Jump to content

Auto 4wd noise?

pancepance
 Share

Recommended Posts

pancepance Enthusiast

pancepance

Posted
Posted

Wondering if someone can confirm of deny something for me please.
When using the "auto 4wd" position of the selector if there any noticeable rotational noise difference?

I am noticing that when in the auto position there is a noticeable noise happening. I would expect some noise change in the full 4wd position but in my Yukon when auto 4wd is selected there is no noticeable sound difference. I am well aware of how a 4wd system works and when to use and not use it. During the recent snows I was using the auto and realized that when its selected it sounds as though the transfer case is engaged and has a gear-gear noise. I haven't heard this on any of my other GM's with the auto option.
Before I go tot the dealer I figured I would see if everyone has a noticeable noise whenever using the auto mode?
Truck is a '14 gmc sierra.

Thanks

  • Replies 69
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

Popular Posts

BigBadSierra
BigBadSierra

Don't get confused between 4Auto and 4 hi and lo. 4Auto uses slip clutches to function so they will never bind up.  4 hi and 4 low can always bind up an click given the right conditions. I only use 4

txchevy4ever
txchevy4ever

Please post what you find out, and the repair order when they figure it out. Thanks!

Dmcortez
Dmcortez

I recently purchased a 2015 GMC Sierra SLT. I had a 4 inch pro-comp lift and 33's Toyo M/t's installed by a gm authorized shop before I picked up the truck from there dealer. Within 200 miles I notice

Spurshot Senior Enthusiast

Spurshot

Posted
Posted

Essentially no noticeable noise in my 2014 or any prior models I've had. Try 4 hi as we'll. shouldn't be any there either.

Brian S. Enthusiast

Brian S.

Posted
Posted

I didn't notice the noise, but with my 2014 Silverado 4.3l I noticed some vibration on acceleration between about 20-40 mph in Auto.

 

Now with my 2015 Sierra 5.3l I don't have the vibration.

 

With both of them I could tell when disengaging the Auto, felt like a little strain was relieved on the engine. I don't remember that with my 2002, 2006, or 2010 5.3s, but I am getting older. :(

timstruck Enthusiast

timstruck

Posted
Posted

I have experienced this as well with the recent snow. I can say that I heard and felt the noise/vibration in both 4a uto and 4 hi. I too am familiar with 4 wheel drive vehicles, and I can say that this is very similar to a 2000 ram 4x4 I had. once engaged you could feel the gears. I don't know the exact vocabulary, so forumsters, please don't roast me, but obviously the ram had a different 4 wheel drive set up with the solid front axle, etc.

 

I will also add that the vibration didn't sound harmful... you could just tell something else was engaged on the drive train.

Silverado-Hareek Senior Enthusiast

Silverado-Hareek

Posted
Posted

I have no noise with my 4 auto mechanically speaking. (I do have the high pitched electrical squeal discussed in another thread that has to do with the 4 wheel drive knob/circuitry). I have not used 4hi or 4 lo yet. I do remember on my 2007, 4auto was silent but 4hi had a sound as if something new was engaged mechanically (the front drive shaft obviously) but it wasn't a bad noise like a grinding or anything like that, just the noise of something else working. I expect to hear something similar in my 2014 when I use 4hi but so far, 4auto is silent....like I'm driving in 2hi.

BigBadSierra Senior Enthusiast

BigBadSierra

Posted
Posted

In auto the front transfer case is still engaged. The computer reduces and increases the torque to the wheels as needed.

 

This is why the fuel millage drops some in auto. At the minimum the transfer case is spinning.

 

I can tell by how my truck sounds if the auto is on vs the sound it makes in 2 hi.

pancepance Enthusiast

pancepance

Posted
  • Author
Posted

I am fairly familiar with 4x4 trucks having owned them for many years. This one has got me wondering though. Especially after I compared it to my '12 Yukon with a similar 2wd, auto, 4hi, 4lo selector.
Theres no noticeable difference between the 2wd and auto in the Yukon. on the same roads in same conditions.
The Sierra absolutely has a noticeable mechanical constant noise. I realize the transfer case would be engaged in some form or the hubs would be locked but in a situation where there would be no need for power to be applied to the front gears I would expect not to hear it as though it were in 4hi. When switched to 4hi it makes the same noise. I would expect a change in noise if using 4hi but the auto has me wondering.

It almost as though the "auto" part of it is not working and its just in 4hi. Something is definitely turning constantly and making noticeable sound when doing so. It doesn't go away from auto to 4hi. Only gone in 2wd.

