AHC Ride Comfort - New Owner (1 Viewer)

[AppleTech]

So I just replace all the fluid in the system following the great write-up here. Fresh clean fluid coming from all actuators and the accumulator. Ride comfort on the truck seems good (as far as I can tell - I have nothing to compare it to) - but I'm getting quite a bit of acoustic "thuds" when hitting light bumps. I'm presuming this is something like bushings as opposed to something with the shocks or AHC dampers. right?

Truck has 131K on it and doesn't appear to have been offroaded. Just got it a few weeks ago so I haven't really torn into the suspension. Thoughts appreciated!

 

[marshotel]

"Acoustic thuds when hitting light bumps," after 131 k miles sounds like it could be the shock bushings, or maybe the anti-sway bar linkage.

My experience is with a 1998 LC (no AHC), but my acoustic thuds went away after replacing the shocks and bushings and the sway bar linkage bushings. it sounds like you are on the right track.

hope this helps.

 

[looking4lc]

Same issue here. Planning to replace the fluid and check the bushings.

You may want to check the front pressure and adjust the TB.

 

[CanadianRockyCruiser]

If it's from the rear, I'd recommend checking the upper and lower control arm bushings. Replacing mine made bumps significantly less noticable. I'd like to replace the bushing in the AHC shocks in the future, but have yet to do so.

 

[Swisscheese]

Same issue here. Flushed entire AHC-Fluid, checked bushings and i get 7 grads on the ahc-container. The ride doesnt really feel different between comfort and sport. is there a way how i could see the difference between the two (four) modes?

 

[PADDO]

In your initial build thread you got lots of platinum standard advice regarding your AHC from @uHu. Have a reread of his words of wisdom and you'll have a way ahead.

 

[Swisscheese]

you are right @PADDO, @uHu and yourself as many others have provided excellent help during my build and getting things done the right way. i didnt think i would find any information in my thread regarding the ride quality as i have read all of it several times. anyway, i read through all the pages again and still dont know the answer to my question, it hasnt been addressed so far. since it is a minor problem but one that keeps my mind to it, i thought i would bring it up in this thread which i found during my research. be assured, i do not ask stuff twice just to make sure, but i ask stuff which i find important. as this one above. it has been discussed several times in several threads, but in not one i found a way to verify the correct working order of the sport/comfort setting. or if there even is a way to verify. or if it the answer is a part of the techstream-search im going to do. i simply do not have the knowlege to assume stuff, so i have to ask.
i do not mean to be rude, but i hope you understand my point.
now is a good time to thank you, @uHu, and all the others again for the help i recieve which really does help a lot! Cheers

 

[PADDO]

Fare enough, here's what you can do: in Techstream you can monitor the status of SW1 and SW2. These two inputs to the ECU are switched via the comfort setting dial from comfort through to sports 2, they toggle between on/off - you can confirm that the ECU is receiving the correct signals from the AHC selector in the center console. Next is to put the system in test mode and verify that the 4x damper assemblies are receiving and responding to the ECUs outputs. You start at damper position 1 (softest) up to 15, the hardest. You physically step the system through their damping settings whilst parked and hopefully feel the compression/rebound force change at each corner with each step. All this relies on your neutral pressures being good. You've got a diesel and @uHu would need to confirm its the same test procedure (short Ts and E1, start vehicle and step on brake to step the damping up) to petrol obd2 trucks.
HTH

 

[Swisscheese]

Thank you. i will try this procedure as soon as i get my hands on a techstream. i will report on my thread regarding the results and questions which might have popped up.
i'm hoping to do this next month in a friends garage where i can lift the car and adjust the TBs and see whether a spacer for the rear is needed or not. looking forward to get to it!