Help diagnose my front end shake on braking.

[woodman60]

I've looked at numerous past threads on this issue, but there's very little that's definitive from people who have actually fixed the problem themselves. A lot of opinions on what causes it.

Any help before I invest serious dollars.

The problem: When braking at highway speed, shimmy from front end which shakes the steering wheel back and forth. Most noticeable when going downhill (50 – 70 mph or so) and applying light to moderate braking to reduce speed. Does not pull to either side. Steering wheel shales fairly violently (enough that its a little scary), but the vehicle doesn't really shake.

Notably, a very similar steering wheel shake at low speed (5 mph or less) on dirt with minor bumps/washboards. Wheel shakes more than would be expected form the road conditions.

Tires recently roteted and balanced. Vehicle tracks straight on pavement. No vibration at any speed when not braking. Vehicle has 250K miles, Dobinson's suspension and new LCAs installed a couple of years ago. Front brakes done and left caliper replaced about 30K ago.

Brakes? Suspension? Steering? Where to start? I recognize that this may become a series of fixes.

 

[shiftmx]

If you haven't replaced your rotors when you did the front brakes, start there. I would stick with OEM or brembo blanks.

 

[Buckaroo]

I've looked at numerous past threads on this issue, but there's very little that's definitive from people who have actually fixed the problem themselves. A lot of opinions on what causes it.

Any help before I invest serious dollars.

The problem: When braking at highway speed, shimmy from front end which shakes the steering wheel back and forth. Most noticeable when going downhill (50 – 70 mph or so) and applying light to moderate braking to reduce speed. Does not pull to either side. Steering wheel shales fairly violently (enough that its a little scary), but the vehicle doesn't really shake.

Notably, a very similar steering wheel shake at low speed (5 mph or less) on dirt with minor bumps/washboards. Wheel shakes more than would be expected form the road conditions.

Tires recently roteted and balanced. Vehicle tracks straight on pavement. No vibration at any speed when not braking. Vehicle has 250K miles, Dobinson's suspension and new LCAs installed a couple of years ago. Front brakes done and left caliper replaced about 30K ago.

Brakes? Suspension? Steering? Where to start? I recognize that this may become a series of fixes.

There is an interesting app called Smoothride Pro by Pro-Cut that might give you some information. It helps distinguish between rotor thickiness variation (i.e. warped rotors) and wheel balance issues. Have used it and found it to be pretty accurate. Good to use it to get a baseline before you have issues but suggest you give it a go. Kind of sounds like rotor related issue. If you replace them, clean the hub well and verify rotor run-out in spec with a dial indicator.

Smoothride PRO | Pro-Cut On Car Brake Lathes

 

[woodman60]

Worn parts. Replace anything worn.

Anything in particular? At 20 years and a quarter million miles there’s a lot of worn parts…

 

[Lineman]

Have you checked for frozen calipers? These 4th Gens eat stock or auto zone type. I went with Powerstops my last round and haven’t looked back.

Also, could be a hub going bad.. Around 200K the average on them. If you do one, do both.. But these normally make noise when going bad.

 

[OopsIBrokeIt]

Have you checked for frozen calipers? These 4th Gens eat stock or auto zone type. I went with Powerstops my last round and haven’t looked back.

Also, could be a hub going bad.. Around 200K the average on them. If you do one, do both.. But these normally make noise when going bad.

I had a mild wiggle on braking, with zero noticeable play when I jacked it up and shook the wheel/tire. I'd also replaced all bushings + ball joints + the shock + pads/rotors/calipers in the last 5k or so to help improve the ride and that brake issue persisted.


Finally replaced both front hubs and ta-daa, the issue was gone immediately and the bearings were definitely crusty and slightly corroded when I got them out to look. Given the age/mileage mentioned here I'd be checking tie rods, and strongly considering either pulling a hub to check or just replacing them for the hell of it.

 

[Hungryhawk]

Classic cause is rotor problems. Usually by switching brands of pads and not turning rotors to get old pad material off. You could have an pad material uneven buildup on your rotors -often called warped rotors.
Also bed-in your pads on refinished rotors to apply an even coating of pad material onto rotors.
My 2 cents.

 

[Berty_K]

Also had a similar issue at very similar conditions to yours (shimmy when braking at speed).

Turned out my upper control arm (JBAs) ball joints and bushings were worn. I could feel a bit of play through the steering knuckle.

Replaced both and things felt tight again.

 

[truckmike26]

My vote goes to a sticking front caliper piston/uneven inside/outside rotor wear. Also, torque the wheel nuts by hand with a torque wrench set to 83 ft.-lbs.