Time to visit the dealer and play the "its supposed to sound that way" game. I looked on the lot today and see a very similar '14 for sale so at least I can have them demonstrate how it will happen in that truck I suppose.
Just seemed odd to be making that much noise even for 4hi.
Will update on findings as they progress.

Thanks for the comments

GMTEC2 Enthusiast

GMTEC2

Posted
Posted

I also have the noise as described. It's definitely a noticeable change from 2 to Auto and 4 hi

 

2014 GMC Sierra

Yamiryder Enthusiast

Yamiryder

Posted
Posted

Mine makes noise from the switch. It's a very high pitched noise when in AUTO or when engaging 4 hi. I took it to the dealer, they did a recall. Seemed to make it slightly better but the noise is still there. I've contacted GM as well. Seems that there isn't anything they can do about it. Pretty lame if you ask me. I shouldn't hear noise from my switch.

Isriam Enthusiast

Isriam

Posted
Posted

Mine makes noise from the switch. It's a very high pitched noise when in AUTO or when engaging 4 hi. I took it to the dealer, they did a recall. Seemed to make it slightly better but the noise is still there. I've contacted GM as well. Seems that there isn't anything they can do about it. Pretty lame if you ask me. I shouldn't hear noise from my switch.

 

hes not talking about the high pitched squeel from the switch. thats another issue. this is about transfer case noise. auto isnt really auto, its more like 4wd and why i refuse to use it.

pancepance Enthusiast

pancepance

Posted
  • Author
Posted

Yes, I get a noise during the switch from one position to another. My concern is a constant mechanical gear/gear type noise. Similar to a rear end as its starting to go. This noise will increase/decrease with speed and is only apparent out of 2wd.

I rode in a '14 Silverado today that had no noticeable noise when operating in auto or 4hi. Compared to mine its a night and day difference.
I also noticed today that when in auto if I come to a complete stop and reverse there is a clunk as a start in the other direction. Then if I stop and go the opposite direction it clunks again. Similar to the sound a bad U-joint can make when starting from a standstill. This is new and I hadn't noticed prior but it does it consistently each time. Just one time from standing start at regular pace. Not any type of power takeoff, just as if you were making a 3-point turn in a parking lot. Each time I change direction there's a clunk and then not again till I've come to a complete stop and restart motion.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.

  • Forum Statistics

    250.4k
    Total Topics
    2.7m
    Total Posts

  • Member Statistics

    342,759
    Total Members
    8,960
    Most Online
    DM22
    Newest Member
    DM22
    Joined

  • Who's Online   6 Members, 0 Anonymous, 1,554 Guests (See full list)

  • Latest Articles

  • Posts

    • KARNUT
      OCI, not when but why?

      By KARNUT · Posted

      As a matter of amusement I’ll leave this conversation with this. Do you beat the government average fuel estimate? Statistics are a guide to me. Not a rule. Someone once said I have to have the last word. If true and possible may be. I’ll blame that on working in a family business.
    • bluev8
      Intermittent no-code issues on 2022.5+ V8 trucks — what did the shop fail to capture?

      By bluev8 · Posted

      That is a fair point, and I agree that trying to log “everything in the truck” would be the wrong direction.   There are a lot of modules and a lot of traffic. If the product became a full-truck datalogger, the amount of data would get huge very quickly, and most owners would never use it.   I think the first useful version would need to be narrow: - powertrain-side event evidence - selected high-value parameters - communication / voltage / reset events - pre/post event window - short report first, raw log only as backup   One distinction I should make is between active OBD/PID polling and passive bus capture. If you are polling PIDs through OBD, then yes: the more parameters you request, the lower the effective sample rate becomes, and you are adding diagnostic traffic to a vehicle that is already busy running itself. With passive CAN capture, the recorder is not asking all the modules for data. It is listening to traffic that is already on the bus. So it does not consume vehicle bus bandwidth in the same way that a scan tool polling hundreds of PIDs would. But your point still applies in a different way.   Even if passive capture does not add bus traffic, the recorder still has limits: - processing rate - storage rate - timestamp accuracy - decoder workload - event filtering - report size - user attention span   So the answer cannot be “log everything and let the user figure it out.” The product would need to store enough raw evidence to be useful, but only decode, graph, and present the important parts around the event.   A practical report should probably show: - what triggered the capture - how much pre/post data was preserved - which selected parameters changed - how those values compared to baseline - whether the same pattern happened before - whether any voltage, reset, bus-off, lost-message, or communication fault occurred - selected graphs around the event - raw data only as supporting evidence   So I agree with you. More data is not automatically better. The real product is the reduction from raw data into a useful event report.
    • bluev8
      Intermittent no-code issues on 2022.5+ V8 trucks — what did the shop fail to capture?

