Transmission issue, but only when cold

[Erb2017]

12 hours ago, flyingfool said:

i will dig into some of the TM this weekend.. but first step in shutting off TCC 1-4th gear. i'm still understanding the software and where everything is located.  got a link to any of your suggested research vids on youtube?

 

i'm trying to figure out how to limit the amount of gear kickdown(passing gear) on the 6l80. there been times i was in Drive, stomped the pedal and i swear I'm in 2nd gear from 6th. crazy stuff.

 

 

[Erb2017]

12 hours ago, flyingfool said:

i will dig into some of the TM this weekend.. but first step in shutting off TCC 1-4th gear. i'm still understanding the software and where everything is located.  got a link to any of your suggested research vids on youtube?

 

i'm trying to figure out how to limit the amount of gear kickdown(passing gear) on the 6l80. there been times i was in Drive, stomped the pedal and i swear I'm in 2nd gear from 6th. crazy stuff.

 

 

[superdave160]

Is there a way to see what gear the transmission is in (when in D) and if the torque converter clutch is engaged?

[flyingfool]

20 hours ago, superdave160 said:

Is there a way to see what gear the transmission is in (when in D) and if the torque converter clutch is engaged?

yes, log the gear and tcc PIDS

easy japanesy!

[Pete Comeau]

2018 Denali with 8 speed trans. having same issues. Only with cold start for about 1 minute driving. Dealer has reprogrammed transmission, replaced driveshaft and reprogram, tranny flush and reprogram again to no avail.

Seems to be at its worse with light throttle but afraid it will do damage with more acceleration as the jerkiness is worrisome. 65k kilometers and now pulling 6700lb travel trailer leaves me to think troubles ahead if this issue isn’t solved. Booked once again to check rear axle and hopefully have that flushed. If no success then it’s bye bye GM for life.

[Siebersh]

On 6/23/2018 at 12:26 PM, Steven Muraoka said:

Hey all,

 

2017 Silverado, 5.3/6spd.

 

My transmission issue only happens when I first drive the truck for the first time in the morning. The truck has to have been sitting overnight for this to occur.

After starting the truck and driving, the trans will "fish bite" or stutter when shifting from third to fourth. It will do this once, (maybe twice) and be good and problem free for the rest of the day.

 

Has anyone else experienced this? It only happens when the truck is first driven after sitting overnight. It's not really a major issue, as it doesn't happen again after the first time, but it's pretty annoying. This issue only occurs at light/part throttle, and my speed is around 25-30 mph. I do not notice any variances on the tach while this happens. Also, if I drive with more pedal/throttle, I will not experience this stutter.

 

I spoke with the dealer about this when I went in for my second free oil change, and they could not replicate the issue. During my first trip to the dealer, they downloaded a program update for the transmission. It helped overall, but the isolated problem is still present in the morning. 

 

I have read somewhere on this forum, that this was a "normal" occurance, and attempts to remedy should not be attempted. I believe that post mentioned that transmission fluid temperature played some part in this.

 

Any ideas or input? Thanks in advance!

 

Steve

Hi, I have a 2020 with 2000miles and experiencing a 1-2 slip when cold it only happens on the first shift of the day...still trying to get it resolved dealer say "can't replicate the issue...I say BS!

[Notch8022]

Guys, I've have 110k on my silverado.  I watch the tranny temp on dash and seems to smooth out when you reach 110 degrees. So what I do in morning is let truck run a little then drive down my neighborhood streets in with manual mode (getting to me up and temp up) or tow mode seems to smooth it out too. Hope this helps.

[diyer2]

Well Notch, some more info may help. Has the trans been serviced? 8 speed 6 speed? 

[chill1234]

2017 1/2 silverardo

I have been dealing with this same issue for over 2 years with the dealership. they've torn the whole transmission apart twice, replaced my torque converter, pump, clutch plates, reprogramed etc etc etc. It improved slightly but I still didn't like how it was shifting and it was significantly worse when cold. My warranty is finally up so I've been going to a different mechanic now. When the relay for my wipers went and we replaced the entire fuse panel (seriously?! da**** kind of design is this) it solved the other issue. I have no idea why or if this was a happy coincidence but nonetheless I'm over the moon that my truck finally drives like new.