(Another) Front suspension noise/steering rack question (1 Viewer)

[4gotalot]

I found some speed bumps in the hospital parking lot less than a mile away so went over them at different "parking lot" approved speeds many times and different out side temps to find the fault "clunk" with the ARB shock mount bushings. I then had my son stand off to the side of the speed bump as I went over and listen to the clunk and he could hear front or rear axle. Some times the clunk was delayed a couple of feet/seconds after the speed bump so having a witness outside narrowed it down quickly in that situation.

Can you find a location that the noise can be repeated ie turning into drive way, speed bump. Have a friend that trusts your driving skills stand by and they may be able to recognize front of tire, aft of tire, behind tire or mid section under body.

 

[bloc]

Chassis ears? I'll loan you my set if you don't want to invest.

 

[linuxgod]

KDSS arm bolts tight and bushings in good shape?

It definitely looks tight. I can break out the torque wrench to confirm.

My bushings have 150k of wear. The remaining ones I haven’t replaced all seem like they’re in decent shape to me, with the exception of the passengers rear sway bar frame mount which are tight but definitely shot. That’s passenger rear though and the last time I heard this and was outside the truck the noise definitely sounded like it was up front somewhere. That said, thanks for the reminder that I need to replace that one

 

[linuxgod]

Chassis ears? I'll loan you my set if you don't want to invest.

I do have a set. I should’ve bought the wireless ones, the hassle to run wires out of the way of anything moving keeps me from pulling them out and using them sometimes. Originally I thought this was a suspension issue so I’d tried some go pro mounting first since it’s hard to attach them to round and moving components but saw nothing odd. It’s also a bit annoying that it’s not repeatable… sometimes it makes noise and sometimes not, so unless it’s happening repeatedly I might have to wait a day or two before it starts happening again

 

[linuxgod]

I found some speed bumps in the hospital parking lot less than a mile away so went over them at different "parking lot" approved speeds many times and different out side temps to find the fault "clunk" with the ARB shock mount bushings. I then had my son stand off to the side of the speed bump as I went over and listen to the clunk and he could hear front or rear axle. Some times the clunk was delayed a couple of feet/seconds after the speed bump so having a witness outside narrowed it down quickly in that situation.

Can you find a location that the noise can be repeated ie turning into drive way, speed bump. Have a friend that trusts your driving skills stand by and they may be able to recognize front of tire, aft of tire, behind tire or mid section under body.

My garage is about the closest “guaranteed” spot, and that’s probably once or twice a week where I hear this. It’s kind of like something shifts and then it’s quiet for a while, but then something shifts again and it’ll pop for a few turns or a few drives before it’s quiet again.

 

[TheGrrrrr]

I get something similar under similar conditions. Definitely metallic and sounds less like contact and more like something under tension slipping out of contact with whatever was creating the tension. Like a spring coming out of its seat kind of sound is the best my brain can come up with. It’s happened pretty consistently the entire time I’ve owned it. I’m on OME nitros.

 

[linuxgod]

I get something similar under similar conditions. Definitely metallic and sounds less like contact and more like something under tension slipping out of contact with whatever was creating the tension. Like a spring coming out of its seat kind of sound is the best my brain can come up with. It’s happened pretty consistently the entire time I’ve owned it. I’m on OME nitros.

Yeah, this. Mine hasn’t done it the whole time… definitely started maybe 20-30k ago, that description about slipping is spot on

 

[4gotalot]

I get something similar under similar conditions. Definitely metallic and sounds less like contact and more like something under tension slipping out of contact with whatever was creating the tension. Like a spring coming out of its seat kind of sound is the best my brain can come up with. It’s happened pretty consistently the entire time I’ve owned it. I’m on OME nitros.

The bushing material and stack of washers for the top mount of the ARB/BP51 and ARB/OME Nitros front and rear is the common denominator for the clunk/metalic clink as the shaft and pilot washer would slide back into the hole in the frame. Thats were the timing was off from going over the speed bump to when the assembly slid back into its place. When the outside temperature in the spring time in MT hit around 40 f the noise would come back. I am guessing the rubber bushing material would soften enough to reduce the compression load on the stack.

 

[isthatalexus]

Grasping at straws here, and understading that you hear the noise at the bow, not the stern: are the rear coils seated properly? Is the valley in which those coils are seated on the axle clean and free of dirt and little rocks?

When I recently dropped in 2723's, I brushed a bunch of crud out of the circle valley. Also, the 'stop' point at which the spring is seated correctly is not so much of a 'point' as it is a general area; it's a kind of swoop upward, and it feels like the spring could be seated in a range of possibly 'correct' positions. There's not a hard vertical stop point. Maybe a slight mis-seating at the rear spring on one side is causing it to come up during flex, and reseating with a clack on compression.

 

[TheGrrrrr]

Grasping at straws here, and understading that you hear the noise at the bow, not the stern: are the rear coils seated properly? Is the valley in which those coils are seated on the axle clean and free of dirt and little rocks?

When I recently dropped in 2723's, I brushed a bunch of crud out of the circle valley. Also, the 'stop' point at which the spring is seated correctly is not so much of a 'point' as it is a general area; it's a kind of swoop upward, and it feels like the spring could be seated in a range of possibly 'correct' positions. There's not a hard vertical stop point. Maybe a slight mis-seating at the rear spring on one side is causing it to come up during flex, and reseating with a clack on compression.

