2016 Silverado 2500HD Steering woes

[Mike Payne]

I have a 2017 Denali 3500HD with "loose" steering.  I don't usually give my resume' but I think it is relative to this subject.  For 12 years I was a professional test driver at a major competitor to GM.  I worked in the suspension development group at a proving ground testing and tuning shocks, spring rates, stabilizer bars, tires, etc.  My job was to dial in just the right amount of comfort vs handling vs steering response and feel.  Why is this important?  Because I am 100% confident I know what is causing my "loose" steering.  The problem is the digital steering assist tuning.   Although there is a documented issue with some steering gear boxes,  the "loose" steering in my vehicle is not from any mechanical problems with the gear box.  Please understand that I did not say no one has a gear box problem.  I am simple saying that GM has more than 1 issue due to poor steering feel.  

 

The problem with my truck has nothing to do with anything being "loose".  Here is the proof.  At all speeds below 45 mph the steering feels fine.  At speeds above 75 mph the steering feels fine.  If something was loose or wrong with my gear box or other mechanical steering component the problem would not magically go away below 45 mph and above 75mph.  In fact, with almost any kind on mechanical "loose" steering component the problem would be perceived as worse with most increases in speed.  

 

For folks with "loose" steering try this.  Pick a long straight level road.  Drive straight at 40 mph with the steering wheel straight.  Concentrate on the amount of effort (torque) it takes to turn the wheel 1 degree, 2 degrees, 3 degrees etc up to 10 degrees.  These are small movements of the wheel but you feel immediate effort required to turn the wheel these small amounts at speeds below 45 mph.  At 1 and 2 degrees of steering wheel movement there is effort but little to no vehicle response or yaw.  This effort is a "feedback" (although artificial and in the suspension tuning world effort is not necessarily feedback but for the sack of keeping it simple let's just go with that) to the driver about what is happening to the steering system and vehicle.  Now try this same procedure at 45, 50, 55, 60, 65, 70, 75 mph. Does the effort required to move the steering wheel these small amounts start to increase at 74, 75, 76, 77 mph?  If so, you have a poorly tuned digital assist system.   In my vehicle the worst speeds are 60-70 mph.  At these speed the initial 0-5 degrees of steering wheel movement require almost zero effort.  The digital steering is "over boosting" the required assist needed.  At speeds above 75 mph, my vehicle "magically" fixes itself and the effort required to move the steering wheel increases dramatically.  

 

I have read through all 39 pages of posts.  Some folks have described the exact problem I have.  "Loose steering" between 45-75mph.  Another fact is many have complained that their steering is no better after GM replaced multiple steering components including the gear box.  GM needs to assign an engineer to retune the digital assist.  I volunteer to help.  I just need access to the ability to change the power steering assist levels through the digital steering.  So GM if your reading this just look me up and I will help.  

 

I hope this helps others to identify their real steering problems.  I also hope GM fixes this with a simply retune of the digital assist parameters.  

 

Mike P.

[stadt11]

Hey Mike,

 

Great info.  My issue was only observed b/w 60-70 until it was fixed.  How would you go about reprogramming this, can it be corrected via Custom Tune or more specific physical component?

 

My issue hasn't come back (yet), I'm at 37K.

 

Andy

[i82much]

could one theoretically just turn off or remove the digital assist to test this?  

Edited January 18, 2019 by i82much

[gearheadesw]

In for what Mike P has in store for us.....

[trpower]

My was the lash adjustment backing out. It was loose from very slow spee2ds to scary at high speed. There also was a computer flash done after the repair. Mine has the loctite at the threads,nut. Have over 25,000 miles on it and still tight. Seems like more than one issue going on with this steering. 

[Mike Payne]

I did contact PPEI to see if they offered a custom program for the module that controls the power steering digital system.  They said no.  I'm sure if many folks were asking for this custom feature PPEI or someone else would offer it.   

[randemgun]

Here is another case study! 2016 Silverado 3500 hd built in Flint Michigan  plant.  Roughly 18k miles very loose steering. Dealer tightens lash bolt and lock tight. 27k loose again, dealer says first guy didn't do it right, re tighten and lock tight. 35k loose again. This time I looked underside and see small fluid leak from steering box. Dealer replaced steering box today, so far so good. Will edit post if it gets loose again.

[Dirtbiker]

So I just got my truck back. At 134,000 km the nut backed off and my steering got loose. $400.00 to lock tight a bolt seems a little steep.....

But steering is back to normal again. Hope it stays tight from now on.

[20SierraL8T24]

My nut backed off @ around 18k & I lost fluid. I had the TSB performed & have 52k on it now. So far so good but its always in the back of my mind

[avalonandl]

This is why I a glad I have the 2015 HD.

[GTBensley]

Thinking I may have a problem with mine. 2016 2500hd with 37K. I have a slight clunk in the front end over small bumps and the steering has a bit of play. Shook the front end down and it seems to be play in the box or maybe the pitman arm. Need to look this TSB up and see how much of a pain it is for me to do it. 

[modoutlaw]

Well mine has come loose again.  Way worse than the first time.  A 1/4 turn of slop now.  This time it was instant.  I was on the interstate running 75mph and steering just went loose.  Scared the hell outta me.  Had to drive 40mph so i could keep it in my lane all the way home.  Needless to say, but I am beyond pissed that the dealership wont touch it.  Even though they are supposed to cover the steering box with an amended warranty.  This crap needs to be a recall.  

I got under the truck and took a look, the lash adjuster has backed out about 3/16 of an inch.  Fluid is pouring out everywhere.   

I am sick and tired of this. 

[gearheadesw]

Bump.

So, truck is wandering on the road going straight, going to make and appointment for TSB  PIT5501F. I have some modifications to the front end, cranked bars, shocks, big tie rods, upper control arms, does this raise red flags at the dealership? Will they just adjust the lash, Loctite, and go, if the front end is nice and tight?, alignment is good.

[gearheadesw]

And, the TSB PIT5501f, has been superseded by another, that specifically states to omit the model year 2017, and would have only covered up to 36K miles anyhow. Nice.

[gearheadesw]

Truck is at the dealership, they are doing the pitman arm, idler arm, and center link, under warranty, excellent.