George J. Klinkhardt III

The springs were defective and allowing the two to shift at the ends....U Bolts were tight! (torque at 180 ft lbs+)! As I stated, they wrapped a hose clamp around the front and rear on both sides and this stopped the movement...of course I didn't want to leave hose clamps on a 40K truck...so tech ordered new springs (complete with the heavy duty leaf) and when they were installed....Stopped all the shifting which was minute, but enough to make a noise....Fixed the problem and no hose clamps to embarrase me or GM!!

See my post under shakes and vibrations....dated 8-16-14....Replaced my rear springs...also cured my problem. (page 176)

I posted on this forum back in Jan and Feb....a final report now...Truck 2014 GMC Double Cab Sierra z71 2WD with 18" tires..built 7-13 and got possession 9-13..After 8 trips to my selling dealer (160 miles each roundtrip) I finally convinced them the vibration/shake was in the side to side movement in the oem Goodyears (btw, 4 months later the dealership was STILL trying to get reimbursed by GM for the tires THEY purchased at their expense)...installed new Bridgestones and cured 98% of that problem..then I had the clunking noise in the differential noticeable at slow speeds during a turn or crossing a driveway entrance, etc. Well, contacted another dealer namely Glen Sain Motors, Kennett, MO (located about 16 miles away) about the rear end noise originally in April 2014 and even though I didn't buy the truck from them, they took a genuine interest in my problem and yesterday finally time after time fought GM tech and went to bat for me and the truck is FIXED!! Events and the cure: replaced Rancho shocks, no cure. Check run out on the ring and pinion and was .004 exceeding the .004 allowed (mine was .008 out) so GM instructed to replace the complete differential and I do mean complete (brake calipers, axles and all) AND a new driveshaft........Still no cure! Two mechanics of the dealership actually layed on their stomachs in the bed while another mechanic drove the truck slowly in the dealership parking lot and PRONTO discovered the noise was coming from the spring leafs shifting side to side and causing the noise!! They home engineered and put heavy Hose Clamps (2 on each spring) and PRONTO again - cured the noise!!!! After much discussion with the GM tech, they finally convinced him to replace both faulty rear spring assemblies and I picked up the truck yesterday afternoon and ALL is fixed..It was a spring problem ALL along and thru some ingenious "shade tree" engineering by the mechanics...they found the problem!! All the replacing of expensive parts (namely the complete differential and new driveshaft) could have been eliminated if GM tech had've LISTENED to these "lowly" mechanics all along!!!!!! Remember KISS - keep it simple stupid!!! Bottom line: I commend this dealership (especially the service manager) for fighting for me and having a strong determination to fix my truck! Remember this does take time (if you can find a dealership with their determination) as they kept my truck almost three weeks (which was fine with me, because I JUST WANTED IT FIXED!! And a lot of the time was spent waiting on parts because nothing could be ordered until an okay was received by the high and mighty GM tech guys! Maybe the GM tech and engineering department will learn from this experience and put out a bulletin nationwide so that the next clunking noise complaint that comes in will be fixed by simply replacing the faulty rear springs!!!!!! BTW, the truck now has 13,250 miles and we've been fighting this problem since about 1,200 miles! I really like this truck and I am so happy to FINALLY have all the "bugs" worked out so I can completely enjoy it... BUT, I'm still convinced that without the help of this dealership's determination, it would remain NOT fixed and I am totally disappointed in GM seemingly continually turning their backs to problems that exist in these new vehicles!!!! I have found no where that GM has even admitted that all those oem Goodyear 18" that were originally out there were FAULTY!! And they had to know because mysteriously they quit shipping new trucks with THESE tires; now Continental, Bridgestone or Generals!!) That's very distressing to a LONG time loyal GM customer. (and by the way, ALL new parts came in with "Made in Mexico" stickers!!! duh) Hope this helps someone out there and with that I will close.............

The key here is "uphill"..my friend has a '14 Silverado Z71 4WD 5.3) that is in the shop now for bad vibration under cruise going up hill at 35-45MPH....Serv Mgr drove the truck and noticed the truck was staying in the V4 mode even going uphill...the SM called GM and they advised him there were no updates to "adjust" the V4-V8 mode, etc, etc, etc. as usual.....Check YOUR truck on your particular hill and notice the dash...if it's staying in V4 (light will be green) even under slight acceleration - - this could very well be your problem also. Even the old cars would raise the devil if you pulled 4 plug wires and tried to go up a hill.

I mean that there DEFINITELY is a problem and experienced by many who are NOT members of this forum....if you don't by that...ask several (which means more than one!) service managers how many they've had reported and you'll find out that it's many more than the 100 members on this forum "as you say". BTW, if you don't like my comments...why do you take the time to read them....Real simple - if you don't like my posts or what the "100" other members post - - DON'T READ THEM!! If you haven't had any of the problems shown on this forum with your 2014 truck, you are fortunate, and why the hell are you on here??!!??