 

[CarlosV]

Same symptoms. Sticky calipers. Powerstops solve it

 

[Reinout]

I've looked at numerous past threads on this issue, but there's very little that's definitive from people who have actually fixed the problem themselves. A lot of opinions on what causes it.

Any help before I invest serious dollars.

The problem: When braking at highway speed, shimmy from front end which shakes the steering wheel back and forth. Most noticeable when going downhill (50 – 70 mph or so) and applying light to moderate braking to reduce speed. Does not pull to either side. Steering wheel shales fairly violently (enough that its a little scary), but the vehicle doesn't really shake.

Notably, a very similar steering wheel shake at low speed (5 mph or less) on dirt with minor bumps/washboards. Wheel shakes more than would be expected form the road conditions.

Tires recently roteted and balanced. Vehicle tracks straight on pavement. No vibration at any speed when not braking. Vehicle has 250K miles, Dobinson's suspension and new LCAs installed a couple of years ago. Front brakes done and left caliper replaced about 30K ago.

Brakes? Suspension? Steering? Where to start? I recognize that this may become a series of fixes.

This sounds like warped brake rotors: you can take them to an auto shop and have them measure the run-out and potentially face them.

Or you can buy new rotors.

 

[Usurper]

I had a similar issue, rotors are worn most likely and I would check for a seized caliper as well. Power stop makes a great replacement caliper.

 

[Gannz22]

I had a similar issue, rotors are worn most likely and I would check for a seized caliper as well. Power stop makes a great replacement caliper.

I had a powerstop caliper seize up after only 2 years. The red is real pretty but I learned my lesson... only OEM for me if available.

 

[truckmike26]

I had a powerstop caliper seize up after only 2 years. The red is real pretty but I learned my lesson... only OEM for me if available.

I put brand new OEM calipers from the dealer two years ago. A month ago, I opened the bleeder screws, pushed the pistons back in fully to purge the fluid in the calipers from the bleeder screws. Then I flushed the front lines while topping up the master cylinder. It's but one way to get more life from a set of calipers.

 

[Gannz22]

I put brand new OEM calipers from the dealer two years ago. A month ago, I opened the bleeder screws, pushed the pistons back in fully to purge the fluid in the calipers from the bleeder screws. Then I flushed the front lines while topping up the master cylinder. It's but one way to get more life from a set of calipers.

Good tip. Probably unwarranted but I just didn't trust them after they seized up.

 

[RESP1]

Shake n' Brake

Likely Culprits (in order of probability):
* Warped Brake Rotors: This is the most common cause of steering wheel shake when braking, especially at higher speeds.
* Why it fits: Downhill braking generates more heat, which can warp rotors over time. The shaking at low speeds on uneven surfaces might indicate uneven rotor wear or deposits.
* What to check: Visually inspect the rotors for any signs of warping (uneven surface, blueish discoloration). Measure rotor thickness and runout (wobble) with a dial indicator.
* Sticking Brake Caliper: A caliper that doesn't release fully can cause uneven braking and shaking.
* Why it fits: Might explain the low-speed shake if the caliper is dragging slightly.
* What to check: After driving, carefully feel the temperature of each wheel hub. A significantly hotter one suggests a sticking caliper.
* Suspension Components: While you've upgraded some parts, worn bushings or ball joints can introduce play and contribute to shaking.
* Why it fits: Loose components can amplify vibrations, especially on uneven surfaces.
* What to check: Have a mechanic inspect for any excessive movement in control arm bushings, ball joints, and tie rod ends.
* Wheel Bearings: A worn wheel bearing can cause vibration and shaking, sometimes more noticeable during braking.
* Why it fits: Less likely given no vibration at speed without braking, but still worth considering at 250K miles.
* What to check: Jack up the front end and check for play in the wheels by grabbing them at 12 and 6 o'clock and trying to rock them. Also, listen for any grinding or rumbling noise when spinning the wheels.
Less Likely (but still possible):
* Tires: While you've rotated and balanced them, there's a slight chance of a tire issue, especially given the low-speed shake. Check for uneven wear or any bulges/damage.
* Steering Rack: Problems here usually cause more consistent issues, but wear can contribute to shaking in some cases.
Where to Start:
* Thorough Brake Inspection: Start with the most likely cause – the brakes. Have the rotors inspected and measured. If they're warped or excessively worn, have them resurfaced or replaced (along with new pads).
* Caliper Check: While inspecting the brakes, check the calipers for proper movement and signs of sticking.
Important Notes:
* Don't automatically assume warped rotors! While common, it's crucial to rule out other issues.