My working theory has always been that its related to the KDSS somehow. I bought my truck at 89k miles and almost immediately put the OME Nitros on it, so can't speak to the stock suspension... but I really think its KDSS related, mike maybe it goes from working hard to disengaging abruptly because some threshold gets hit that causes it for a singular moment to think its off-road?

 

[linuxgod]

My working theory has always been that it’s related to the KDSS somehow. I bought my truck at 89k miles and almost immediately put the OME Nitros on it, so can't speak to the stock suspension... but I really think its KDSS related, mike maybe it goes from working hard to disengaging abruptly because some threshold gets hit that causes it for a singular moment to think its off-road?

That should be easy to test, just open the valves 2 turns and drive it. If the noise keeps happening then it’s something else, but if it stops then winner winner chicken dinner. Mine didn’t used to make this noise though.

 

[linuxgod]

Grasping at straws here, and understading that you hear the noise at the bow, not the stern: are the rear coils seated properly? Is the valley in which those coils are seated on the axle clean and free of dirt and little rocks?

When I recently dropped in 2723's, I brushed a bunch of crud out of the circle valley. Also, the 'stop' point at which the spring is seated correctly is not so much of a 'point' as it is a general area; it's a kind of swoop upward, and it feels like the spring could be seated in a range of possibly 'correct' positions. There's not a hard vertical stop point. Maybe a slight mis-seating at the rear spring on one side is causing it to come up during flex, and reseating with a clack on compression.

My rears are good but maybe I’ll hit the top of the front coils with some silicone spray just for kicks

 

[4gotalot]

My rears are good but maybe I’ll hit the top of the front coils with some silicone spray just for kicks

Use an inspection mirror and a light to look at the top of the washer/bushing stack of the front strut. You are looking for dust, dirt and road gunk evenly applied by natural causes. You should not see any displaced dirt on the painted surface, shiny metal or black carbon like dust around the bushings and washers.

 

[linuxgod]

Use an inspection mirror and a light to look at the top of the washer/bushing stack of the front strut. You are looking for dust, dirt and road gunk evenly applied by natural causes. You should not see any displaced dirt on the painted surface, shiny metal or black carbon like dust around the bushings and washers.

If these have shifted, can you simply tighten the top nuts or do the coil overs need to come out and have the washers replaced?

 

[4gotalot]

If these have shifted, can you simply tighten the top nuts or do the coil overs need to come out and have the washers replaced?

Do not lift the tire off the ground at all ! Just throw an old towel over the tire its easy to see the top of the strut with a mirror and light.

The easy fix for trouble shooting purposes is just add another 1/8" shock washer with the same diameter hole on top of the the stack. This will increase the pressure on the existing rubber bushings holding them in place. Just make sure both washers clears the shoulder of the threaded portion and the nut bottoms out to take the proper torque.

The extra shock washer can be removed if the noise is still there and all looks good in that area. The nut may need to be replaced if its rusted to the threads. EP grease on the threads is a good way to reduce galling.

 

[linuxgod]

Do not lift the tire off the ground at all ! Just throw an old towel over the tire its easy to see the top of the strut with a mirror and light.

The easy fix for trouble shooting purposes is just add another 1/8" shock washer with the same diameter hole on top of the the stack. This will increase the pressure on the existing rubber bushings holding them in place. Just make sure both washers clears the shoulder of the threaded portion and the nut bottoms out to take the proper torque.

The extra shock washer can be removed if the noise is still there and all looks good in that area. The nut may need to be replaced if it’s rusted to the threads. EP grease on the threads is a good way to reduce galling.

When you say add to the top stack, do you mean where the yellow arrow is, or do you mean drop the coil over and add one to the red arrow (underneath)? Im assuming yellow, just confirming because I didn’t do the install myself

 

[4gotalot]

Disregard. Thats a good photo. I don't see any indication of movement from those mounts. The cross pin that is out of sight would leave some streaks down the side if it were not secure.

 

[linuxgod]

I think my next likely unnecessary expense will be to swap the top front body mount bushings. If you look back at my post #32 that top mount looks collapsed to me. Granted I can’t actually see what the other mounts look like but even left vs right side you can see a difference in spacing between the rings (basically none on the drivers side). These are fairly cheap I just need to figure out how to jack the body up safely so I can remove them

(Another) Front suspension noise/steering rack question

I would ck with Slee for replacement parts (I'm sure they have lots) and their experience with the bushings. When the faulty bushings are installed, they look and feel just like any other we have installed for many years but after getting compressed and rebound the bushings act more like old...

forum.ih8mud.com

 

[isthatalexus]

My working theory has always been that its related to the KDSS somehow. I bought my truck at 89k miles and almost immediately put the OME Nitros on it, so can't speak to the stock suspension... but I really think its KDSS related, mike maybe it goes from working hard to disengaging abruptly because some threshold gets hit that causes it for a singular moment to think its off-road?

I always thought that KDSS would change the level of actuation based on speed...at least that is what I recall from my GX470 days when I first dove into the details of the system. Could be different for the LC, or I'm just hallucinating like a neural network with forgotten probabilities in those token locations.

 

[linuxgod]

I always thought that KDSS would change the level of actuation based on speed...at least that is what I recall from my GX470 days when I first dove into the details of the system. Could be different for the LC, or I'm just hallucinating like a neural network with forgotten probabilities in those token locations.

I think the LC version is based on amount of speed of pressure change. That largely maps to vehicle speed, but the LC version is fluid-mechanical, nothing electronic making the decisions. At low speed fluid can move between chambers but at high speed it can't move fast enough.