Front end rebuild Harsh over bumps

[brh11]

So I finished rebuilding the entire front suspension down to everything but the knuckle and hub. But going over bumps or especially speed bumps it feels like the front end is slamming into the ground from how hard the impact is. I can almost feel every little bump and big ones just have such an impact it’s scary. Before getting an alignment I figured it was just very horribly aligned( which it was) but now that it’s in spec it’s doing the same thing


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[Foggy]

Which components did you use???
Did you put weight on the susp before torqing down the control arms??
Did the alignment guy see anything suspicious???
Give us some more details

 

[brh11]

Well here are a few details

I used everything from moog parts besides Delco factory electronic shocks and new r&p

Alignment guys said nothing but I have faith in it being either coil springs or tires.
Coils looked pretty good when putting them on but I have a sense they might just be worn out from years of rough roads and use before I took hold of it.




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[kbuskill]

Well here are a few details

I used everything from moog parts besides Delco factory electronic shocks and new r&p

Alignment guys said nothing but I have faith in it being either coil springs or tires.
Coils looked pretty good when putting them on but I have a sense they might just be worn out from years of rough roads and use before I took hold of it.




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Any suspension codes???

The shocks may be new but the control module may not be allowing them to soften up.

@iamdub can tell you more but I think he unplugged his front struts as a test and they got real soft but I can't remember for sure.

You could try unplugging them, just as a test, and take it for a ride and see what happens.

 

[iamdub]

Well here are a few details

I used everything from moog parts besides Delco factory electronic shocks and new r&p

Alignment guys said nothing but I have faith in it being either coil springs or tires.
Coils looked pretty good when putting them on but I have a sense they might just be worn out from years of rough roads and use before I took hold of it.




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Coil springs, including those around the struts, will ride softer when worn.

Any suspension codes???

The shocks may be new but the control module may not be allowing them to soften up.

@iamdub can tell you more but I think he unplugged his front struts as a test and they got real soft but I can't remember for sure.

You could try unplugging them, just as a test, and take it for a ride and see what happens.

Correct. I unplugged all four shocks and it was really soft, as in dangerously soft. Felt like really worn out shocks with no control. I went less than half a mile before I pulled over to plug them back in. The ride isn't horrible, but I know it should be considerably softer and it will be after I lower it with the Belltech shocks and struts.


@brh11, Was the ride as firm before you replaced the shocks? If you have new OEM electronic shocks and they ride the same or worse, then you may need to perform some kind of reset or recalibration on the suspension computer.

 

[brh11]

Just checked and nope no codes for the suspension

Ride is definitely worse then before, the whole front end ball joints and everything was in horrible condition previously so hard to tell exactly what was causing it but yeah feels like going over bumps that the whole front end is slamming down onto the road but hitting soft spots or smooth roads Feels pretty good but still too firm


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[iamdub]

Just checked and nope no codes for the suspension

Ride is definitely worse then before, the whole front end ball joints and everything was in horrible condition previously so hard to tell exactly what was causing it but yeah feels like going over bumps that the whole front end is slamming down onto the road but hitting soft spots or smooth roads Feels pretty good but still too firm


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I know how the system works in general, but not how the system processes. My thoughts are that it's still reacting as if the old worn shocks are still there. Now that you have new shocks, which are inherently firmer, they're gonna be even firmer with the controller telling them to firm up because it still thinks the old ones are there.

Unplug the front two or all four and go for a short drive. It's an easy 3-minute test.

*EDIT*

I just thought of something: Did you happen to spin the shaft any when installing the new ones?

