Random onset of shudder/shake

[M5Z3M]

My 2012 V8 LR4 (78,000 miles) is suffering from the random onset of what quickly becomes severe shaking/shuddering. Sometimes it starts shortly after moving off from a standstill; other times I can drive 500+ miles uneventfully.
The shudder starts as if I'm driving over a mildly washboarded surface but soon progresses to an alarming frequency. Bringing the vehicle to a halt on the shoulder and then moving off again usually fixes it; backing up and braking quite hard seems to be a more surefire way of eliminating the phenomenon until it happens again.
During the process of stopping the vehicle's forward motion, I can feel some rotational friction points, suggesting some sort of brake hangup. An IR thermometer has not shown any hot rotors, but the next time it happens I plan to endure the shaking for longer so there's more time for any temperature rise to show itself.
It has been a salt-belt car from new in Buffalo. Caliper corrosion? Wheel bearings?
Thanks for any other theories anyone might have or, better yet, experience with the problem and a fix for it.
M5Z3M

 

[ryanjl]

Search for rear lower control arm bushings. My guess is that it's those.

Have you seen any mystery fluid on your garage floor to the inside and rear of either of your front tires?

Wheel bearings are easy to check. Jack up a corner of your car and put your hands at the 9 and 3 positions on the wheel. See if there's any wiggle. Repeat at the 12 and 6.

If it does not require you to be braking to shudder, your brakes are unlikely to be the culprit.

 

[M5Z3M]

No, I haven't seen any mystery fluid anywhere on the garage floor.
My mechanic (up to speed on LR3s and 4s) says he looked closely on the lift and couldn't see anything amiss.
New blacktop put down here as recently as last year is already corrugated and a pain in the **** for the LR4 suspension (even more so for my M5's), but there's no consistency or predictability in what triggers the LR4's shakes.
I'll have my mechanic look at the control arm bushings.
Thanks for the tip, ryanjl
M5Z3M

 

[ryanjl]

The control arm bushings are a common issue on vehicles of your mileage. Mine went this past December with similar (if not as severe) symptoms as you. The bushings are fluid-filled, so when they really go they puke their guts on the floor. Mine showed the shudder symptoms for a little while before they puked, though.

The best cure is to just replace the whole lower control arm, which gets you a new front bushing and a new ball joint as a byproduct. Parts cost a little more, but you save in the labor of removing the old bushing, which can be a PITA.

 

[M5Z3M]

Thanks. I will install new ones and report back

 

[PaulLR3]

Funny, I was driving home to Boston from Buffalo last night and noticed an odd vibration that only occurred on stretches of new blacktop at high speeds. Mine feels like I have a damaged belt inside one of the tires, which is possible given the number of potholes I hit in spring.

But your issues sounds like a brake caliper starting to hang up. I've had 2 rear calipers go bad and sometimes it starts as a gradual thing that comes and goes.

 

[M5Z3M]

The tires were my prime suspect initially because the problem first arose a few hundred miles after a tire shop had lost track of which wheel was where during a simple tire rotation. Some of the tires rotated in the opposite direction after the botched work, but a different shop thought it's unlikely a tire mixup is causing the shudder. Also, wouldn't the problem be continuous if it was caused by tires?
The speed with which new blacktop is laid around here makes me wonder if new technology in that business is a step backwards in longevity. Much of the blacktop put down around here (upstate NY) these days develops across-the-roadway corrugations between summer and spring.
Thanks for responding, PaulLR3

 

[M5Z3M]

My mechanic insists bushings on rear lower control arms are sound, so I have two new arms with bushings on a shelf in barn. Open to offers (they’re heavy items to ship) or I’ll just keep them for future use.
I think the right rear brake may be the cause. That rotor is running 20 to 30 degrees hotter than the others and squeaks with a rotational rhythm occasionally. Will look into a new caliper.

When the shudders set in now I keep driving and they disappear quite quickly.

M5Z3M

 

[Travis]

I experience the occasional shuddering as well. Sometimes I slow down and it goes away and I think to myself "well it must just be the road".

I had an issue with my right rear brake rotor recently basically grinding right to the metal on the outside. The brake sensor never came on, and it just seemed like the outside pad was worn through. I then replaced th rear pads and rotors on both sides, and it felt like the drivers side brake was still "dragging" more. I had a coupon for a free brake inspection at the Land Rover dealership, and they looked it over and they said everything looked good. They did say to make sure the caliper pins were lubricated well. So I took the caliper pins out (they looked good), cleaned them, and lubricated with high temp brake grease. Also lubricated the slides.

I'll report back if the problem keeps occurring. Right now I have the vehicle on the battery charger trying to figure out a different issue (that I just posted about in a different thread).

 

[M5Z3M]

Travis:
All this is good to know. Thanks.
M5Z3M