Metal knocking sound from suspension
06-16-18, 06:22 AM
#1
Driver
Thread Starter
Metal knocking sound from suspension
I have a 2009 LS with AWD. There is a metal to metal sounding rapid knocking/rattle when I drive over bumpy roads (especially stutter bumps) or under light braking at 30 to 40 mph. The rattle is solid souding, not like sheet metal, more like suspension. I can’t feel it in the brake pedal or in the steering wheel. Car is steady as ever. It has 92k miles on it. Ball joints? Suspension bushings? Other ideas? Thanks in advance.
06-16-18, 02:36 PM
#2
Could be a multitude of things but from what your describing seems like maybe you need a new brake shim kit. My front pads do a similar thing, when i press the brake while driving over bumps the noise stops. Worst case scenario is you have an air strut making noise. Try to see if you can drive over small bumps and brake slightly at the same time to see if that eliminates or alleviates the noise. Bushings and ball joints could be a possibility. Oe ball joints are stout for the most part but bushings have had there ups and downs. Good luck ...please let us know what you find
06-17-18, 04:49 PM
#5
I had a really annoying rattle / clunk after I had a shop change out my shocks, until today. I took an experienced mechanic on a drive on Friday with me and from driving it for 5 minutes he diagnosed it as a sway bar issue. He suggested I buy new end links and sway bar bushings, front and rear, which he would install. I had already replaced the driver side front end link a few weeks ago (Beck Arnley) without solving the problem. I ended up ordering two new OEM sway bar bushing online yesterday but they haven't arrived yet. Today, I finally had a chance to go in and check the torque on everything. The sway bar bushing bracket bolts were fairly loose on each side so I snugged them up. I jacked up one side at a time which put torsion on the sway bar, which I've heard may be important. The end link to steering knuckle nut on one side was very loose and I snugged them down on both sides. The end link to sway bar nut was tight on both sides. After doing this, the clunk is gone! So I would make sure all those bolts are very tight or else you will get some serious clunking. At almost 220,000 miles my ride now finally feels tight and quiet after replacing all 4 shocks (KYB Gas-a-just) and changing a front wheel hub(Timken).
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diamente (06-21-18)
06-25-18, 06:47 PM
#6
Driver
Thread Starter
My car is at the dealer. The tech thinks that the noise is coming from the brake rotors being warped. My brakes have some minor pulsing but not much. And what it does have, I believe, is inherent to the brake actuator. The rotors are below minimum thickness so he wants to put new rotors on. He’s saying that he thinks the brake shutter is causing the suspension to rattle at light braking. He says that The suspension doesn’t feel loose, but thinks there’s enough play in the suspension that the brake rotors are causing the knock. I’m not sure I’m buying that. It’s a metal on metal knock. My brake pads aren’t very worn so it’s not like I need a brake job regardless. Thoughts?
06-25-18, 11:35 PM
#7
I haven't done a brake job on this vehicle but see if you can take off the wheel and see how loose the brake pads are. See if the brake cover or any metal plate is scratching the rotor. On mine, I only get metal knocking sound when driving a little hard over bumps and dips. I am thinking my sway bar bushings are worn out (they look fine) and causing the sway bar to hit the suspension reinforcement member. Let us know what your dealer find out.
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06-26-18, 02:27 AM
#8
Pole Position
My car is at the dealer. The tech thinks that the noise is coming from the brake rotors being warped. My brakes have some minor pulsing but not much. And what it does have, I believe, is inherent to the brake actuator. The rotors are below minimum thickness so he wants to put new rotors on. He’s saying that he thinks the brake shutter is causing the suspension to rattle at light braking. He says that The suspension doesn’t feel loose, but thinks there’s enough play in the suspension that the brake rotors are causing the knock. I’m not sure I’m buying that. It’s a metal on metal knock. My brake pads aren’t very worn so it’s not like I need a brake job regardless. Thoughts?