 

[brh11]

Nope didn’t spin the rod but got some news

Breaking out the scan tool on the morning drive brought up some questions.Graphing the results on the front 2 shocks damper command I’ve found some odd results

The shocks seem to only have 3 values that they are damping the first about 18-25% for occasional small bumps but hitting two bumps in a row only throws the first command and not a second. Random 100% commands when there is no bump in the road at all, occurred about 6 times over 20 minutes. Stopped at a red light the command is about 25% and holds until I go on the green light

Possibly unrelated but now this morning I have a CEL for module communciation bus A off. But seeing as it is sending a command the odd time I’m ruling that out and probably something got disconnected from the super rough ride and I wouldn’t be surprised if it did

*edit*
Just disconnect the sensors and took it for a ride. Definitely softer suspension and better. Still hits too hard potholes and bumps but it’s a start

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[kbuskill]

Nope didn’t spin the rod but got some news

Breaking out the scan tool on the morning drive brought up some questions.Graphing the results on the front 2 shocks damper command I’ve found some odd results

The shocks seem to only have 3 values that they are damping the first about 18-25% for occasional small bumps but hitting two bumps in a row only throws the first command and not a second. Random 100% commands when there is no bump in the road at all, occurred about 6 times over 20 minutes. Stopped at a red light the command is about 25% and holds until I go on the green light

Possibly unrelated but now this morning I have a CEL for module communciation bus A off. But seeing as it is sending a command the odd time I’m ruling that out and probably something got disconnected from the super rough ride and I wouldn’t be surprised if it did

*edit*
Just disconnect the sensors and took it for a ride. Definitely softer suspension and better. Still hits too hard potholes and bumps but it’s a start

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Did you unhook the ride height sensors that have the rod connected to the upper control arm OR did you unplug the connector on top of the strut shaft?

 

[brh11]

Nope disconnected the electrical on the top of the shock


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[Doubeleive]

What scanner are you using? did it give a "service suspension system" message on the DIC? when you connected the struts back up are you sure you have the top connector on all the way? I had a loose connection crop up 3months after the struts were replaced, sure enough the connector was loose on the shock, a tech2 will give you a more specific code.

 

[cam3439]

Since you said you did a front end suspension rebuild, did you happen to change the swaybar endlinks? If so, make sure they’re not too tight. If they are, then they may not be allowing your suspension to absorb road bumps, etc.

 

[dwchapmanjr]

Since you said you did a front end suspension rebuild, did you happen to change the swaybar endlinks? If so, make sure they’re not too tight. If they are, then they may not be allowing your suspension to absorb road bumps, etc.

I've been trying to do a bit of reading on this and can't seem to find any definitive information on this. I worked on a project to replace my front struts that involved loosening the links. I accidentally torqued them to 37 after completing instead of 17. I have this terrible road vibration where I can feel every road bump but I was having this issue before I loosened it so I'm hesitant to adjust, particularly if there's any issue backing off the torque on it when already set to that torque.

Curious if OP ever figure out the issue.

 

[Mateoo]

Did you find out what was causing this? I have the same issue.

 

[petethepug]

@brh11 kinda disappeared last year. He never advised what kind of active struts he installed or what they’re installed on.

A little digging shows an 09 Denali so he should have purchased z55 replacements that are filled with hydraulic fluid. If he purchased z95 Magneride for 09+ Escalades he will have a horrible experience. His suspension control module won’t know when NOT to energize the mag fluid so the struts could be in a permanent state of full blown full firm.

 

[FAUST]

I have the same issue with my 07 Tahoe - I too replaced the front end components - upper and lower control arms with ball joints, inner outter tie rods, Arnott strut assemblies, sway bar linkage and bushings- everything but the hub/knuckle.

The trim is LTZ and is z55.

This was my first repair job so its entirely possible I simply purchased the wrong components. This truck has the sensors but I dont ever feel or notice any change in ride. I only notice the rear air shocks adjusting based on load weight.

Ill take any ideas to check this out - it is driving me nuts - I also fear its been so long that Ill likely need to replace the strut assemblies again to get the right ride.

 

[FAUST]

Doing a quick VIN search - Im getting the trim as LS and LTZ - any suggestion on where to decode VIN for most accurate info would be appreciated.

 

[Marky Dissod]

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[FAUST]

Here is what I installed

Arnott MyCarParts

I am not sure if the OE is different - the one above has a bypass for the active part - my RPO is 6BM and 7BM - which I am not confident in my search as to whether or not its supposed to be an active suspension.

I conclude based on the equipment on my truck - the active ride sensors - that in fact it should be active.

Does anyone have any insight on this for me?

I am curious if there is a step I am missing when using the parts above that bypass the active suspension. I am also concerned this long standing issue has worn the strut assembly and needing to replace it.... again.