      By bluev8 · Posted

      That makes sense, and I agree with most of that.   I think the product would need both: 1. a default powertrain template, so it is useful out of the box; 2. user-selected priority parameters, so the owner or shop can choose what they want to see first.   Different users are going to care about different things. One owner may care about oil pressure and voltage. Another may care about misfire trend, AFM/DFM behavior, or U-codes. A shop may want communication events and repeatability first. Your baseline point is probably the most important one. Raw data is not very useful unless the report can show what normal looked like for that vehicle under similar conditions.   The way I would think about it is: - start with a basic known-good baseline - learn normal behavior for that specific vehicle over time - allow the event to be overlaid against baseline - show whether the event was a one-time spike or a repeatable pattern - provide a simple severity level, but with clear limits on what that severity means   For example, early severity could be something like: - Info: event captured, no obvious abnormal pattern - Watch: value moved outside baseline, but not repeated - Warning: repeatable abnormal pattern under similar conditions - Critical: communication loss, voltage drop, bus-off, reset, or severe repeated event   I would not want the first version to say “replace this part.” That would be overclaiming unless there is repair-confirmed data behind it. It would be more honest to say “this pattern deserves inspection.”   On the OBD port question, I think OBD absolutely has a role. OBD is probably the right place for: - DTCs - freeze frame - VIN - calibration information - normal scan-tool parameters - Mode 6 / enhanced diagnostic data if available The reason I am still looking at an ECM-side recorder is that the failure may happen before anyone connects a scan tool. If the owner plugs in a scanner after the event, the pre-event evidence may already be gone unless the ECU happened to save it. So I do not see this as “OBD versus ECM-side.” I see it more like: - ECM-side recorder: always armed, rolling buffer, event evidence - OBD/DLC companion: DTCs, freeze frame, VIN, calibration, normal scan data - phone/cloud: status, notes, upload, report generation, notifications   I agree that phone connection and push notifications would be useful. I just would not want the phone or cloud connection to be required for capture. The recorder should save the event locally even if the phone is not connected. The phone should help with event marking, download, notes, upload, alerts, and report viewing.   For a default GM V8 event report, would this list make sense? - RPM - calculated load / MAP - throttle position - vehicle speed - gear / torque converter state if available - coolant temperature - oil pressure - oil temperature if available - battery voltage - commanded AFM/DFM state if available - actual AFM/DFM state if available - misfire counters / roughness by cylinder if available - fuel trims - relevant U-codes / communication events - bus-off / lost periodic message / module reset / voltage drop events Which of those would you remove, and what would you add?
    • Grumpy Bear
      OCI, not when but why?

      By Grumpy Bear · Posted

      I went to the county a few years back to dispute my property taxes. To do that I hired an appraiser and a lawyer. The County Assessor wished to argue that the homes in my neighborhood the appraiser used were all 'distressed properties" and not representative of the "Market Average".    My response was," Of the 50 homes in our subdivision 43 of them were "distressed properties" under bank foreclosure and as such "Distressed IS the market". Lawyer about choked on his coffee and handed the Assessor the 'receipts'.    I won that case on the evidence provided by the Lawyer and the Appraiser.    We have the same thing going on here. My statements were based on the GOVERNMENTS NATIONAL DATA and yours on local markets in areas of your interest. They are both correct....   Thing is, this divergence was based on NATIONAL and not on LOCAL. I think you even understand that. But like you said, we are both stubborn and hardheaded.    I do not see any advantage to disengagement.  But that said we can step back to compose ourselves. 
    • revmanii
      Looking at ordering a '26 WT because I want a std cab, std bed

      By revmanii · Posted

      Trust me I appreciate the comments and concerns. It's what I was looking for to help me evaluate the situation and what I want to do. I have decided to move forward with the BORA hubcentric slip on 3/8" (.375") with the extended lugs nuts. Fedex says they should be here Monday :). Meanwhile, the dealer got the remote start and Patriot spray in bed liner done over the last couple of days. Also, I installed an inline stop/start eliminator today. Starts back up in what whatever mode you shut it off in, so you don't have to hit the button every time you fire up.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...