Honestly it was a great car though. Part of me wishes I kept it and just fixed it.
06-26-18, 05:55 AM
#9
Instructor
Well I'll tell you what, I've spent many many hours trying to figure out noises in the front of my LS460 and it's just so damn hard. The last thing it was doing before I traded it in was make a rubber rubbing noise when stopping and a clicking noise while turning (and the car was rear wheel drive). Replaced some control arms that felt loose at the ball socket. Replaced sway bar links and bushings. And I took apart the brakes and regreased everything. Did NOTHING to prevent my noises. The brake noise was my real concern because it seemed to grow worse by the day - eventually narrowed it down to the brake actuator - I could duplicate the noise by just applying the brake pedal (rubber rubbing sound/squeak). It would even do it with the car off, and the sound was coming right from the actuator. As for the clicking sound when turning? Never go to to that. Figured why bother when the brake actuator is junk?? But I couldn't think of anything. The wheel bearings seemed fine. The ball joints were tight. The control arms were new. I mean there was nothing left except the struts, so I traded it in...wasn't about to replace the struts and pump/actuator.
Honestly it was a great car though. Part of me wishes I kept it and just fixed it.
06-26-18, 06:52 AM
#10
Doublebase, There are lots of very nice LS460s out there -- sounds to me like you really want to get another one! I had the same feeling after I traded my 2008 LS600hL in on a 2017 Genesis G90... The Genesis was a very nice car, but I just missed my old LS... You should find a nice deal on a LS460 and rejoin us!
06-26-18, 07:59 AM
#11
Well I'll tell you what, I've spent many many hours trying to figure out noises in the front of my LS460 and it's just so damn hard. The last thing it was doing before I traded it in was make a rubber rubbing noise when stopping and a clicking noise while turning (and the car was rear wheel drive). Replaced some control arms that felt loose at the ball socket. Replaced sway bar links and bushings. And I took apart the brakes and regreased everything. Did NOTHING to prevent my noises. The brake noise was my real concern because it seemed to grow worse by the day - eventually narrowed it down to the brake actuator - I could duplicate the noise by just applying the brake pedal (rubber rubbing sound/squeak). It would even do it with the car off, and the sound was coming right from the actuator. As for the clicking sound when turning? Never go to to that. Figured why bother when the brake actuator is junk?? But I couldn't think of anything. The wheel bearings seemed fine. The ball joints were tight. The control arms were new. I mean there was nothing left except the struts, so I traded it in...wasn't about to replace the struts and pump/actuator.
Honestly it was a great car though. Part of me wishes I kept it and just fixed it.
That sounds like the brake actuator which there many threads on this issue. If mine were to went out, I would get an used part off of ebay or junkyard to swap it out.
I am very curious on repairing brake actuator. Has anyone ever think of repairing it? If I could get hold of the wiring diagram, and instructions, it would be a fun project.
06-26-18, 10:42 AM
#12
As I have previously stated a loose front bumper will rattle and sound just like a suspension noise. Happened to me and I secured my bumper from below at all points to my very front cross member by the radiator with sheet metal screws. My front end is all new so I narrowed down the noise by bumping the bumper with my palm in all places and recreating the suspension like sounds. I also removed the noisy splash shield that really doesn't cover much that isn't already covered by other things. Of course every situation is different. Noises and intermittent problems are the mechanics worst jobs.
06-26-18, 02:41 PM
#13
Pole Position
That sounds like the brake actuator which there many threads on this issue. If mine were to went out, I would get an used part off of ebay or junkyard to swap it out.
I am very curious on repairing brake actuator. Has anyone ever think of repairing it? If I could get hold of the wiring diagram, and instructions, it would be a fun project.
I am very curious on repairing brake actuator. Has anyone ever think of repairing it? If I could get hold of the wiring diagram, and instructions, it would be a fun project.
