AHC woes (1 Viewer)

[Das Shtig]

TL;DR: What are the signs and symptoms of AHC shock absorber failure?

FULL STORY: I’ve been trying to trace a front passenger side suspension noise on my ‘01 LX470 for months and a few weeks ago I decided to spend the diagnostic fee at Lexus to have them track it down (I’m injured and can’t wrench on it myself and none of my shade tree friends could figure it out). Blah blah blah, they tell me it’s the shocks and I say “are you sure they seem perfectly fine” and they insisted and I said ok put in the new shocks then. Aaaand it still making the noise. Now they want me to spend more diagnostic money for them to find the noise I just gave them $800 to fix. I’d like to argue with them but first I’d like to know what even happens to the shock absorbers when they go out. My AHC goes up and down fine, my shocks felt firmer in sport and softer in comfort yadda yadda. I told them I didn’t think it was the shocks but they assured me and $800 later I’m still in the same place I was with the noise. So arm me with some facts about symptoms of faulty AHC shocks so I can try to get them to fix my rig for no extra money. If you had shocks go out on your LX, what did they act/sound like? Thanks...

 

[uHu]

There are no normal shocks on an LX470 (or a 100 series with AHC). What looks like shocks are hydraulic rams -- They last until they start leaking too bad or rust to pieces, generally (if the Lex dealer doesn't know this, then sue them). Read more on the ahc in this forum. There's tons.
Noise could be a lot of things, depending on the type of noise... Suspension related you have (in order of likeliness): shock mount bushings (ok, rams), stabilizer bar bushings and links, upper and lower balls, upper and lower arm bushings, what else?

 

[Das Shtig]

There are no normal shocks on an LX470 (or a 100 series with AHC). What looks like shocks are hydraulic rams -- They last until they start leaking too bad or rust to pieces, generally (if the Lex dealer doesn't know this, then sue them).

So, to clarify, there’s no way they could break or wear in such a way that they make a clunking noise from the inside? This is what they claimed....

 

[klax18]

Correct, there is nothing in the shock that would wear and cause a noise.

 

[flintknapper]

So, to clarify, there’s no way they could break or wear in such a way that they make a clunking noise from the inside? This is what they claimed....

If you could expand on what the noise sounds like, intensity...etc, when it happens and under what conditions, we might be better able to diagnose your issue.

As previously stated...the 'shocks' are not unlike hydraulic rams and the most common 'failure' would manifest as a 'leak'. Structurally...if you live in the rust belt, it would be possible for them to literally rust through.

But as for 'internal' failures...it would pretty much have to be confined to a piston, rod or seal. Not very likely.

IF your Globe(s) are not working correctly (damping) then some amount of hydraulic shock could be transmitted to the body...which would sound like a loud clunk/thud. The same would be true if any of the assorted suspension bushings were worn (particularly the shock bushings).

We will assume your torsion bars are properly adjusted and that your front to rear hydraulic pressures are in spec.

Otherwise it's possible you are actually hitting the bump stop(s). Surely, they would have caught something like that?

Since replacement of the shocks did not solve your issue....I would be asking them why they were so adamant about replacing them and what diagnostic procedure they used to reach such a conclusion.

 

[NC-Grayson]

Wait.....so you spent $800 at the deslership and they didnt give you a definitive answer? AKA they lied to you about front shocks???? Remind me not to go to that stealership, ever. Your ahc should not be making any audible noise from the front end. Period. There are no front shocks as has been said before. My $0.02 is on a bushing, a brake dust shield, or another bushing.

What EXACTLY did you spend $800 on?

 

[flintknapper]

^^^^^ Unfortunately, many (if not most) dealerships are poorly versed concerning the AHC system.

Some have actually refused to do diagnostic testing or repairs short of replacing the entire system.

 

[Das Shtig]

If you could expand on what the noise sounds like, intensity...etc, when it happens and under what conditions, we might be better able to diagnose your issue.

As previously stated...the 'shocks' are not unlike hydraulic rams and the most common 'failure' would manifest as a 'leak'. Structurally...if you live in the rust belt, it would be possible for them to literally rust through.

But as for 'internal' failures...it would pretty much have to be confined to a piston, rod or seal. Not very likely.

IF your Globe(s) are not working correctly (damping) then some amount of hydraulic shock could be transmitted to the body...which would sound like a loud clunk/thud. The same would be true if any of the assorted suspension bushings were worn (particularly the shock bushings).

We will assume your torsion bars are properly adjusted and that your front to rear hydraulic pressures are in spec.

Otherwise it's possible you are actually hitting the bump stop(s). Surely, they would have caught something like that?

Since replacement of the shocks did not solve your issue....I would be asking them why they were so adamant about replacing them and what diagnostic procedure they used to reach such a conclusion.

They said they put wireless “ears” all over the suspension and it “seemed to be coming from the shock absorber itself”. Again, I said this seemed highly unlikely but if they were sure...

Avoid this stealership... Lexus of Orlando. They also once told me they lubricated my driveshaft when in fact they did nothing. And the service manager had the nerve to insult my car for having 215,000 miles, suggesting it was unreasonable to expect clunk-free driving.

