2016 Sierra Denali-2 month review

[Ron.s]

Turned on the garage heater and redo of my spring clamps today. First I removed them and drove around to let the springs take a set. Then I measured the free play at the end of the overloads and got the following:

Drivers side-front 1.50" rear .862" Passenger side-front .781" rear .833".Because of the spring edge bevel and the arc these could be off a little but you get the idea. For some reason the drivers front has more gap than the rest, too much to be in spec IMO. After installin the clamps there was no change in rear free play but the front is now touching the spacer/cushion whatever it's called.

Nothing had moved in 900 miles so I decided to put back the cheap set from Auto Zone until I decide to leave them permanently. I did put on some Loctite, flat washers and better lock washers. they are exactly 6" in front of the Plastic axle bushing.

While I was crawling around I remembered to check the torque on the axle U bolts. I didn't really check it but set torque at 70# and got about a full turn+ on each nut. Should have checked to see what factory spec is but they should handle 70 and probably more. I haven't used Photobucket in a while so getting error message on my pic's.

Edit:

The spring alignment is off a little or wider on the driver front leaf. My clamp is very snug there and loose on the other 3 positions front and rear. I really had no way to measure them without removing them.

[Ron.s]

Before:

 

After

 

[Smickie500]

Turned on the garage heater and redo of my spring clamps today. First I removed them and drove around to let the springs take a set. Then I measured the free play at the end of the overloads and got the following:

Drivers side-front 1.50" rear .862" Passenger side-front .781" rear .833".Because of the spring edge bevel and the arc these could be off a little but you get the idea. For some reason the drivers front has more gap than the rest, too much to be in spec IMO. After installin the clamps there was no change in rear free play but the front is now touching the spacer/cushion whatever it's called.

Nothing had moved in 900 miles so I decided to put back the cheap set from Auto Zone until I decide to leave them permanently. I did put on some Loctite, flat washers and better lock washers. they are exactly 6" in front of the Plastic axle bushing.

While I was crawling around I remembered to check the torque on the axle U bolts. I didn't really check it but set torque at 70# and got about a full turn+ on each nut. Should have checked to see what factory spec is but they should handle 70 and probably more. I haven't used Photobucket in a while so getting error message on my pic's.

Edit:

The spring alignment is off a little or wider on the driver front leaf. My clamp is very snug there and loose on the other 3 positions front and rear. I really had no way to measure them without removing them.

 

Following.....Thanks for the details

[Ron.s]

Quick update:

 

With another 500 miles on my vehicle, over 5500 now, I am convinced that just tightening the rear leaf spring U bolts solved 90% if not all of my vibration problem. My Mag shocks still don't seem to be working correctly there is some dampening but it's not happening at initial travel so stutter bumps are harsher than they should be. GM customer service made an appointment with my dealer to take a look at the suspension sometime soon. They contacted me after reading my posts or maybe as a result of the survey we all get soon after purchase. I've been delaying a dealer visit because of the intermitant nature of my issues and the policy requiring that the dealer must be able to observe the issue. The GM call should get things rolling with out proof?

 

My Android Auto seems flawless now and I love it except for plugging in USB vs Bluetooth. Not handy for short trips around town. Android pushed a phone update a few days ago and that seems to have solved the connectivity issues. I started by using the USB in the center storage compartment-out of sight less apt to get stolen. But kept leaving my phone so now use the other USB and the handy slots in front of the center console. But my phone was bouncing around so I made a retainer with Velcro straps than can be easily removed. Here's a pic....didn't notice all the dust until pic....great camera. There are two velcro loop straps attached to a small velcro piece on the covers, second one is for my wife's phone.

http://s212.photobucket.com/user/ronseewald/media/Phone%20clips%20Danali.jpg.html

 

Also here's how I used velcro to attach the mute for my radar detector.

 

http://i212.photobucket.com/albums/cc172/ronseewald/Escort%20Mute%20Denali.jpg

[Ron.s]

I forgot to mention one new discovery about Android Auto. It uses Satelite for navigation when you lose the cell signal. Traveling through central Nevada there are numerous stretches with no cell service. I noticed my screen flicker a few times and then saw that the inductor in the upper right corner had changed to a Satelite dish from 4G or 3G. During a longer stretch on Satelite I also found that none of the search functions worked. I.e. Nearest gas, nearest restaurant, etc. At least for now it seems that AA Google Nav only supports maps when you hit dark cell areas. I assume that the other music service such as Amazon wouldn't work either. Not a big deal but interesting how GM has leveraged the Satelite portion of Onstar. I had expected that AA would download more mapping detail to the vehicle so that it could still provide maps in dark spots. Maybe coming in the future! This may be why some other auto co's are slow to implement AA.

[phabejhmoob]

I had expected that AA would download more mapping detail to the vehicle so that it could still provide maps in dark spots. Maybe coming in the future! This may be why some other auto co's are slow to implement AA.

 

Did you know you can download portions of maps ahead of time onto your phone in Google Maps? This is to ensure you have maps while not having cell service. https://support.google.com/gmm/answer/6291838?hl=en

[Ron.s]

 

Did you know you can download portions of maps ahead of time onto your phone in Google Maps? This is to ensure you have maps while not having cell service. https://support.google.com/gmm/answer/6291838?hl=en

Yes but that's not a current function with Android Auto. Once you plug your phone in USB then the phone is disabled and a slave to AA vehicle.

