5.3L 8 Speed Shudder (I know I searched)

HapaTrailBoss · August 5, 2019

Like everyone else... my 8 speed was acting up when I first got my truck. I'm at 11k miles now and it smoothed out from the kick and jolting at low speeds.

Yesterday the wife and I towed our RZR 1000 with our 12' trailer in tow mode and immediately while accelerating under light throttle between 25-55mph a shudder was present.

I couldn't find anything specific to towing and shuddering in tow mode only.

Anyone else experience the same thing? Could it just be another software issue since I don't tow that often?

TIA..

Sin City Trail Boss · August 6, 2019

What is the build date on yours? Have you had GM put the new Mobile 1 in there?

MDSilveradoGuy · August 6, 2019

Now that you mention while towing - it makes me wonder if I am experiencing the shudder and misplacing the feeling as a minor engine vibration.

I tow about ~4,700lb 200 or so miles every weekend - altitudes from sea level to about 4,000 feet depending on where we are taking the boat to. I've noticed the shudder on some of the mountain climbs but just figured it was a bit of powertrain throb (the 2.7 is smooth, but there's only so much you can do to quell the vibrations of a big 4). I will pay more attention and see if this is what I am experiencing.

Question - in traffic from 15 mph or so when coasting down, I feel a minor vibration. Is this considered part of the shudder?

HapaTrailBoss · August 6, 2019

15 hours ago, Sin City Trail Boss said:

What is the build date on yours? Have you had GM put the new Mobile 1 in there?

1/2019 Original fluid.

4 hours ago, MDSilveradoGuy said:

Now that you mention while towing - it makes me wonder if I am experiencing the shudder and misplacing the feeling as a minor engine vibration.

I tow about ~4,700lb 200 or so miles every weekend - altitudes from sea level to about 4,000 feet depending on where we are taking the boat to. I've noticed the shudder on some of the mountain climbs but just figured it was a bit of powertrain throb (the 2.7 is smooth, but there's only so much you can do to quell the vibrations of a big 4). I will pay more attention and see if this is what I am experiencing.

Question - in traffic from 15 mph or so when coasting down, I feel a minor vibration. Is this considered part of the shudder?

I would liken a shudder to jerkiness just more consistent and "controlled" so to speak. While coasting down it's pretty smooth. Only in tow mode and accelerating between 25-55mph.

Keep an eye on it, I'd like to know.

Wheelguy · August 7, 2019

Really feel for you guys. I had some of the same symptoms with my 2016 Sierra 1500 SLT 5.3L 8 speed (traded). Not so much the shuddering but did have the hard shifting & a couple of times in low gears it lurched forward so hard I thought I'd been hit from behind. At around 35k to 40k miles, I experienced fish bite when cruising at normal highway speeds (feels like truck is missing out or going over very small bumps/worn down rumble strip) which would come and go - thread(s) on this site about it. Took it into dealer & they flushed the fluid & cleaned the magnet and sent me back home. Never had an issue with the biting but the hard shifting & occasional lurch didn't go away.

What I find very interesting is this is about the time when GM suddenly dropped their powertrain warranty from 5yr/100k mi to 5/60k (2016 - K2XX platform). Food for thought, maybe? I hope those involved in the class action lawsuit win because GM does seem to be stalling with this one. This issue has been present for around 5 years now AFAIK, across 2 generations & GM seems to have done nothing more to try & fix it.

HondaHawkGT · August 9, 2019

On 8/7/2019 at 10:01 AM, Wheelguy said:

What I find very interesting is this is about the time when GM suddenly dropped their powertrain warranty from 5yr/100k mi to 5/60k (2016 - K2XX platform). Food for thought, maybe? I hope those involved in the class action lawsuit win because GM does seem to be stalling with this one. This issue has been present for around 5 years now AFAIK, across 2 generations & GM seems to have done nothing more to try & fix it.

GM cut the warranty because nobody else was offering a 5 year/100k mile warranty besides them and FCA. It was purely a move to make investors happy, nothing to do with any particular powertrain component. Hence why they also dropped the free 2 year maintenance program that came 4 free oil changes at the same time they changed the warranty.

On 8/5/2019 at 1:30 PM, HapaTrailBoss said:

Yesterday the wife and I towed our RZR 1000 with our 12' trailer in tow mode and immediately while accelerating under light throttle between 25-55mph a shudder was present.

How light was the throttle? Did it shudder if you applied slightly more throttle? Was the AC on?

At light throttle, there's a good chance that cylinders are being deactivated and that's what you're actually feeling. Especially if there's just enough load that it goes into the V4 pattern that AFM uses. That cylinder deactivation pattern is the most likely to be sensed. You can also try running a higher octane fuel to see if that helps, especially since you're in Arizona, towing, and most likely have the AC on. All three can combine to cause the engine to run a little harsher since there's a lot more load on it.

