AndrewD

I ran 35 12.5r18's w/ a RC 3.5 lift. It only touched the sway bar at full lock barely on the factory 2015 stock 18's. Now I swapped to a Cognito 4in w/ Fox coilovers etc. The same tires won't come close to clearing the UCAs. I got new wheels with +12mm backspacing to clear and now they rub like Hell on the fender lips. I guess I'm going to have to go back down to a 33x12.5r18, or maby the equivalent of a 34/11.5. I love the new lift (and there is no turning back now after the mods that were done). I won't cut up the fenders either, but i'm very disappointed my tires wouldn't fit w/ the new lift!

I run 35x12.5 R18's on my 15 gmc sierra 1500 z71 (stock wheels). I have a RC 3.5 lift kit and it only rubs the inner fender at full lock and it touches the upper arm at full lock. This kit has angled uppers though. I DO NOT recommend this kit though. I haven't put much for miles on it ( maby 15-20k) it has already settled and now rubs a bit more. I also run a RH grill guard and RC hidden mount 12k winch (synthetic line). I did however just purchase the https://cognitomotorsports.com/cognito-4-inch-performance-lift-kit-with-fox-ps-ifp-2-0-shocks-for-07-18-silverado-sierra-1500-2wd-4wd.html. can't wait to see the difference.

There was a TSB at the least if not a full recall on these antennas. I forget which years were affected. It's worth a look.

Depends on the brand you buy really. You absolutely get what you pay for!

Thanks. I'll look into it. From the start the original issue was the torque position steering sensor. In doing this process I've come to realize that it was possibly the harness P# 38021685 the whole time (which I replaced). I have my factory rack still and I'm half tempted to plug it up with the new harness and see what happens. In theory it will still be flashed to the truck. If I could justify the cost of a new J-pass box, I would have one in the Mail already!

It's showing co544.5a

Nope you didn't sorry. It's a 2015 sierra Z71. Has 93k miles. The sensor issue started started about a year ago slowly with a message here and there. Then it progressed to the point where it came on everytime I drove it. The the PS actually started to go out while driving. It would be back on after I parked it and started to drive again. Then it was basically just out all the time and would magically come back for a short time here and there when I had to drive it while searching for a rack.

Let me start buy saying GM is really crapping on people by not doing a recall on these racks. I started with a torque angle steering sensore issue. This sensor being (built into) the rack it was "eat it" and do the whole rack. This is when I found out it is IMPOSIBLE to purchase a new r&p for these trucks. IF you can get one it is a reman. (And for anyone who looks or has looked in places like parts geek etc. They have one listed as new from Detroit Axle. IT IS A REMAN! Ask me how I know.) This all being said there is a long list (about 15) of part numbers of racks that have been succeeded because they will not flash properly to the vehicle. The newest is not even available from Detroit yet. The shop that flashed mine first was able to flash everything BUT the torque angle sensor. I then purchased the short harness from GM that goes from that sensor to the motor side of the rack (it did look a little sketch from the get go). With the new harnes it now flashes, but the steering angle sensor is throwing a code. Steering works again but now the you can read the steering angle sensor through the rack but not through the PCM. I still have all the same service steering system warnings etc except the PS works now. I'm basically at $800 with this shop and they won't do anything else. They will only install a junkyard rack and flash it from here. Has anyone on here run into a similar issue with flashing a rack to their vehicle, or does anyone have any idea of what I should try next? Possible PCM issue?

Yes i found an article that explains why it is designed that way. It is almost semi-floating to keep;it from binding. I have looked at about 8 different models now from chevy to GMC, truckas and suv's. they all have a small amount of movement when parked and your steer side to side. You may in fact need new bushings but it would be more of a metal on metal if one has gone bad. Also there would be a slight misalignmentof the rack after a while i would think. I have changed My steering rack for a different reason and it's only the 4 bolts/bushings that hold it in place.Yes i found an article that explains why it;is designed that way. It is almost semi-floating to keep;it from binding. I have looked at about 8 different models now from chevy to GMC, truckas and suv's. they all have a small amount of movement when parked and your steer side to side. You may in fact need new bushings but it would be more of a metal on metal if one has gone bad. Also there would be a slight misalignmentof the rack after a while i would think. I have changed My steering rack for a different reason and it's only the 4 bolts/bushings that hold it in place. ( Maby find a new alignment shop)

A couple thoughts you could check. 1: Does your truck have the sliding rear window, or has the rear glass been replaced? 2: have you inspected the weather stripping on the door and window on that side? I had this similar issue with water intrusion on my last truck and found out it was due to lazy work when the shop replaces the back glass. They did not put the sealant on well enough and I would get a wet floor when it rained. The only way I finally found it was with a helper w/a hose and me sitting in the fruck watching/looking around to see where it finally came in.