No, admittedly my torsion bars are not properly adjusted. My ride height was out of whack and a friend helped me get it right by adjusting the torsion bars. I think the right one is fully cranked. My drivers side was low and this balanced it. I don’t have the pressure checking tool or is have done it by now. I read about the pressures needing to be within spec after I did it (and I’ve been injured for a couple months so I’ve been pretty limited). But surely they would’ve noticed the torsion bar position? It’s visisble, they’ve had my truck for daaaays. Anyway, this may be my bad here?

The car did come from the rust belt and was a bit rusty underneath, though I’ve had the rust treated since I bought it and brought it to Florida. They didn’t report the shock had rusted through. Could this have rusted internally and be consistent with their diagnosis (I’m trying to give them the benefit of the doubt)?

Here’s the facts:
2001 LX470
214,827miles, I’ve had it for two years and 3 months, and I’ve put 80k miles on it in that time. And about $10k in maintenance... here’s the relevant stuff:

-Front “shocks” replaced just days ago now (previously they had been done by PO around 120,000miles)
-CV axles done 2,000 miles ago (at the same time as cranking t bars to level height. This admittedly is when I first hear the problem. But thought I’d wasnt hearing it because bad CVs masked it)
-Wheel bearings done at 200k
-Tie rod ends done around 195k
-Upper + lower control arms, rack + pinion done at 190k
-Stablizer bushings, sway bar bushings, FR link assy done at 165k
-sway links at 130k

It (something in the front passenger side) makes kind of a popping, knocking, clunk in a variety of circumstances, mainly: hard-ish right or left turns over speed bumps, sometimes just regular driving over speed bumps (other times nothing!), sometimes when I set AHC down it’ll make the pop at the very bottom, sometimes just stepping on the passenger side running board will make it pop.

The noise did change after they installed the new shocks. It’s slightly more infrequent, but still definitely there.

 

[Das Shtig]

Wait.....so you spent $800 at the deslership and they didnt give you a definitive answer? AKA they lied to you about front shocks???? Remind me not to go to that stealership, ever. Your ahc should not be making any audible noise from the front end. Period. There are no front shocks as has been said before. My $0.02 is on a bushing, a brake dust shield, or another bushing.

What EXACTLY did you spend $800 on?

Sodomy? Apparently...

 

[Das Shtig]

I’ll raise hell about the front shock replacement. I’m pissed. The service manager was very rude to me today to add insult to injury. Told me I was gonna need to pay him more to continue to diagnose it, even though my $800 yielded nothing... ugh. And then said “well, it’s got 215k miles...” like this wasn’t a land cruiser.

 

[flintknapper]

Sounds like a front diff bushing.

Front diff bushing replacement?

 

[Das Shtig]

Did the diff bushing at 200k

Sounds like a front diff bushing.

Front diff bushing replacement?

 

[DirtDawg]

Check control arm bushings? Ball joints? I see you mention sway bar linkage above, was every piece replaced (bushings etc)?

Edit: see you did upper lower control arms. Did you replace frame bushings when this was done? I guess that also rules out ball joints

 

[Das Shtig]

Edit: Oops accidental post

 

[MongooseGA]

I have a god-awful creaking sound coming from what I think are my front shock mounts. I came in here to suggest that but it seems you've got a different problem.

I'd say control arms, but you've already done them. Toasted ball joints can cause 'popping' noises if I'm not mistaken. I haven't had them do any 'clunking' though, I don't think.

 

[Das Shtig]

Check control arm bushings? Ball joints? I see you mention sway bar linkage above, was every piece replaced (bushings etc)?

Edit: see you did upper lower control arms. Did you replace frame bushings when this was done? I guess that also rules out ball joints

I’m showing my sway bushing kit was 6 pieces.

I’m not sure what “frame bushings” refer to exactly?

 

[Das Shtig]

I have a god-awful creaking sound coming from what I think are my front shock mounts. I came in here to suggest that but it seems you've got a different problem.

I'd say control arms, but you've already done them. Toasted ball joints can cause 'popping' noises if I'm not mistaken. I haven't had them do any 'clunking' though, I don't think.

It’s more of a pop now that the front “shocks” got replaced. Was more of a clunk before. I’m going to try to figure out if I did my ball joints...oh I guess they’re kinda part of the control arms? So they’re good.

 

[DirtDawg]

I’m showing my sway bushing kit was 6 pieces.

I’m not sure what “frame bushings” refer to exactly?

There are the sway bar linkages that have 2 sets of bushings in them. These connect the sway bar to the control arm. Then there are “D” bushings that attach the sway bar to the frame. If these are shot they definitely can make some noise.

Did you install OEM upper/lower arms? I’ve definitely had balljoints make a range of noises from popping to banging if loose enough.

 

[Das Shtig]

There are the sway bar linkages that have 2 sets of bushings in them. These connect the sway bar to the control arm. Then there are “D” bushings that attach the sway bar to the frame. If these are shot they definitely can make some noise.

Did you install OEM upper/lower arms? I’ve definitely had balljoints make a range of noises from popping to banging if loose enough.

OEM everything.

Here’s I think the related parts as I have record of them:
-(x2) FR Link Assy 4882060032
-(x2) Stabili Bush 4881560111
-(x4) Sway Bar Bush 9094801003
-(x2) Sway Bar Bush 4884960010

 

[BadReligion]

If you have 215k mi on the original steering rack, those bushings (and the rack itself) could be a potential source of your mystery noise.