Wheelguy · August 9, 2019

29 minutes ago, HondaHawkGT said:

GM cut the warranty because nobody else was offering a 5 year/100k mile warranty besides them and FCA. It was purely a move to make investors happy, nothing to do with any particular powertrain component. Hence why they also dropped the free 2 year maintenance program that came 4 free oil changes at the same time they changed the warranty.

I read that article where that statement was made and they felt those things weren’t helping sell vehicles. Not completely jumping on the conspiracy theory bandwagon but we all know no one ever lies about anything in the auto industry these days, right? I just found it ironic was all - nothing more.

MDSilveradoGuy · August 9, 2019

On 8/7/2019 at 11:01 AM, Wheelguy said:

At around 35k to 40k miles, I experienced fish bite when cruising at normal highway speeds (feels like truck is missing out or going over very small bumps/worn down rumble strip) which would come and go - thread(s) on this site about it.

Damnit, this is exactly what I am experiencing at times. It feels for all the world like it has a miss - and I do get that rumble strip feeling. Interestingly enough, when I get the rumble strip feeling - when I drop it to N it is still present so I thought it was something with my tires.

HapaTrailBoss · August 19, 2019

On 8/9/2019 at 12:06 AM, HondaHawkGT said:

How light was the throttle? Did it shudder if you applied slightly more throttle? Was the AC on?

At light throttle, there's a good chance that cylinders are being deactivated and that's what you're actually feeling. Especially if there's just enough load that it goes into the V4 pattern that AFM uses. That cylinder deactivation pattern is the most likely to be sensed. You can also try running a higher octane fuel to see if that helps, especially since you're in Arizona, towing, and most likely have the AC on. All three can combine to cause the engine to run a little harsher since there's a lot more load on it.

Throttle was approx 25-40% AC on.

It felt like a rumble strip which made me think it was related to the transmission specifically. I would experience this very infrequently going from reverse to drive as well if I don't give the truck a short pause when shifting and just applying the throttle. Shudder for 10-15 feet then just go away.

Sorry for the late reply, been inundated with work.

HondaHawkGT · August 20, 2019

8 hours ago, HapaTrailBoss said:

Throttle was approx 25-40% AC on.

It felt like a rumble strip which made me think it was related to the transmission specifically. I would experience this very infrequently going from reverse to drive as well if I don't give the truck a short pause when shifting and just applying the throttle. Shudder for 10-15 feet then just go away.

Sorry for the late reply, been inundated with work.

I just saw this manufacturer communication earlier today. Sounds like some 2019 GM trucks got the old transmission fluid, so you might have the same transmission fluid moisture issue that created a shudder in previous model years.

MC-10163241-9999.pdf

econometrics · August 20, 2019

1 hour ago, HondaHawkGT said:

I just saw this manufacturer communication earlier today. Sounds like some 2019 GM trucks got the old transmission fluid, so you might have the same transmission fluid moisture issue that created a shudder in previous model years.

MC-10163241-9999.pdf 531.48 kB · 9 downloads

My build date was 1 Feb 2019, so I definitely have the older fluid. I haven’t noticed any issues, though... which is why I didn’t bother with them flushing it out at my 3500 mile first oil change. Maybe I’ll have them do it at 7K, though, along with my first rotation.

Moledigger2019 · August 20, 2019

I have this same vibration. Sounds like a rumble strip as stated earlier. I can duplicate it using cruise control around 45 50 55. It comes and goes. Also notice small tach fluctuations. This is a trailboss lt l84 8 speed.

jordanl010 · August 22, 2019

Hey All,

New owner here (just purchased last night) 2019 GMC Sierra 1500 SLE. 5.3L V8. Driving home from the dealer I noticed no issues. Manly side roads with no high speed driving. This morning driving to word on the highway I noticed between 50-60 mph there was a slight vibration. No sounds but just a vibration coming from the vehicle. Shaking my water bottle and my self. Nothing too severe but not too comfortable. Is this something that anyone has had before?

eppieguy · August 22, 2019

Yeah, a couple have reported poor balancing of the tires, take it back and ask for a rebalance. I’d as to either watch them check the balance on the tires before they rebalance, or at minimum give you the before and after numbers.

jordanl010 · August 22, 2019

1 hour ago, eppieguy said:

Yeah, a couple have reported poor balancing of the tires, take it back and ask for a rebalance. I’d as to either watch them check the balance on the tires before they rebalance, or at minimum give you the before and after numbers.

Cool, thanks for the info! Ill start there.