Here is my 2015 Z71 (not the best pic). I'm running the RC 3.5" lift but I added 3" blocks to keep the rake. It has 35-12.5-18's on the stock wheels. I like the setup but I am currently looking into some coilovers. I have not been impressed with the lifted struts. They do not hold up if your running anything extra I.E a Grille Guard, winch. Mine has both and it has caused the springs to settle in the RC struts.

You really need to look into a full kit for the desired height that you want. If you have pieced part of it together already then you would only need to buy whats missing. I personally also have a 15 z71 w/3.5" lift struts, angled upper control arms, rear block and front diff spacers. I run 35x12.5x18's on the factory wheels. I am however going to swap to an adjustable coilover for the front to get 4". Plus the lifted struts are garbage IMHO. Mine settled and have a crap ride. I have a RC hidden mount 12k winch and a Ranch Hand too..

I went RC 2". Then I did the RC 3.5" on my 15 z71 because I wanted 35's. You definitely get what you pay for (I also had a friend who was a dealer so I got things at cost). I haven't put 50k on my truck in 6 years and it hasn't held up to mostly paved road driving. If you run a grille guard,bumper, or winch then definitely don't bother with a lifted strut (at least not RC). Mine have settled because I have a Ranch Hand grill guard and a Hidden mount 12k winch. Even w/out any added equipment I would go with a trusted coilover.

I've heard these arguments go back and forth all day. I do and will always run a Ranch Hand because they are proven to work. They have updates now for parking sensor compatibility, and even being just the grill guard IMO saved you from some airbag deployments. Idk if im the only one who looked at both these pictures more that once ut that car was hit hard. I'm a firefighter and have done extractions on vehicles. It's amazing sometimes what these bumpers and grill guards will take/protect you from. Not to mention the animals I personally have had just bounce off mine. Well worth the money. I'm just pissed that my wife's suburban couldn't get one due to the radar system up front (adaptive cruise etc). I will figure out a way to re l ocate it though where it's still functional. Kinda like when they told me that the Ranch Hand grill guard and the RC hidden winch mount couldn't work together. They are both mounted properly on my truck...

Honestly I'm baffled that gm would put out a "Z71" with 3.08 gears. Mine is a 2015 Z71 w/the G80 rear end. It came w/3.42's and I run 35'12.5 18's on a 3.5" lift and haven't had any issues. I don't tow a lot but when I do it never has an issue.

UPDATE: I have Found after A LOT more research, and upon inspection of my own 2020 suburban and a couple trucks like my own that these racks are supposed to move. By design GM made them a (floating) type system to lessen the burden on the internals of the piston/cylinder itself. Contrary to my previous experience if it does not move then it is binding (most likely from frame or mount damage) which will cause undue wear and premature failure of the rack. Worst part of all this is that my original issue, my PS intermittently going out (steering wheel torque sensor) has no repair option. You are forced to buy a new R&P to replace the integrated (faulty) sensor.

I have a 2015 sierra z71 w/82k on it. Only major issue is the A/C condenser, an electric steering gremlin and and exhaust manifold gasket leak. It has a 3.5in lift with 35's a RH grill guard and a RC hidden mount 12k winch, and it gets used like a truck. Thanks to some wonderful idiots it has had some new fenders in the front and a bumper at the body shop at different times. I have a 2020 suburban premier RST w/the same 5.3L and that has 86k on it. Only issue w/that was the water pump went under warranty, but it seemed like it was more a bad part then a common issue.

Yup everything is tight. I guess the bushing are just worn out.. It does have over sized tires with a Ranch Hand Grille Guard, and a RC hidden 12k winch. Maby the extra weight w/the tires has helped wear out the bushings early.

It is the whole rack. You can see it visibly move side to side w/ steering wheel movement. That was my question, does this (under normal operation) have movement? Or are my bushings just so worn that they are about to be all gone? Ball joints are new, inner tie rods about a year old. Truck has a 3.5 in lift w/35's (35's are only about 2 yrs old) but I only have 80k on it too. It's a 2015 and had 285/75's most of those miles untill the 35's. Like I mentioned there is no noise I just noticed the movement while looking into the EPS issue I am having.

What is the normal amout of play (side to side) for the rack on a 2015 sierra? My 2015 z71 is having steering issues. I'm getting the service steering message and periodic loss of power steering. A diagnostic scan at GM said that their was an issue w/the steering torque sensor. While looking into that I noticed that there is about an inch of play side to side in the rack when you move the steering wheel back and forth. I do not have any noise/clunk indicative of broken bushings, just wondering what others with this year model truck have noticed w/normal rack play/movement.