BDS 6" lifted 2019 Denali adaptive ride not functioning

[Andrew Therrien]

Hi guys, as the title says, 2019 Denali lifted with a BDS 6" made for the adaptive ride.  Truck rode exactly the same as stock for about the first 10k miles. Now it rides as if the shocks aren't working at all, front tires are bouncing all over the place on bumps and bridge abutments send the truck all over the road.  Truck has been completely gone thru as far as re torquing bolts, even replaced the front struts (not cheap) with no improvement. Dealership is useless and want nothing to do with it so I figured I'd ask here. Buying new sensors for the adaptive ride now to try that. No lights on the dash or anything also. Brand New tires and freshly aligned.  Basically last resort here. Bummer because the truck rode like new at the beginning, definitely feels as though it's an electronic issue preventing the shocks from adjusting as they should!

Any help appreciated! Thanks

[topgear1224]

Were the tires before or after the issue started?

What are your cold tire pressures?

What tire and wheel size?

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[Andrew Therrien]

3 minutes ago, topgear1224 said:

Were the tires before or after the issue started?

What are your cold tire pressures?

What tire and wheel size?

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Thanks for the reply! The tires were installed at the same time as the lift.  They're 35x12.50-22 ridge grapplers on stock Denali wheels. Tire psi is 33lbs give or take a couple. 

[topgear1224]

Thanks for the reply! The tires were installed at the same time as the lift.  They're 35x12.50-22 ridge grapplers on stock Denali wheels. Tire psi is 33lbs give or take a couple. 

What load range? C,D,E might also be expressed as service description such as 111T (stock load range)

You will need the tire load chart showing load capacity at various PSI for your specific tire. You need to match the PSI to what's listed for 2,409lbs (again stock tire load index) NITTO should be able to get this information for you.

When you change size the OEM pressures are useless unless you retain the same load rating and design (111 in this instance)

If it's getting squirrelly (feels like it wants to dart around even with the steering straight), its likely one of the wear components in the front end. My bet would be tierods. (Just a guess, don't keep throwing parts at it)

Did they set the alignment to OEM specs or BDS's recommendation? On a non double wishbone suspension as it cycles the alignment angles can change this can lead to some interesting handling over bumps.

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[Andrew Therrien]

11 minutes ago, topgear1224 said:

What load range? C,D,E might also be expressed as service description such as 111T (stock load range)

You will need the tire load chart showing load capacity at various PSI for your specific tire. You need to match the PSI to what's listed for 2,409lbs (again stock tire load index) NITTO should be able to get this information for you.

When you change size the OEM pressures are useless unless you retain the same load rating and design (111 in this instance)

If it's getting squirrelly (feels like it wants to dart around even with the steering straight), its likely one of the wear components in the front end. My bet would be tierods. (Just a guess, don't keep throwing parts at it)

Did they set the alignment to OEM specs or BDS's recommendation? On a non double wishbone suspension as it cycles the alignment angles can change this can lead to some interesting handling over bumps.

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Understood, as far as air pressure.  This has been the same pressure since the install. Practically zero wear and tires rotated every oil change.  Entire front end gone thru and inspected with virtually no wear.  Alignment was to BDS specs which is identical to stock, as this suspension system drops the entire diff/steering which maintains exact factory steering/suspension geometry.  Honestly couldn't even tell the truck was lifted when driving after the install.  Going down a rough road while hanging out the window, the tire is bouncing up and down very similarly to bad shocks/struts on any other vehicle. Hence why I'm trying to see if anyone had any electronic issues with the adaptive ride.   All the basic common knowledge issues such as air pressure, wear items in the front end such as tire wear, ball joints, tie rods, struts have been very well inspected and or replaced.  With geometry being identical to stock, alignment is correct.   

[topgear1224]

There's different specs for 17-20 and 22 in wheels on the new GM platform. Wonder why they chose the more aggressive 22in spec. (Ultimately irrelevant to your issue, but nevertheless)

Tire wear only indicates that either the tires extremely well constructed and it footprint is compensating, or that your pressure is not drastically wrong but it doesn't necessarily mean that it's the right pressure. This is fairly common on higher load range tires.

If you replaced the struts already, once you do the sensors the only other thing it could be is the springs. (Which unless they are cheap Chinese steel I doubt is the issue)

if it's just the front two hopping have you tried putting the front on the rear? Maybe the sidewalls are internally separating.

