DallasDave

iTrader: (1)

For those of you keeping score at home, here's some more photos and comments.

This is the front shock with the adjustment motor removed:



With the motor sitting next to it:





And it appears that the rear shocks are the same:

DallasDave

iTrader: (1)

I'd love to know how spoogenet knew that the motor travel was 115degrees...I think that's absolutely accurate.

In any case, the normal motor position seems to be at the limit-clockwise (viewing the motor installed from a "bird's eye"). So I am assuming that Sport+ might have the motor move to the limit-counterclockwise. I'd love to hear from someone who actually knows about these units.

For some reason the dealership won't have my car ready until Saturday, so I'm enjoying dismantling their loaner until that time. This may be a wild goose chase (I've been there before), but I am hopeful that this information will help me troubleshoot my car's rough riding problem. All along I told them it seemed like it was stuck in Sport+ mode and/or the rear shocks were way too stiff (malfunctioning). I was quite disappointed when their diagnosis was "everything is normal". I'll give anyone 3-1 odds that the service technician just took it for a spin and never even looked at anything closely. My instinct tells me that it will be one of the following: motor(s) are dislodged from mount (just like the loaner car had), motor(s) disconnected, failing motor(s), or bad shock(s).

If you have some familiarity with these shocks/adjustments, PLEASE chime in...but all comments are welcome.

peteharvey

spoogenet

I got the 115deg from a Google search. It found this thread from the IS board: https://www.clublexus.com/forums/sus...pension-2.html

I presumed that Lexus would reuse their technology across product lines. Unfortunately that's about as deep as I could find on the details.

I don't know enough about the inside of their shocks to know how easily it can go 'bad' in a way like this. Typical fail mechanisms for shocks are valve issues or leakage that causes them to lose their effectiveness and leaving the springs to do all the work, i.e. bouncy or sagging.

I do look forward to what you find on your car. Do you notice the stiffness mainly in the rear? Do you notice a difference when changing modes?

On your question about how/when it moves, another bite of into I found is the following (emphasis added by me):
From: https://lexusenthusiast.com/2011/11/...the-technical/

LatinLS430

iTrader: (1)

Any updates on this ??

DallasDave

iTrader: (1)

Yes, there's what seems to be a good update. So I picked up the car from the dealer on Saturday. They genuinely seemed to be interested in assisting me...that's not the impression I got a few days prior. They road force balanced the tires and checked air pressure, etc. They still came back with "no problem found" and "car operates normally" regarding the stiff suspension.

Driving the car home it was VERY easy to tell it was MUCH stiffer than the loaner GS F Sport I had been driving for almost ten days. When I got the car home I inspected the dampener motors and wiring. I seriously expected to find a fault/problem, but no luck. So I decided to "play around" with things in my own way. I manually moved the motors to the clockwise most position and disconnected the wiring from each. Took it for a spin and found out that this was the stiffest setting. So I then manually rotated all the motors to the counter-clockwise position (again, leaving the wiring disconnected). This is definitely the smoothest setting.

That's where things are today and I think that's how it's going to stay. So I lost AVS, but the ride if much, much, much more compliant...damn near smooth. I'm still surprised how much notice there is to expansion cracks and other small road imperfections, but overall I'm happy. My gripes are now minor, lol. My car isn't quite as "planted" at highway speeds (like the loaner and/or my previous two BMW 5 series), but that could be tires. So I'm just going to drive it for the foreseeable future and hope that I get accustomed to it (I think I will). If I ever sell my extra set of BMW wheels/tires, I may spring for a new set of "shoes" for the GS. Perhaps the Michelin AS3+ or something rated really quiet and smooth. We will see what happens...

peteharvey

Perhaps try and get a test drive of an used 2013 or used 2014 GS350 Luxury, and see how you like it?
It has 18" wheels and floatier true AVS shock absorbers - you may be find both softer than your 2015 with AVS shockies disabled.

Overall, the springs in the 4GS is still quite firm to limit roll, hence limit weight transfer to the outside wheels, for quicker steering response, sharper turn-in, and higher limits of terminal adhesion. Dunlop Sport Maxx 050 Summer Performance Tires don't help the ride either I guess.

The 2015 E Class has a much more compliant ride.
I haven't driven the 535i in quite a number of years, so I have forgotten just a little, but it is somewhere between E Class and GS.
However the A6 3.0T SuperCharged AWD is also very soft riding, but the AWD grips, grips and grips.

The Hyundai Genesis has a lovely ride too, but the badge, the styling, the fuel consumption, and the sheer size and bulk.
Jag XF is sharp handling, and quite firm too - if I remember correctly?
Not bothered to drive Infiniti Q70's, nor Acura RLX's - their styling is terrible IMO.
.

DallasDave

iTrader: (1)

I'm afraid if I drive a 2013/14 and like it better than my 15 I won't be able to live with it! So I am not pursuing. Regarding the 18" vs 19" wheels, I'll live with the 19" wheels. Not willing to give up the looks AND spend the money to get a set of comparable 18" wheels and tires. As I mentioned before, maybe a new set of tires that have a better rating (for smoothness/quietness) than the existing tires will be in my near future.