issue Transmissions Issues/Problems

Prokopchuk_9 · February 17, 2014

Same with my truck. One instance I was in the turning lane slowing down with brake slightly waiting for a car nine left lane to pass so I could pull into said lane, but, as the car passed I took my foot off the brake and hit the gas to get in the flow of traffic and the truck did nothing, I mean nothing. Like the truck was engulfed in a stupid confusion, it sat there while I pressed the gas pedal further and further getting pretty worried about the whole new set of cars getting bigger and bigger in my mirrors. I took my foot off gas and pushed back in and it finally roared forward spinning the tires like I was 16 all over again, only this time I was scared...

The transmission has acted up from time to time but a similar incident may have the potential to cause a wreck given the right circumstances.

Wasn't towing anything. Completely stock sierra 5.3 2wd 3:42 gears.

My 2011 Z71 5.3 did this. When it was time to downshift, it literally felt like the transmission just sat there, thought about what gear to go in, then applied power. It was really cumbersome. I hope this all gets remedied for 2015 *fingers crossed*

Power enrichment delay and a few other torque management tables can take the blame for that. GM's idea of tuning a transmission is really sloppy IMO. Just spend $300 on a tune call it a day...

Badass69 · February 17, 2014

My 09's 6L90E plus the rest of the 100 truck fleet never smartened up in stock form. Mine still shifted like it was programmed by a mental degenerate at 60000 miles so time did nothing. The adaptives take a little bit but by 1000 miles you are past where they do anything anymore.

Get the TCM tuned and it will shift closer to expectation.

Sent from the Great White North

pm26 · February 18, 2014

How old are these trucks people are having issues with? They are smart trucks, they learn. Give it a good 3-4k for the tranny to "learn" decent....just a thought

The trucks are only as smart as the people who designed them and programmed them. Given the strict marching orders to maximize the fuel economy at the expense of performance, your truck is "tuned" for maximum fuel economy, including odd transmission behavior under some conditions. Aftermarket tune appears to be the only way to fix this issue.

albertarbiter · February 22, 2014

hey everybody i am new here. i got a stock 2014 sierra SLT AT and i am wonder what temperature is everybody getting while on the highway for there transmissions. i am in canada is -15c/5f out side and i am getting temps around 65c/149f. on my old 2011 sierra 4.8L 4 speed i was getting around 32c/89.6f in the same cold weather. is that normal? and i am not towing yet only have 600kms on the truck so far

sgodfred · February 23, 2014

I guess my transmission is just dumb. 6900 miles and it still hasn't "learned" how to shift into second. Today it shifted so hard I thought someone hit me.

cmpcpro · February 23, 2014

I guess my transmission is just dumb. 6900 miles and it still hasn't "learned" how to shift into second. Today it shifted so hard I thought someone hit me.

Don't feel bad my trans rode the short bus too.. 3800 miles and every once in a while I'm still getting the searching while shifting where the rpms jump up for a second. Also with all sounds off I can hear the trans click occasionally.. can hear it coming from underneath

pm26 · February 24, 2014

Honestly, after reading all this, I am glad I have the old 4 speed auto in both my truck and my Impala. No problems so far, no harsh shifts, no annoying up and down shifts on every incline. I'll take a 2 MPG penalty any day over an erratically shifting 6 speed.

GM is definitely not the only company having issues with their new auto transmissions. Recently I read a lot of complaints about Infiniti 7 speed automatic. I have an Infiniti G 37 sedan with a 6 speed manual transmission. I decide when the shift, not some software.

Coy9901 · March 1, 2014

Ok, I'm glad others are having this issue also. My truck was three days old with less than 300 miles on it when I brought it back to the dealership with transmission issues. They had it in their shop for 21 days trying to guess the issue. I basically got an entirely new transmission they told me after all said and done. The issue, they told me was the torque converter.

To describe my issue: it felt as though my transmission would go into neutral at every stop. I would step on the gas when the light turned green the engine would rev until around 2K RPM's then jump into gear. Same issue in reverse.

I'm somewhat glad to see others are having close to the same issue.

pm26 · March 2, 2014

Ok, I'm glad others are having this issue also. My truck was three days old with less than 300 miles on it when I brought it back to the dealership with transmission issues. They had it in their shop for 21 days trying to guess the issue. I basically got an entirely new transmission they told me after all said and done. The issue, they told me was the torque converter. To describe my issue: it felt as though my transmission would go into neutral at every stop. I would step on the gas when the light turned green the engine would rev until around 2K RPM's then jump into gear. Same issue in reverse. I'm somewhat glad to see others are having close to the same issue.

New transmission at 300 miles. Says volumes about GM quality. At least they took care of the problem which is a big plus for your dealer.

OUSux · March 2, 2014

How old are these trucks people are having issues with? They are smart trucks, they learn. Give it a good 3-4k for the tranny to "learn" decent....just a thought

just rolled 8800 miles and still having this issue......

Ezekiel2517 · March 4, 2014

I had noticed this slightly, but after having my truck in twice for seat rail issues, I really noticed my loaners shift so much sooner. In my truck, I have to accelerate, then let off gas around 20 mph to get it to smoothly shift into second. Almost like my '82 F100 I had as a kid when the gears went bad. I have noticed more and more the hard "clunk" downshift into second gear from thirds as I decelerate. I am worried now reading that no-one is getting any releif with this issue. My loaners were so much smoother shifting than my truck. Any recent ideas on recourse? I have over 6k miles.

tchurch · March 8, 2014

I am having the same issue with my 2014 Sierra. Absolutely no help from dealer. Dealer says its normal for GMC truck. That's a shame. 4000 miles on the truck and like the truck other than the transmission clunk. From all of the comments already posted on the net regarding this issue you would think GM would want to take care of it??

BlackDenali6.2 · March 8, 2014

I had the EXACT SAME problem, but then I looked down and realized my TC was off and I laid 75' of twin blacks on the pavement. My bad.

Gmcclanks · March 11, 2014

My 2014 GMC sierra All Terrain is doing similar things with up shift where it clunks sometimes, feels transition fell out of truck and It shift rough as well. I have taken it in to the dealer twice now and even went on a ride with tech. The tech said something doesn't seem right however it's not consistent enough and that it will need to get worse before he can figure it out. That's great at 5000k miles I wish I didn't give up my Toyota for this.

juf · March 11, 2014

My transmission is hit or miss. Some days it's silky smooth and shifts early when you'd expect, and the next day it tries to climb a steep incline at a slow speed in 3rd gear at 1100 RPM and almost stalls. Seems hesitant to shift too often though. My dealer isn't any help, "hooks it up to their computer" and no codes so everything must be normal...