Intermittent vibration/shudder when braking at highway speeds

[txgringo]

I have an 08 GX470 and I'm experiencing intermittent vibration/shudder when braking at highway speeds. It never happens when just driving (only when brakes are applied), and it never happens at lower speeds (e.g. under 50).

Since it is only happening while braking, conventional wisdom would point to an issue with rotors (warped or uneven wear from L to R) or possibly a sticky caliper grabbing harder on one side than the other. However, since it is not happening 100% of the time, I don't think the rotors would be the issue and since it doesn't happen at lower speeds I think a sticky caliper is unlikely.

Anyone have advice on what to check for this? Thanks in advance.

 

[unklwedy]

Steering stabilizer, loose wheel bearings, loose nut behind the wheel, loose caliper,...

Does vibration feed back thru steering wheel ?

 

[txgringo]

Does vibration feed back thru steering wheel ?

yes, I can feel it strongly in the steering wheel. Could a worn bearing on the UCA cause this?

 

[unklwedy]

Vibration points problem at front. What is a UCA ?

 

[txgringo]

Steering stabilizer, loose wheel bearings, loose nut behind the wheel, loose caliper,...

I checked the front caliper bolts. They're at 83 ft lbs. I'll try to get it up and see if there's any slack on the wheel bearings indicating worn wheel bearings. Or did you mean the actual bearing/hub assembly might be loose (e.g. the 4 bolts holding the hub on the axle)?

Vibration points problem at front. What is a UCA ?

UCA = Upper Control Arm

 

[UTFJ]

I have the same problem. Following this tread so I can hopefully get this issue fixed. Drives me crazy sometimes!

 

[GXMac]

I had something like this happen to me but with slotted/ drilled rotors. It would only shudder under braking from 50 to 40 mph but not at higher or lower speeds. When I swapped out the rotors and pads for solid rotors and new pads the shudder went away. However, the old rotors and pads looked fine and I could not feel any warping- my guess is maybe something to do with the natural frequency of the rotor being hit at those speeds.

 

[GXO]

I had something like this happen to me but with slotted/ drilled rotors. It would only shudder under braking from 50 to 40 mph but not at higher or lower speeds. When I swapped out the rotors and pads for solid rotors and new pads the shudder went away. However, the old rotors and pads looked fine and I could not feel any warping- my guess is maybe something to do with the natural frequency of the rotor being hit at those speeds.

If you rule out the bearing (VERY likely) it can also be slop in the ball joints in the tie rods, lower or upper control arms, etc that allow brakes to make the wheel shake. Not feeling it at lower speed may be a misdirect. If you have tie rod slop you would feel wandering or other symptoms as well. Wheel bearing can do this for sure, as can rotors/pads. Mixed brands on brakes can cause it too due to different interactions with brake pad compounds and rotor surfaces. Need more diags.

 

[fastlane1000]

I have an 08 GX470 and I'm experiencing intermittent vibration/shudder when braking at highway speeds. It never happens when just driving (only when brakes are applied), and it never happens at lower speeds (e.g. under 50).

Since it is only happening while braking, conventional wisdom would point to an issue with rotors (warped or uneven wear from L to R) or possibly a sticky caliper grabbing harder on one side than the other. However, since it is not happening 100% of the time, I don't think the rotors would be the issue and since it doesn't happen at lower speeds I think a sticky caliper is unlikely.

Anyone have advice on what to check for this? Thanks in advance.

Others, I'm sure, are more experience with this platform but I had this exact issue on a previous vehicle. It was a 2005 Chrysler 300C SRT8. After replacing brake rotors the vibration was still there when braking. After some research I found a lower suspension link arm bushings could be to blame. I swapped it out and the problem was fixed. The equivalent on the GX would be lower control arms / bushings. If I were you I would have someone in the driver's seat moving the steering wheel back and forth while someone else lays down under the front of the vehicle. You want to look/feel for play in ball joints, bushings, etc. You can also jack the vehicle off the ground and try to move the wheel. With your hands at the 12 and 6 position the play is normally found in the wheel bearing or an upper or lower ball joint. With your hands at the 9 and 3 position you would find play in the tie rod.

No offense, but judging by your familiarity with the names of some of front end components you may want to ask a friend with more experience to work with you through the diagnoses. Hope this helps.

 

[CO_Hunter]

Are you feeling any pulsing in the brake pedal?

Also, this is a good read.

-Warped- Brake Disc and Other Myths

 

[joabmc]

Are you running OEM or aftermarket? I may have missed that. If so, have you recently swapped pads, rotors or both? Toyota runout specs are pretty fine IIRC. You could gage the rotors and be able to tell pretty quickly if that is the issue. I’ll look for the specs. as I used to have them. Also, the calipers on these rigs are known to seize. May want to inspect those as well.
That being said, I’ve never had much luck with aftermarket pads and rotors.

 

[txgringo]

Are you feeling any pulsing in the brake pedal?

Also, this is a good read.

-Warped- Brake Disc and Other Myths

Yes, I am getting pulsing in the brake pedal as well. I'll check out that link, thx.

Are you running OEM or aftermarket? I may have missed that. If so, have you recently swapped pads, rotors or both? Toyota runout specs are pretty fine IIRC. You could gage the rotors and be able to tell pretty quickly if that is the issue. I’ll look for the specs. as I used to have them. Also, the calipers on these rigs are known to seize. May want to inspect those as well.
That being said, I’ve never had much luck with aftermarket pads and rotors.

I'm not sure what rotors are on it; they were replaced before I bought it.

I have a set of DBA rotors that I was considering installing if things start to point at the rotors.

Regarding calipers seizing, wouldn't that happen at lower speeds as well? I could see that being the cause of an intermittent issue, but I would expect to see it happen at speeds under 50 as well as over.

 

[Arailt]

Both of my front calipers were seized when I bought my GX. Braking felt erratic and would pull to one direction very hard. It was actually more noticeable at low speeds, especially when coming to a stop to turn off the road. It did not cause any vibrations.