Coming back. Maybe! I have a few questions

scottmoyer · April 8, 2019

Hey all. I have a few questions regarding the potential purchase of a 2018 GMC Sierra SLT.

Previously, I had a 2006 Silverado Z71 that I loved. I bought the truck new in 2005 and owned it for 12 years and 160k miles. In 2017, I got a new job that required me to drive 75 miles each way, so I decided to replace the truck with a car. Two months into the job, and the position was eliminated, so I owned a new car, but didn't have anywhere to go. I wish I kept the truck because the car was a lemon, Ford bought it back and treated me well, so I decided to replace the car with an F150. I decided on that because the Chevy/GMC trucks don't have back seat vents, are still plagued with the frame shake (my '06 had it with certain tires) and I heard about transmission issues on the GM brands. So, I bought a 2018 F150 XLT fully loaded. Guess what? It's a lemon too. I just finished the lemon law process after Ford is refusing to fix my issues. It also is trans related. The thing hesitates, can't find the right gear, slams into gear, and I have multiple cylinders misfiring. All of this was deemed "normal" by Ford, but the lemon law arbitrator thought it was a flawed design and awarded me a lemon law win.

So, I'm looking at coming back to GM and dealing with the frame shake (which I think is related to the type of tire on the truck) and the lack of rear seat vents. But, I don't want to go through this hassle with the trans on the GM side. Has it been determined what the issue was that plagued many? Was it only on 5.3L equipped vehicles? 6 or 8 speed? How prevalent are the issues with the GM trucks? It seems that many here are filing lemon law also.

What should I look for, and stay away from when buying this new truck? There are so many people complaining about the 5.0L/10 speed issues on the F150 side that any new buyer reading their forums might think to stay away. I didn't, because 2018 was the first year for this combo and it seems to be a bad combo.

Edited April 8, 2019 by scottmoyer

TXGREEK · April 8, 2019

Hey all. I have a few questions regarding the potential purchase of a 2018 GMC Sierra SLT.

Previously, I had a 2006 Silverado Z71 that I loved. I bought the truck new in 2005 and owned it for 12 years and 160k miles. In 2017, I got a new job that required me to drive 75 miles each way, so I decided to replace the truck with a car. Two months into the job, and the position was eliminated, so I owned a new car, but didn't have anywhere to go. I wish I kept the truck because the car was a lemon, Ford bought it back and treated me well, so I decided to replace the car with an F150. I decided on that because the Chevy/GMC trucks don't have back seat vents, are still plagued with the frame shake (my '06 had it with certain tires) and I heard about transmission issues on the GM brands. So, I bought a 2018 F150 XLT fully loaded. Guess what? It's a lemon too. I just finished the lemon law process after Ford is refusing to fix my issues. It also is trans related. The thing hesitates, can't find the right gear, slams into gear, and I have multiple cylinders misfiring. All of this was deemed "normal" by Ford, but the lemon law arbitrator thought it was a flawed design and awarded me a lemon law win.

So, I'm looking at coming back to GM and dealing with the frame shake (which I think is related to the type of tire on the truck) and the lack of rear seat vents. But, I don't want to go through this hassle with the trans on the GM side. Has it been determined what the issue was that plagued many? Was it only on 5.3L equipped vehicles? ^ or 8 speed? How prevalent are the issues with the GM trucks? It seems that many here are filing lemon law also.

What should I look for, and stay away from when buying this new truck? There are so many people complaining about the 5.0L/10 speed issues on the F150 side that any new buyer reading their forums might think to stay away. I didn't, because 2018 was the first year for this combo and it seems to be a bad combo.

I’ve got a 2018 Z71 SLT 4X4, Premium Package 6.2 and absolutely love mine. Zero complaints, and as a matter of fact I’ve already put $11k into the truck customizing it and with 16k miles on it there’s zero issues. If available, I’d look to find a 6.2 although it only takes Premium Fuel

Sent from above

Mike GMC · April 8, 2019

TEST DRIVE IT! Not just around the block, but on the highway and all the type of driving you usually do. If it shakes or shifts funny, walk away. 6 speed trans seems to have less issues. Otherwise if you like it, buy it.

miker2702 · April 8, 2019

5 hours ago, Mike GMC said:

TEST DRIVE IT! Not just around the block, but on the highway and all the type of driving you usually do. If it shakes or shifts funny, walk away. 6 speed trans seems to have less issues. Otherwise if you like it, buy it.

i would drive it a few hundred miles at various speeds on highway to make sure no vibrations.

gm will tell you the same its normal......I would drive every one on the lot to be sure I got a smooth one....

2500hd I traded was smoother than the 1500.....except when you hit a bump....my son has 30k saved

for a new truck im telling him look elsewhere.....if gm will not stand behind what they sell.

HeySkippyDog · April 8, 2019

The rear seat has floor vents.... [emoji2369]

It'll keep your piggies chilled.

Sent from my SAMSUNG-SM-J727A using Tapatalk

dieselfan1 · April 8, 2019

4 hours ago, miker2702 said:

i would drive it a few hundred miles at various speeds on highway to make sure no vibrations.

gm will tell you the same its normal......I would drive every one on the lot to be sure I got a smooth one....

