Hi Folks,
Took the LR3 out for backroad drive today. Soon after I shifted the terrain response system into Mud/Ruts, I used the brakes, and then heard a sound like something had dropped from the undercarriage and was dragging along the road. I also felt lots of road-like vibrations through the brake pedal - not the normal feeling associated with ABS, but a more varied feeling that matched the coarse grinding sound. It went away when I turned off the terrain response system, and returned if I tried it again. Any ideas? I'm pretty sure that the sway bar bushings or upper control arm bushings need to be replaced, as there's been a clunking sound on bumpy roads (and the lower control arm bushings were recently replaced). However, this is the first time I've heard this new sound, and it was odd that it seemed to be something that only happened with the combination of braking and using the terrain response system.
Many thanks,
Captain Sygo

 

Reading around a bit more, I'm starting to think that this might have just been the normal sound/feel of the hill descent control system...I'd never have thought that a vehicle would be designed to intentionally produce a sound like that! The two situations when I noticed it were going down a steep hill, and going really slowly on a flat.

Captain Sygo
'05 LR3 SE

 

Sounds like the terrain response and hill decent control doing its thing.

 

Thanks for confirming. The only other time I've heard a sound like that was back in the 80's when I was on backroads deep in the mountains in my '79 Subaru GL wagon and the exhaust line broke so that a 6 foot segment of it, anchored only at the rear end of the car, was dragging along the ground. I had only a short piece of rope to fix the problem (didn't want a dirty exhaust pipe bouncing around in the cabin with all of my stuff). So I ended up tying one end of the rope to the B pillar, then wrapped the other end around the broken end of the dangling exhaust pipe, then wedged a spoon up into the frame and tied the loose end of the rope to that. Managed to drive out on about 20 miles of forest roads and then 120 miles or so to home without a hitch.
-Captain Sygo

 

Captain, was the sound distinctly audible when you took your foot OFF the brake pedal? When you engage the foot brake, HDC disengages, and vice-versa.

 

Pretty sure it made the sound while I was stepping on the brake, as I definitely felt the grinding vibrations through the brake pedal. My recollection is that the sound stopped when I released the brake, and would return when I re-applied the brakes.
-Captain Sygo

 

On brake is more likely the abs going active

 

Concur with ArmyRover. You an always just go drive it around with the HDC on in your neighborhood and experiment.

 

Thanks to ArmyRover and houm_wa for the help. Finally had a chance to test the HDC under controlled conditions, and the sounds/behaviors from the rig matched exactly with what I'd experienced when off-roading. Going forward, I'll know to welcome that sound as evidence that the LR3 is doing its thing!

-Captain Sygo

'05 LR3 SE

 

Glad to help