I too wonder if anyone has repaired one of these things, I imagine so. With so many failed units out there, you know someone is rebuilding them. I don't think you'd need a wiring diagram for the actuator, you'd need seals, and some patience. There is a company down south (forget where they are) that rebuilds brake actuators for $300-$400, but you have to ship it and be without your car for who knows how long.
06-26-18, 02:45 PM
#14
Pole Position
Doublebase, There are lots of very nice LS460s out there -- sounds to me like you really want to get another one! I had the same feeling after I traded my 2008 LS600hL in on a 2017 Genesis G90... The Genesis was a very nice car, but I just missed my old LS... You should find a nice deal on a LS460 and rejoin us!
06-26-18, 04:38 PM
#15
I considered buying a an actuator off eBay for $700-$800 bucks but a couple things made me change my mind...buying a used unit with who knows how many miles (when they're prone to failure) didn't entice me too much. And the demand for these thugs has driven the prices on the used market up a bit compared to prices from a few years ago. I was seeing actuators on there for $1,200 and up.
I too wonder if anyone has repaired one of these things, I imagine so. With so many failed units out there, you know someone is rebuilding them. I don't think you'd need a wiring diagram for the actuator, you'd need seals, and some patience. There is a company down south (forget where they are) that rebuilds brake actuators for $300-$400, but you have to ship it and be without your car for who knows how long.
brake actuator Toyota Landcruizer fixed by an electrician.
he said, despite huge price from Toyota ($1,400), its truly just a 12V motor. Nothing exotic or special.
Refinishing the commutator, new bushes, new bearings and its good to go for another 100K.
brake actuator on LX450 fixed. same link as above. scroll down.
"I removed the booster as you guys said and I brought the 12v motor to a car starter specialist and all he did was replace the brush and the commutator. To keep from charging me a premium price, I told him that the motor is for an old toyota forklift, as a result I was only charged $55!"
on the same thread:
"I had similar symptoms but fortunately an easy fix. The "ABS" and "Brake" lights came on and the buzzer sounded within a few seconds of turning the key to the "on" position. I heard the ABS motor relays in the relay box behind the battery clicking but did not hear the booster pump motor operating, so I connected an insulation-piercing test clip to the red heavy-gauge wire from the ABS module to the booster pump motor under the master cylinder. I connected the other test lead to ground to measure the voltage of the red wire when the ABS motor relays were closed. Not only did I see 13 volts on the red wire when the relays were closed (and 0 volts when the relays were open), but I also heard the booster pump motor running for the first time since the failure occurred. It took a while for the booster pump motor to pump up the accumulator, but eventually the "ABS" and "Brake" lights went dark and the buzzer stopped. Apparently just tugging on the red wire to connect the test clip was enough to fix whatever loose connection it had.
I pulled the rubber boot off the screw terminals for the two booster pump motor wires (the red one and a blue one) on the bottom of the ABS module. I disconnected the negative battery terminal from the battery and used a ratcheting Phillips offset screwdriver to tighten the two Phillips screws connecting lugs on the two wires to the ABS module. With only very moderate torque, I was able to tighten the screw for the red wire about 10 degrees of rotation. The brakes worked perfectly during a test drive.
Before you remove the entire ABS module/booster pump/accumulator/master cylinder assembly and introduce air into the brake hydraulic systems, it takes only a multimeter to measure the red wire voltage, a 10mm wrench to remove the battery terminal, and a Phillips offset screwdriver to retorque the screw terminals on the bottom of the ABS module to see, within a few minutes, if you have the same simple problem I had. You might want to read any OBDII codes before you disconnect the battery and erase any codes, although no codes were ever set over the course of my problem. Rather than using an insulation-piercing test clip, it may be better to just touch two test probes across the two screw terminals and measure the actual voltage across the red and blue wires going to the booster pump motor that way. Just be careful not short the red wire to the blue wire or any other ground point or voltage.
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Doublebase (06-26-18)