See my other post under shake/vibration thread..page 39...The new shocks did not stop the thunking..on further investigation by shaking the bed harshly SIDE TO SIDE...the noise is coming from the center chunk of the differential....I checked 2 more '14s and 2 '13s (one of which my son drives) and no movement or slop at the hubs and therefore no noise!...Taking mine back in Feb. 4th and they are gonna look inside the differential (rear end) and see what the problem is....I will post what we find and if it cures the thunking-popping noise only when making turns....the Svc Mgr and I both agree that this may be also causing or adding to the vibration issue at 70-75 also...As posted before the change from GY's to Bridgestone Duelers took about 95% of my vibration out of my truck... The GM gurus continue (as they have since August 2013!!) to ignore these nationwide problems!! And I'll say again: I love this truck otherwise...

I got a call yesterday from a local dealer in which I am friends with the service manager..said had another '14 truck (Z71 4WD) with the vibration issue...with Goodyear 20's....upon driving the truck, he noticed the vibration worst at 30-50 mph and also noticed while gradually accelerating...truck STAYED in V4 mode! Said called GM and they had no adjustments that could be made to correct this problem!! (Forunately, I have not had this certain problem with mine)...so he's gonna continue to research and THEN will probably be faced with changing out the tires to another brand because along with problem above....the truck also has the common 70-75 vibration! I've also discovered I have the thunking noise in the rear...he replaced the Ranch shocks and no help...I noticed with a hard side-to-side movement on the bed....the noise is coming from axle slack or hub slack..I looked at 2 more '14's and no noise...looked at two '13's (one of which my son drives) and no noise... So I'm taking it back in Tuesday Feb. 4th and they are gonna look inside the differential to see what's loose....I will post what we find and if it was corrected.... BTW, as previously posted, the replacement of my GY's with Bridgestone Duelers eliminated about 95% of my vibration issue...the GY's were NOT out of round and road force balanced well within the guidelines -- rather not true when on the balancer with a side-to-side movement or wobble..... The more I think about this and the Ser Mgr agrees....some of this may be due to something wrong inside the differential...(mine has 3.42's) The saga continues and GM gurus still are HIDING from this nationwide problem!!!! I still love the truck otherwise!!

Got under mine today and sprayed the rear spring shackles with WD-40 and stopped the noise...somethimes it is much easier to "do it yourself" than screw with the warranty people.. Revised***** Took mine in for the recall update and service dept determined that the rear Rancho shocks need to be replaced....will be installed 1-28-14 and hopefully cures the popping noise......if not I will post; if cured I'll be happy!

Why in the world should a customer have to spend $60 on a brand new truck that is under bumper to bumper warranty????? It's again an example of GM dodging the issue...Any expense should be paid by GM to keep the loyal customer happy!!

Same here with me as previously reported..new Bridgestones cured about 95% but still has slight vibration/shake 70-75 mph....think I'll leave it alone....BUT I still wish GM would admit they have a problem and give us loyal customers a heads up on what their plan of attack is gonna be...NOT KEEP IGNORING the problem and leaving up to us to find a solution.....This just ain't right!!! Also, if anyone hears of a Goodyear recall on these tires (which is expected by my local large Goodyear distributor) please let us all know.............Thanks

I don't have a rip for you my friend, but I disagree with you and your statement above that it takes time to find out what's wrong and they are busy and have other customers.....I think you are talking about the dealers - - I'm talking about the GM tech gurus in Detroit! They are the ones that have been dodging this crisis with a lot of loyal customers (this is my 13th GM pickup!)...to fix the shake/vibration problem, they have to FIRST admit they have a problem and accept that. Then let their guru engineering minds decide what the heck is wrong to be causing this recurring problem all over the country....I'll again admit that the tire change from Badyears to Bridgestone (which was done by my dealer at his expense to keep me happy) cured about 95% of my problem - - - BUT there are still many on this forum that are running into dead ends and GM headquarters don't seem to give a hoot!

Just got my fire risk recall done this morning...also had the Rancho rear shocks checked because of noise and leaking...ordered a new set to be replaced under warranty next week...and BTW, asked the service manager if they had seen many complaints on the shake/vibration issue and of course he said - NONE! This is a fairly large dealership that sells lots of Sierras/Siverados... And also I guess the GM gurus are still dodging this issue and their responsibility to us loyal customers.........FIND US A FIX ASAP IF YOU GIVE A SH** ABOUT YOUR CUSTOMERS!!

Got under mine today and sprayed the rear spring shackles with WD-40 and stopped the noise...somethimes it is much easier to "do it yourself" than screw with the warranty people..

If they tell you they are gonna check hub runout and/or rotate the driveshaft 1/2 turn - - be aware both of these "GM" recommendations were performed on my '14 Sierra DC and did not help! The installation of new Bridgestones took about 95% of the vibration at 70-75 mph away....

We appreciate your reply BUT the dealers are waiting on GM to give THEM direction on this persistent problem....Can you not have the GM tech/engineers read this forum topic and surely they are smart enough to see they have a problem....Please do what you can to get the GM gurus involved and then they can inform the DEALERS about the possible fix! It seems that one arm of GM doesn't know what the other arm is doing and we keep running into a wall of "see your dealer, register a complaint, etc!" REMEMBER IT IS NOT THE LOYAL CUSTOMER'S RESPONSIBLITY TO FIGURE OUT A FIX - - IT IS GM'S RESPONSIBILITY TO ACT IN A PROFESSIONAL MANNER AND GET THIS RESOLVED AND SOON!!!!!!!!!!!!!!