[phabejhmoob]

Yes but that's not a current function with Android Auto. Once you plug your phone in USB then the phone is disabled and a slave to AA vehicle.

 

Interesting, i'll have to try this sometime. Turn off Wifi, connect AA and navigate. See if it will work without any data connection.

[phabejhmoob]

 

Interesting, i'll have to try this sometime. Turn off Wifi, connect AA and navigate. See if it will work without any data connection.

 

so I tested and downloaded a map for my metro pdx area, it works offline as I had turned off both Wifi (so it won't use car's wifi) and LTE, bascially no data except calls and text and I can navigate perfectly fine. So I would assume when traveling to areas without cell (LTE, data service) it would work. As long as GPS isn't turned off on the phone it should work with the downloaded map on the phone .

[camcamaro1991]

Hey Ron I just took delivery of my new 2016 Sierra Denali I noticed they added some "inserts" between each of the rear leaf springs and used a X clamp/under the axle for the U bolts. Does yours have this? really like the auto fold mirrors when holding the lock button, got to turn the option on in your infotainment screen.

 

I can take pics later, its getting window tint and clear bra for the paint protection.

[Ron.s]

so I tested and downloaded a map for my metro pdx area, it works offline as I had turned off both Wifi (so it won't use car's wifi) and LTE, bascially no data except calls and text and I can navigate perfectly fine. So I would assume when traveling to areas without cell (LTE, data service) it would work. As long as GPS isn't turned off on the phone it should work with the downloaded map on the phone .

That's good to know. I downloaded the map for Nevada area without cell service and will test that in about a week when I get back to Nevada. AA needs to do this for us at some future date. It's almost impossible to anticipate where you will lose service when on a long trip in an unfamiliar area. And in the west you may lose service in a well covered area when you drop into a valley surrounded by mountains. Switching between satellite and cell works OK but the screen goes blank for a second each time so it's a little distracting.

[Ron.s]

Hey Ron I just took delivery of my new 2016 Sierra Denali I noticed they added some "inserts" between each of the rear leaf springs and used a X clamp/under the axle for the U bolts. Does yours have this? really like the auto fold mirrors when holding the lock button, got to turn the option on in your infotainment screen.

 

I can take pics later, its getting window tint and clear bra for the paint protection.

I don't have any inserts between the springs and no X clamp. There is a spacer(cushion at the overload tip). Mine has aabout a 1" spacer on top and and a steel bracket below that that is flat on top and tapers around the axel. On the bottom is an H clamp that also is tapered around the axel. I'm guessing that this is to reduce the chance of getting any movement (axel wrap). I think this is changed from my 14 but don't know for certain. I read that the 16's have different body mounts than 14-15.

I have a dealer appointment Monday so will see what they find. I did get a PM from GM customer service and they opened a case number so maybe the dealer will be OK to actually do something.

[Ron.s]

My dealer visit went as they usually do....Nothing done. We went for a test ride and then took another 16 for a ride. We weren't in an area to reach speed that causes the truck to vibrate but at 70 on a rough patch mine was getting the shakes...not a good ride. The tech said "boy if it got much worse that would bother me". I said that at 80 it gets lots worse and this isn't even that bad of road. The other 16 was worse and of course GM has the dealer benchmark issues comparing mine to another truck. If any issue is like another one then it's working as designed.

 

But I learned a few things that might help others.

1. They claim there is no way to check Magneride shocks to see if they are working properly. I don't believe that can be true but that's the story I got.

2. There is also no way to check to see that U bolts are torqued properly. The factory spec is torque to 59# in a crossing pattern and then torque each again 130 degrees in the same pattern. Once torqued in this way the bolt has theoretically stretched a few thousandths and anything else you do may cause the bolt to stretch more and fail. To check mine they used a torque wrench with a dial indicator and checked to make sure they were at the initial 59#'s. How much torque is added with the 130 degree turn is unknown. Once the bolt has stretched even a few thousandths it's integrity will be compromised for any future use.

 

I did a little reading on using stretch bolts and the degree method to torque. Oversimplified version is that it's the most accurate way to torque-using the click method can be off as much as 35%. So the question remains why does tightening the U bolt reduce or eliminate the suspension vibration? Did GM not get them tight enough? Did they get them too tight and they stretched too much so that they are now loose and will fail someday? Is the U bolt defective? Is there a "seating" process for the leaves that lets them get looser?

 

My dealer is going to talk to GM but I think I already know the answer. Nothing will happen unless a future Service Bulletin covers the issue.

[camcamaro1991]

 

Here are the spacers/dampers sandwiched in-between the rear leafs, my 2013 did not have these, not sure about the early K2xx, please report back if you have them or not.

[ChevyRoofer]

 

Here are the spacers/dampers sandwiched in-between the rear leafs, my 2013 did not have these, not sure about the early K2xx, please report back if you have them or not.

 

 

Sub'd. I know there were old threads about using this clamp on the back springs to reduce vibration...Is this GM's fix?

 

Did you get this brand new from GM CamCamaro1991?