper bedding and wear between the two items since they are both wear items.

Also, odds are you need to flush your brake fluid (this should be done once a year ideally) as well. Brake fluid is hydrascopic meaning it absorbs water from the atmosphere. Dot 3 fluid is more hydrascopic than a Dot 4 fluid usually. Dot 4 fluid also has superior boiling temps compared to Dot 3.

DO NOT get Dot 5 fluid.

Dot 5.1 fluid is ok, as it's designed primarily for ABS systems AFAIK.

[cowboyrps13]

do pathfinders have T/C rods? :oface the same thing happened in my 240 but when i replaced those it went away!

[Nismo_Freak]

do pathfinders have T/C rods? :oface the same thing happened in my 240 but when i replaced those it went away!

High speed vibrations aren't usually a result of T/C rod bushings.

If it was, it'd do it at just about any speed.

[cowboyrps13]

he said only when braking though, thats when mine happened and the T/C rods cured it. my wheel never vibrated under normal driving.

[Nismo_Freak]

he said only when braking though, thats when mine happened and the T/C rods cured it. my wheel never vibrated under normal driving.

I ment all the time as in when ever he braked form a lower speed, higher speed, etc.

The tension rod bushing doesn't differentiate speed since nothing is accelerated at speed. The rotor however is...

[cowboyrps13]

but arent the tension rods affected by the tension put on them. so at different speeds different tensions would be put upon the bushings. hence different reactions at different speeds?

[jarhead1]

Thanks much ! I may also add that it never shakes other than when braking 70-60-55 in this area only, and that about 1,600 miles ago(my last oil change) I had premium brake pads installed (but not ceramic) but never experienced this before this.

Any recommendations on aftermarket rotors ??

[cowboyrps13]

if brembo makes them for your truck then i suggest their blanks(no crossdrilling or slotting) excellent aftermarket rotors.

[Nismo_Freak]

but arent the tension rods affected by the tension put on them. so at different speeds different tensions would be put upon the bushings. hence different reactions at different speeds?

The tension rod's duty is to prevent caster change. At higher speeds yes there is more force, but not to the effect of a 14 lb. rotor spinning as fast as the wheel.

[cowboyrps13]

then why did T/C rods solve my problem from the same speeds he is having problems with? i have no vibration at all any more since ive replaced them.

[Nismo_Freak]

Thanks much ! I may also add that it never shakes other than when braking 70-60-55 in this area only, and that about 1,600 miles ago(my last oil change) I had premium brake pads installed (but not ceramic) but never experienced this before this.

Any recommendations on aftermarket rotors ??

Sounds like possibly a deposit of pad material on the rotor face. Inspect the rotor for dark spots, if you notice a shiney metallic look (looks glazed over) then you can try lightly wet sanding the disks to remove the glaze and excess pad material.

[cowboyrps13]

ive also been told to replace/resurface the rotors and pads at the same time, i dont know if you did that or not and i dont know how true that is, just what ive been told by some people i work with. so if you didnt do either of those, possibly it could be a pad/rotor mismatch. i wish i was 100% sure of what i just said though :oface

[SmithSR]

I think Freak sticks with the idea of a warped rotor because 99% of all cars/trucks/motorcycles that suffer from vibration when braking can be fixed with replacement or machining of the F rotors.

If the T/c rod busings are junk, or factory OEM, well... ain't never been a better time than right now... to replace them as well. Call it a tune up for the front chassis.

[Nismo_Freak]

then why did T/C rods solve my problem from the same speeds he is having problems with? i have no vibration at all any more since ive replaced them.

Like Smith said, I'm betting on the more prominant issue. Plus his Pathfinder rests on a body on frame design like a truck so problems like that typically aren't as pronounced.

Easiest method to determine the problem is to see if you get vibration in the brake pedal. If so then the brakes are at fault as the runout is causing hydraulic pressure to rise suddenly causing pedal pulsation.

[Nismo_Freak]

ive also been told to replace/resurface the rotors and pads at the same time, i dont know if you did that or not and i dont know how true that is, just what ive been told by some people i work with. so if you didnt do either of those, possibly it could be a pad/rotor mismatch. i wish i was 100% sure of what i just said though :oface

I explained briefly why in my previous post.

Basically you have two items that wear together. They will create a wear pattern. If you replace just the rotors then the pads will wear the rotors unevenly because of the different wear patterns trying to equal out.

[Nismo_Freak]

then why did T/C rods solve my problem from the same speeds he is having problems with? i have no vibration at all any more since ive replaced them.

The problem isn't the same is the reason. One of the things you learn with working on cars for a living is that just because it sounds like a lion, doesn't mean it's always one.

Two problems can produce the same resulting vibrations... but it's the subtle differences that pinpoint the problem.

[cowboyrps13]

i see what your saying with the differences between brakes being warped and the t/c rods being bad. and thanks for confirming my little brakepad rotor mismatch thing i mentioned. the only reason i stood up so firmly for the t/c rods being the problem, he mentioned the steering wheel was shaking and only shaking during a certain speed. it doesnt pull when he puts the brakes on(i think i remember a coworker telling me warped rotors can pull, not too sure though). when jarhead posted that he replaced the pads and not the rotors that made me think otherwise. that it probably was the rotors, which i mentioned a little later. thanks for clearing some stuff up for me though :thumbup

[Grant@tirerack]

If the vibration fades as you hold down the pedal, it's likely just an incomplete transfer film on the rotor. If it's constant, the rotor is warped. We sell a lot of rotors for these Pathfinders. The brakes are very small for the vehicle weight. I will second the opinion on checking your fluid as well. If it looks like coffee or tea, it's time to change it. It should be clear.

[jarhead1]

Hello to all, I decided to go to my "Mech" for an oil change and dropped this on him, he put my " F-4 Phantom" up on the lift and commenced to checking out stuff : shaked rims for looseness, spun tires, checked pressure, checked linkages, then took off tires and said he was going to sand off some shining area on the left rotor , he put everything back together and said that if it happened again that the rotors would be replaced aswell as the pads.Well I took it for a drive but due to traffic and weather conditions was not able to get passed 75-80 mph where I felt safe for me and my fellow drivers. I applied brakes a couple of times and it did not do it-at least not yet, so I went back and thanked him and he said it is too early to tell to give it about 100-150 miles or two weeks. so I will give notice in about 2 weeks... thanks to everyone and will keep informed.