I was riding behind a 2019 Silverado the other day and I noticed that over the sharper small bumps that the rear tires are actually bouncing like basketballs. But he was unloaded and it would be weird to have that issue on the front with all the weight.

Here's how I would approach it I would start with the tires. I would first try rotating is it's going to be the easiest. (Assuming you do it your self, torque is 140LB-FT)

it's a problem remains on the front next I would play with pressures. a short 5 to 10 Mile test drive should be all you need.

Inflate the tires when COLD to their max PSI. See if the problem gets worse or better. Do note that the ride is going to be extremely rough and it's likely that the vehicles going to feel a bit edgy to steering inputs. the only thing you're looking for is to see if the bounce gets better or worse.

Then I would try lower pressure, I wouldn't go super low, 28-30psi should tell you what you need.

Sometimes with oversized tires you have to kind of go a bit custom but I would never recommend going below the OE load rating on psi for safety.

I would suggest you do the PSI changes to all four wheels. although you'll get better more accurate results with just the front wheels. if you find yourself in an emergency situation and have to slam on the brakes your braking performance is going to be greatly reduced with different PSI front and rear.





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[topgear1224]

Wait who did you have install the Lift? if they torqued all the bolts with the suspension at full droop (on the lift) it's going to act like it has higher rate springs in it till the bushings eventually tear or loosen up.

I've been reading a lot of lift kit instructions so it's kind of muddy but all of them say the final torque needs to be done with the vehicle suspension settled after rolling it 10-15 ft front and back.

This would give a more control to ride with less movement. In essence it's going to force the sidewall to act like the spring. this would give a ride very similar to when the truck is brand-new before the suspension breaks in.

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[Andrew Therrien]

2 minutes ago, topgear1224 said:

Wait who did you have install the Lift? if they torqued all the bolts with the suspension at full droop (on the lift) it's going to act like it has higher rate springs in it till the bushings eventually tear or loosen up.

I've been reading a lot of lift kit instructions so it's kind of muddy but all of them say the final torque needs to be done with the vehicle suspension settled after rolling it 10-15 ft front and back.

This would give a more control to ride with less movement. In essence it's going to force the sidewall to act like the spring. this would give a ride very similar to when the truck is brand-new before the suspension breaks in.

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I will definitely try out the air pressure changes along with the rotation! And a reputable shop in town did the lift install.  I will ask and be sure they did this but I have no doubt as they've done a lot of these installs (not specifically Denali but same principle)  the truck was brought in about a week after install to retorque everything also and to add to the bushing idea, with the adaptive ride, I feel as though even IF the bolts were torqued on the lift and broke down over time, the adaptive ride would automatically compensate for the "looser" travel and adjust as so to maintain factory ride quality.  I can't see the bolts being torqued while lifted causing such a drastic change in ride quality ESPECIALLY with adaptive ride adjusting shock valving on the fly.  Realistically the only bolts that would've effected that are the upper and lower spring/strut bolts and control arm bolts, which both have sleeves in the bushings anyway, so it's not preloading the bushing at all, seeing the rotation is the sleeve inside the bushing.  But I'm willing to try anything at this point haha thanks for the input 

[topgear1224]

It's the control arm ones and when you bolt them down it actually squeezes the crossmember tight against the bushing. The inner sleeve is to prevent the bolt from binding. The outer is to prevent massive deflection that could spot load the bolt leading it to fail.

I only bring it up because it's much easier to torque all the bolts underneath the truck on a lift then it is to get down on your back and try to torque them on the ground.

The new adaptive ride control is not mag ride like the old denalis. It's a new cheaper version with just valves in the shocks.

Mag ride in theory was infinitely adjustable. (See Camaro ZL1) you can make the shock as stiff as bricks to limit travel or allow it to just simply slow the suspension movement as it reaches the limits of travel.

You still need to have a good base spring rate but you have the ability, in theory, to tune the vehicle for near zero body roll in sport mode, then have it float like a Mercedes S Class on the highway in tour.


the new system cannot do that, all it can do is add a bit more or a bit less dampening. The stock wheels are heavy due to their size, and are paired with a very light tire. This limits the overall rotating Mass. Going to 35s likely doubled the weight of that tire. Meaning those valves are likely full closed once suspension gets moving.

where you're likely experiencing the bouncing is in the dead zone that GM builds in for that cushy ride quality where the valves are in a neutral state. Bear in mind this is just a theory but it does align with the symptoms you are experiencing. Does it go away in sport mode? If not you may simply be exceeding the capability of the shocks.

