Help Me Fix My 2013 LX Loose Front End Part 6 (1 Viewer)

[Zjohnsonua]

OK. While AHC is more complicated than a traditional coil spring, it is still an engineered system with troubleshooting steps. Unfortunately, they do require someone with a little bit of give-a-damn to be involved in their execution, and it also also helps if they know how a chassis works before they test drive it. Do not take that last part for granted.

It seems you're on the right track with the globes. However, have your tech perform the system checks before performing the service. These things have operational ranges...not hard limits. Don't throw more good money after bad unnecessarily.

 

[TeCKis300]

My issue is a significant loose feeling through the steering wheel and significant movement of the steering wheel over bumps causing instability in the front end. It gets worse going from sport to comfort. Also the truck has become way more floaty. Bad accumulators are the next suggested culprit which I have on order. I hope that significantly improves my situation.

It’s hard to tell from that video, but his steering wheel seems to just have significant vibration while driving even on smooth roads. Not sure if we have the same issue or not.

I presume they inspected and checked for play in the suspension? Either bearings, tie rods, steering rack, ball joints. Those would be the obvious things any mechanic will know how to check.

Globes on the other hand are a mystery to them. I still strongly believe it's the source of your problems. You'll have very little damping and compliance to absorb any irregularities in the road, and the forces manifest in the chassis, steering, and general instability.

 

[milellie111]

I presume they inspected and checked for play in the suspension? Either bearings, tie rods, steering rack, ball joints. Those would be the obvious things any mechanic will know how to check.

Globes on the other hand are a mystery to them. I still strongly believe it's the source of your problems. You'll have very little damping and compliance to absorb any irregularities in the road, and the forces manifest in the chassis, steering, and general instability.

Oh yeah I’ve had the suspension checked by two Lexus dealers and 3 independent shops. All said everything was tight and no visibly worn parts. I replaced upper and lower control arms and outer tie rods at suggestions of forum. My Indy said there were actually some stress cracks on the bushings once they were off and yes my steering response improved but did not solve my original issue.

Really hope it’s the accumulators. Are bad/worn globes essentially bad shocks on a non AHC vehicle? What purpose does the actual “shock” serve on an AHC vehicle of all dampening and stability control are done by accumulators?

 

[grinchy]

I don’t think accumulators will fix steering wobble. They are the large dampers in the system; so address body roll and big hit compliance (instead of two or three body oscillation after a bump new accumulators damp better and there is one or two oscillations). By oscillation I mean that up and down body motion.

 

[Zjohnsonua]

Are bad/worn globes essentially bad shocks on a non AHC vehicle? What purpose does the actual “shock” serve on an AHC vehicle of all dampening and stability control are done by accumulators?

No. Globes are pre-charged reservoirs (there's a gas charge on the back side of a robust rubber diaphragm. AHC controls modulate the pressure on the working side of that diaphragm). They are intended to set the baseline stiffness that the rest of the system works from.

You've not specifically mentioned the condition of the steering rack bushings, or more directly, if the rack moves side to side when examined as the wheel is turned. You don't need to take the truck to a shop to do this. Have a helper turn the wheel back and forth while you look up at the rack. the rack should have no relative motion to the chassis. If there is, you need a rack as the bushings are not serviceable.

 

[TeCKis300]

Oh yeah I’ve had the suspension checked by two Lexus dealers and 3 independent shops. All said everything was tight and no visibly worn parts. I replaced upper and lower control arms and outer tie rods at suggestions of forum. My Indy said there were actually some stress cracks on the bushings once they were off and yes my steering response improved but did not solve my original issue.

Really hope it’s the accumulators. Are bad/worn globes essentially bad shocks on a non AHC vehicle? What purpose does the actual “shock” serve on an AHC vehicle of all dampening and stability control are done by accumulators?

Good to know and it would be clear if there is worn or suspect parts in the front end as they would manifest in play at the wheel. Including the steering rack bushings that would allow play at the 3 and 9 o'clock positions at the wheel that most mechanics know how to inspect for.

With blown globes, it's worse than no shocks to a regular car. The globes becomes just a filled dead headed vessel. Because the globes performs as part of the spring in the suspension, with out any compliance in the globe, there will be little to no flow of hydraulic fluid through the actual damping valve component, resulting in the added loss of damping. Minor note but there is some damping stack in the front shock, but its mostly a hydraulic ram.

Because the system is cross linked, there is still some compliance through linked paths to the other working globes in the system. That likely results in steering instability because of uneven suspension response.

Suffice to say, a failed globe will manifest in all sorts of what would be weird symptoms to classically trained mechanics.

 

[tbisaacs]

Good to know and it would be clear if there is worn or suspect parts in the front end as they would manifest in play at the wheel. Including the steering rack bushings that would allow play at the 3 and 9 o'clock positions at the wheel that most mechanics know how to inspect for.

With blown globes, it's worse than no shocks to a regular car. The globes becomes just a filled dead headed vessel. Because the globes performs as part of the spring in the suspension, with out any compliance in the globe, there will be little to no flow of hydraulic fluid through the actual damping valve component, resulting in the added loss of damping. Minor note but there is some damping stack in the front shock, but its mostly a hydraulic ram.

