issue Transmissions Issues/Problems

Haus_Z71 · November 20, 2015

Alright, another issue thread I get to be a part of.

I'm going to start with projectsummit's recommendation on the u-bolts, but I feel like something needs to be done about the electronic side of shifting.

My main complaint:

- Has a hard time finding a gear in any type of variable speed situation

- Mainly in stop and go traffic, when letting of throttle, then having to apply throttle to speed up, it hesitate then jolts into gear

- Once when having to take a left across oncoming traffic, it hesitated so much that I was stuck for 1-2 seconds in the incoming lane. Then it slammed into gear and limped forward.

I guess my next step is to take it in to the dealer,, but what can I expect?

nadrojcote · November 20, 2015

If you haven't had the transfer case recall done yet I'd recommend that too. Its helped some out with shifting. Mine seems to shift nice now. Not sure its from the recall or not. I still get a clank sometimes from 1-2 or 2-1 usually only the first shift after its been parked for a while.

mjj · November 20, 2015

If you haven't had the transfer case recall done yet I'd recommend that too. Its helped some out with shifting. Mine seems to shift nice now. Not sure its from the recall or not. I still get a clank sometimes from 1-2 or 2-1 usually only the first shift after its been parked for a while.

I agree. Not sure what else they slipped into that transfer case update but it definitely seemed to shift better afterwards. I took care of my sloppy shifting issues long ago with a tune but when I go back to stock for the free oil changes I notice the difference in shifting. After that transfer case update while still stock it felt like a nice improvement. Does anyone know if the transfer case programing lives within the TCM that this would make sense or are we thinking GM just made some software changes to both and kinda just slipped it in under the one recall?

TJay74 · November 20, 2015

No, the TCCM module is separate from the TCM module. The TCM is inside of the transmission.

Newell33 · November 20, 2015

I ran my first full tank of E85 recently, and noticed that the transmission shifted more poorly like it used to. Before the recall I did notice that when running E85, the shifting seemed worse, and the truck would accelerate in what I'd call small little bursts or stages. I'm guessing there are a different set of tables for E85, including the transmission. I'm going to try to go back to regular fuel to see if I can get back to the improved shifting I experienced with the recall.

HondaHawkGT · November 20, 2015

I ran my first full tank of E85 recently, and noticed that the transmission shifted more poorly like it used to. Before the recall I did notice that when running E85, the shifting seemed worse, and the truck would accelerate in what I'd call small little bursts or stages. I'm guessing there are a different set of tables for E85, including the transmission. I'm going to try to go back to regular fuel to see if I can get back to the improved shifting I experienced with the recall.

The engine and transmission control modules are designed to pass data back and forth. The transmission monitors the engine's performance and makes adjustments based on what it sees. It might improve with time but I've always thought that the E85 near me was inconsistent. Probably doesn't help that the stuff sits a lot lately with gas being so cheap.

andyhaug · November 20, 2015

I think the problem is this communication. What happens when the TCM doesn't get the data in time from the PCM/ECM? I think that would explain why it is so random as to when my truck does something stupid.

pm26 · November 22, 2015

Alright, another issue thread I get to be a part of.

I'm going to start with projectsummit's recommendation on the u-bolts, but I feel like something needs to be done about the electronic side of shifting.

My main complaint:

- Has a hard time finding a gear in any type of variable speed situation

- Mainly in stop and go traffic, when letting of throttle, then having to apply throttle to speed up, it hesitate then jolts into gear

- Once when having to take a left across oncoming traffic, it hesitated so much that I was stuck for 1-2 seconds in the incoming lane. Then it slammed into gear and limped forward.

I guess my next step is to take it in to the dealer,, but what can I expect?

NORMAL!

ToesonTheNose · November 22, 2015

Alright, another issue thread I get to be a part of.

I'm going to start with projectsummit's recommendation on the u-bolts, but I feel like something needs to be done about the electronic side of shifting.

My main complaint:

- Has a hard time finding a gear in any type of variable speed situation

- Mainly in stop and go traffic, when letting of throttle, then having to apply throttle to speed up, it hesitate then jolts into gear

- Once when having to take a left across oncoming traffic, it hesitated so much that I was stuck for 1-2 seconds in the incoming lane. Then it slammed into gear and limped forward.

I guess my next step is to take it in to the dealer,, but what can I expect?

yep same with me stop and go is the worst it cannot find a gear to save its damn life

Jeff72392 · November 25, 2015

I believe the best way to describe the way the truck shifts is "Awkwardly". its all over the place with downshift and upshift points, sometimes it will hold the gear (espicially 1st) and hit 2nd pretty hard. anyway i can bring it to the dealer and have them retune the TCM for better shifting? oh,and to add to the rough shifting, it seems to be worse when the tranny is cold.

Haus_Z71 · November 28, 2015

Just got done with a 350 mile round trip. Had just about every variable driving condition. I just can't believe GM signed off on this programming for a transmission. It's far worse than any vehicle I have driven. The "learning" process has done nothing but make the shifting absolutely retarded. I wish I could drop the learning part and just stick with how it shifts from a factory reflash!

pm26 · November 29, 2015

Well, they programmed everything for maximum fuel economy at the expense of driving enjoyment! Enjoy!

andyhaug · November 29, 2015

Well, they programmed everything for maximum fuel economy at the expense of driving enjoyment! Enjoy!

But it doesn't do any better than my previous truck in an in town situation. I think the transmission awkwardness actually causes it to get worse mileage.

nadrojcote · November 29, 2015

I hands down got worse city mpg with my sierra in my small town stop and go driving than I do with my 2015 f150. It also shifts so smooth you cant feel it I have to look at the number on the dic to see which gear I'm in. I really liked my sierra and its interior, but I love my f150.