The other issue and major problem with variable valving inside a smoothie shock is aeration, without a remote reservoir with it's extra piston, that shock fluid will definitely mix with the gas. Fluid aeration is the most typical cause of shock fade.

Another drawback that mag ride does not experience is valve deflection. this is where the valving in the Piston is actually deflecting and allowing more oil then it was intended to to pass through.

It's a shame really because mag ride denali's, even with massive 22 inch wheels, rode like a vehicle from the 90s (lots of sidewall) but handled like a modern car.

I'm sure ARC will be much more reliable than mag ride due to its much more simplistic nature, but I feel from an engineering standpoint it's definitely a step backwards.

the sudden change you experience combined with the fact that replacing the shocks did not help anything makes me lean towards the bushings. it could be the sensors but I kind of feel like that would have been the first thing to be replaced rather than the second. Also I would assume the dealership has an ability to function test them with their scanners.

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[Andrew Therrien]

2 minutes ago, topgear1224 said:

It's the control arm ones and when you bolt them down it actually squeezes the crossmember tight against the bushing. The inner sleeve is to prevent the bolt from binding. The outer is to prevent massive deflection that could spot load the bolt leading it to fail.

I only bring it up because it's much easier to torque all the bolts underneath the truck on a lift then it is to get down on your back and try to torque them on the ground.

The new adaptive ride control is not mag ride like the old denalis. It's a new cheaper version with just valves in the shocks.

Mag ride in theory was infinitely adjustable. (See Camaro ZL1) you can make the shock as stiff as bricks to limit travel or allow it to just simply slow the suspension movement as it reaches the limits of travel.

You still need to have a good base spring rate but you have the ability, in theory, to tune the vehicle for near zero body roll in sport mode, then have it float like a Mercedes S Class on the highway in tour.


the new system cannot do that, all it can do is add a bit more or a bit less dampening. The stock wheels are heavy due to their size, and are paired with a very light tire. This limits the overall rotating Mass. Going to 35s likely doubled the weight of that tire. Meaning those valves are likely full closed once suspension gets moving.

where you're likely experiencing the bouncing is in the dead zone that GM builds in for that cushy ride quality where the valves are in a neutral state. Bear in mind this is just a theory but it does align with the symptoms you are experiencing. Does it go away in sport mode? If not you may simply be exceeding the capability of the shocks.

The other issue and major problem with variable valving inside a smoothie shock is aeration, without a remote reservoir with it's extra piston, that shock fluid will definitely mix with the gas. Fluid aeration is the most typical cause of shock fade.

Another drawback that mag ride does not experience is valve deflection. this is where the valving in the Piston is actually deflecting and allowing more oil then it was intended to to pass through.

It's a shame really because mag ride denali's, even with massive 22 inch wheels, rode like a vehicle from the 90s (lots of sidewall) but handled like a modern car.

I'm sure ARC will be much more reliable than mag ride due to its much more simplistic nature, but I feel from an engineering standpoint it's definitely a step backwards.

the sudden change you experience combined with the fact that replacing the shocks did not help anything makes me lean towards the bushings. it could be the sensors but I kind of feel like that would have been the first thing to be replaced rather than the second. Also I would assume the dealership has an ability to function test them with their scanners.

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Excellent info! Thank you I was aware the difference between mag ride and the dampening adjustment of today but didn't take into consideration the tire size/weight being so critical.  Again thanks for the input!

[topgear1224]

To be clear replacing the bushings will not solve your problem. If it was in fact torqued at full droop, replacing the bushings, and torquing the suspension correctly at normal ride height Is likely going to get you back to where you are now. Just with less squirming.

if it was the bushings this is simply how your truck is going to ride with 35s unless you replace the shocks with something like king 2.5s that can handle dampening the additional unsprung weight.

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[topgear1224]

The ultimate test would be to replace the 35s with your OEM rubber and see if the problem goes away. If it does you know it's something either to do with the tire (psi load, rating, design) or with the unsprung weight.



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[Denali_Brad]

Any update? This is the lift I wanted until I read this.

[jbshoo]

Me too but I was opting for the 4 inch vs six so I can still get it in my garage

[mdfinest]

I was also considering the 6" lift so I am here for the updates