Because the system is cross linked, there is still some compliance through linked paths to the other working globes in the system. That likely results in steering instability because of uneven suspension response.

Suffice to say, a failed globe will manifest in all sorts of what would be weird symptoms to classically trained mechanics.

Just to concur here. My globes were absolutely shot when I replaced them at 130k. The truck rode so harshly and almost no dampening. It went from a little rough to very rough over the course of a week.

 

[grinchy]

From this discussion I would guess my accumulators weren't completely dead when I replaced them. I characterized the improvement at the time as 15% better.

 

[TeCKis300]

From this discussion I would guess my accumulators weren't completely dead when I replaced them. I characterized the improvement at the time as 15% better.

This is a great point. Globes aren't binary in that they're either good or bad. They can fail progressively by losing compressed nitrogen, reducing capability in volume and pressure. The other failure mode is outright rupture. In the progressive failure, it gets to a point that they only have limited "travel" before the membrane bottoms out. My guess is that @tbisaacs experienced a rupture. You were experiencing the globe bottoming out on occasion.

Globes bottoming out can also be exacerbated by AHC adjustments and setup. Namely too much sensor lift and weight on the AHC system. We've heard of people describing their setups to ride harshly in high after substantial sensor lifts. This is likely the result of globes bottoming out. Could potentially be mitigated by fresh globes, more support by the coil springs, or reducing overall weight.

 

[grinchy]

OP if you want to make a beer donation and pay shipping I have my not yet dead accumulators in a box. . .

 

[milellie111]

OP if you want to make a beer donation and pay shipping I have my not yet dead accumulators in a box. . .

How many miles?

I just paid $650 shipped from Japan for all 4 new even though they haven’t shipped yet

 

[TeCKis300]

How many miles?

I just paid $650 shipped from Japan for all 4 new even though they haven’t shipped yet

Dang, that's lower in price than I last looked! Surely cheaper than any aftermarket suspension fix.

I'm not experiencing any issues, but for that price, I should do this as I work my suspension pretty hard with all the towing weight.

 

[sadovnik]

thinking about a 2011 g550 to replace my 2013 lx. thoughts overall on reliability? had an 05 500 years ago. Don't mind the ride, it rolls less than my lx but I didn't have the 05 long enough to know about reliability. 2011 550 would have about 70k miles.

I've had two Gs, a 2008 G500 and a 2010 G55. They were both extremely reliable. Over the 3+ years I owned the G500, it had zero failures. Over the 2 years I owned the G55, it had two failures that could not be attributed to the car itself as they could have happened to any car. One was a bad fuel pump due to a ton of debris in the fuel tank (Garbage in - Garbage Out). The second one was a failed Fox adjustable shock absorber. I honestly could not fault the car for either of those failures. It's just a bulletproof platform and that 500hp-supercharged engine is orgasmic. BTW, Fox shocks are garbage. Don't ever use them if you value your life, IMHO.

 

[Romer]

Lets keep this thread on the Thread starters issue so it doesnt go off track again

 

[grinchy]

OP if you want to make a beer donation and pay shipping I have my not yet dead accumulators in a box. . .

I don’t have their full history, but at most 215k miles. At best maybe half that.
As the nitrogen leaks past the bladder over time, I feel like it is more about how old than how many miles. So 12 years or maybe six years old.

 

[milellie111]

Update….

So I had my shop replace all 4 accumulators (front and rear), 2 front OEM shocks with shock mounts and support bushings, and did a full fluid flush.

The truck rides much better! A noticeable improvement in dampening and ride control over bumps. The ride is so much more composed and predictable and the front end feel over bumps is much better. I am satisfied with the ride and this truck is a keeper.

I am glad that I kept investigating this instead of giving up. It was well worth it! I saved a ton of money buying OEM parts online and cross shopping for the lowest price. I knew something was definitely off in the front end when it was hard to keep control of the vehicle over road irregularities and the truck wouldn’t stay balanced after hitting a bump.

Thanks to all for the helpful suggestions and providing your expertise.

 

[Romer]

Really appreciate your coming back with the answer. Too many times these things are open ended with no resolution even if the user found one.

You have paid it forward and helped others by doing so.

Congrats on sticking with it and resolving your problem

 

[PDoyle]

Do you feel a significant difference when you switch from comfort to sport?

 

[milellie111]

Do you feel a significant difference when you switch from comfort to sport?

Yes. Comfort is no longer extra bouncy. It’s still a little floaty but in a "comfort" sort of way. Before it felt "loose", now it doesn’t. Sport is not Mercedes AMG/BMW like handling. It’s still comfortable with slightly better steering response and tightness than Normal mode. Sport is not harsh at all.

 

[milellie111]

Really appreciate your coming back with the answer. Too many times these things are open ended with no resolution even if the user found one.

You have paid it forward and helped others by doing so.

Congrats on sticking with it and resolving your problem

Thank you. I am glad to be a part of this forum so I felt obligated to report back. After all, that’s what forums like these are for. To share an interchange of knowledge and experiences. I knew my LX was not riding right. I was motivated to find the issue.

Used car prices right now are through the roof. Even all the money I spent figuring this out does not come close to the time and price I would have spent selling and buying something equivalent.