2500hd I traded was smoother than the 1500.....except when you hit a bump....my son has 30k saved

for a new truck im telling him look elsewhere.....if gm will not stand behind what they sell.

Good luck finding a dealer that allows a few hundred mile test drive.

Find one that gives a full refund within 500 miles if its a vibrater

Edited April 8, 2019 by dieselfan1

scottmoyer · April 8, 2019

My concern is how prevalent the issue really is. The F150 that I'm lemon lawing now has similar trans issues and Ford has used the exact same wording that I'm seeing GM use to those with issues. But, with the Ford side, they sold over 800k F150s in 2017 and 1 million in 2018. If the forum shows only 1% of people complaining about this type of stuff, then we have only 8k trucks with this issue. That leave 792k people either not complaining, or not experiencing issues.

Every 2018 F150 I've driven experienced the same problems, so I believe the issue is much larger than what's seen in the forums and online. I think it all has to do with the adaptive learning of the new 10 speed trans. It sounds like GM might have the same issues because I've been reading where TSBs have resolved some of the drivability issues for some, but not all. I also found the frame shake could be related to the drive shaft being either off balance or not true. I'm hopeful that some of the complaints I heard about have a fix and/or not as prevalent.

amxguy1970 · April 8, 2019

The rear vents are a non-issue, more cool air comes out of the front vents than what trickles out and comes out warmer in the rear. I live in Texas, no issues with cooling the cabs or rear passengers.

There is no "frame" shake. Wasn't there on the GMT 400, GMT 900 or T1's. A very small group of people have experienced a vibration (which vibrations are driveline related) but many get it fixed with a road force balance or new tires, others it can be drive shafts or axles. It is a mechanical item assembled with thousands of pieces and hundreds of peoples, things will go wrong across all manufacturers (some more than others, GM just seems to be better and have less issues). What you read on the forums even though many come to complain is still much less than what is actually out there. A truck that shakes might account for 1% of the total trucks produced. Just do a thorough test drive (not 150 miles that is absurd) and see, chances are it will be fine.

BTW, transmissions are becoming more and more wonky across all manufacturers, with all the computer controls and parameters that are tracked it is hard to identify every single possible scenario and never have a hard shift or confused gear change. The more gears they add and more sensors they have to read the higher the chances a particular scenario is overlooked. The trucks are great, chances are very high you won't have a problem. Just buy one, be happy and see.

Tyler

mookdoc6 · April 8, 2019

Definitely stick with the FERD it's obviously the way to go! LOL

aseibel · April 8, 2019

58 minutes ago, amxguy1970 said:

What you read on the forums even though many come to complain is still much less than what is actually out there. A truck that shakes might account for 1% of the total trucks produced. Just do a thorough test drive (not 150 miles that is absurd) and see, chances are it will be fine.

^ This.

My truck is as smooth as silk as fast I need to drive it (which is only around 75). Take it up to whatever freeway speed you travel. Just a couple miles should suffice. If it doesn't shake, then you are good. You shouldn't read forums about problems you don't have, only makes you paranoid.

Likarok · April 8, 2019

Come on back Grasshopper!

xax · April 8, 2019

My 2017 sometimes vibrates rolling down the highway, trans clunks into gears when coming to a stop/taking off. I much preferred how my 2011 drove compared to this one, as crazy as that may seem.

SILVER SLED · April 8, 2019

I hate to jinx it by my 18 8 speed with a 6.2 drives awesome. It shifts/drives a lot better than my 15 6 speed.

scottmoyer · April 8, 2019

So what I'm hearing is the frame shake (that doesn't exist) will happen from the very beginning? Here's what I had. My '06 drove like a dream with the Factory Firestones on it. I upgraded to the BFG AT KO in 285 series and had really bad bouncing in the rear. Discount Tire did all they could with road force balancing, etc and they couldn't resolve it, so they replaced all 4 tires with another set. Same issue. Michelin (owns BFG) stepped up and replaced the tires again, but with the Michelin replaced them with the LTX AT2 (E rated) and I got close to 80k miles out of them with no bounce. I then replaced those with the BFG AT KO2 (E rated) and they drove beautiful for about 30k miles. When I went to replace them, I thought it'd be better to have D rated instead of the extra weight E rated, in hopes of improving my mileage and possibly changing my ride quality. Well, the rear end bounce was back. That made me think the extra rotational mass of the E rated tires might have offset that bounce and the lighter D rated tires allowed for the frequency issue that GM referred to as frame beaming or "frame shake"

Does any of that make sense? My experience with the shake did not present itself until the tires were changed. It went away and then came back with the next set of tires.

I would be really happy to get a new GMC and not have to have this concern. Now, I'm hopeful that the trans/torque converter issue is something that CAN be noticed on a test drive. I keep buying cars/trucks and start having issues after I sign the papers.

Cpl_Punishment · April 8, 2019

From what I've heard, the 6 speed is less likely to have issues than the 8 speed but, if you're set on an SLT, I think you're limited to the 8 speed. Not that the 8 speed is bad. Just had more problems reported than the 6 speed.

As others have said, get the truck out on the highway during the test drive and get it up to the highest speed you're ever likely to drive it at if you can (legally and safely, obviously).