Transmission problem

[Npd15]

So I have a 2014 Sierra and lately I noticed a squeal under my engine area. No pulleys bad and belt is fine. Sounded more like fluid squeezing through something. I took it to the dealership and they pulled the dipstick for trans fluid and advised he noticed metal pieces on his fingers. Obviously not good making up there. My issue is they claim even under factory warranty they might just rebuild instead of replace!? To me that's BS...I have factory powertrain yet, only 25k miles...thoughts? And do these trucks have bad trans in them? First GMC for me...

[diyer2]

Sorry to hear this.

Rebuilds are the norm on trans and motors IMO.

Lots of transmissions that haven't had issues.

8 or 6 speed trans?

 

 

 

[gone_fishing]

I haven't heard of many 6L80 transmission failures. I would think the next step would be to drop the pan and inspect filter and fluid.

[Npd15]

40 minutes ago, gone_fishing said:

I haven't heard of many 6L80 transmission failures. I would think the next step would be to drop the pan and inspect filter and fluid.

I'm pretty sure it's the 6 speed not 8 but I could be wrong. It goes in tomorrow to drop the pan and check it all over. Fingers crossed it's not bad at all or it's terrible and they replace it lol

[diyer2]

WOW

I'm pretty sure it's the 6 speed not 8 but I could be wrong.

[gone_fishing]

11 minutes ago, Npd15 said:

I'm pretty sure it's the 6 speed not 8 but I could be wrong. It goes in tomorrow to drop the pan and check it all over. Fingers crossed it's not bad at all or it's terrible and they replace it lol

The 6L80 is a six speed. Don't believe they offered an 8 speed in 2014.

[diyer2]

I don't know.

4 minutes ago, gone_fishing said:

The 6L80 is a six speed. Don't believe they offered an 8 speed in 2014.

 

[Npd15]

It's the 6 speed. It sounds real bad when I start the truck while cold...it's weird, never had a transmission issue with any vehicle I owned till now

[mmrbad]

My 2017 V6 Silverado single cab WT transmission seems to chatter at slow speeds. My drive to work is on narrow crooked roads for 14 miles and can seldom get to 45 MPH. Occasionally I have been putting it in low and manually shifting it to stop the constant shifting up and down in auto mode. Afraid the constant slowing down for the curves and the other slow drivers on these country roads will eventually kill the tranny. I have never seen a trans shift as much as this one. It will go through all 6 up and down within a 1/4 mile just letting off the gas and letting it coast down before the curves and re-accelerating to 35 mph before the next one. Wish a manual Trans was an option. With a manual I could just leave it in 3rd and run the worst 4 miles of the curves at 30 mph without shifting. Anyone else had a chattering at slow speeds? The truck has only 16,000 miles on it.

[Grumpy Bear]

11 hours ago, mmrbad said:

My 2017 V6 Silverado single cab WT transmission seems to chatter at slow speeds. My drive to work is on narrow crooked roads for 14 miles and can seldom get to 45 MPH. Occasionally I have been putting it in low and manually shifting it to stop the constant shifting up and down in auto mode. Afraid the constant slowing down for the curves and the other slow drivers on these country roads will eventually kill the tranny. I have never seen a trans shift as much as this one. It will go through all 6 up and down within a 1/4 mile just letting off the gas and letting it coast down before the curves and re-accelerating to 35 mph before the next one. Wish a manual Trans was an option. With a manual I could just leave it in 3rd and run the worst 4 miles of the curves at 30 mph without shifting. Anyone else had a chattering at slow speeds? The truck has only 16,000 miles on it.

Define 'chatter'.  It sounds like your calling frequent shifts  or gear hunting chatter. Take your service rep for a ride.  

[pickmeup]

19 hours ago, mmrbad said:

My 2017 V6 Silverado single cab WT transmission seems to chatter at slow speeds. My drive to work is on narrow crooked roads for 14 miles and can seldom get to 45 MPH. Occasionally I have been putting it in low and manually shifting it to stop the constant shifting up and down in auto mode. Afraid the constant slowing down for the curves and the other slow drivers on these country roads will eventually kill the tranny. I have never seen a trans shift as much as this one. It will go through all 6 up and down within a 1/4 mile just letting off the gas and letting it coast down before the curves and re-accelerating to 35 mph before the next one. Wish a manual Trans was an option. With a manual I could just leave it in 3rd and run the worst 4 miles of the curves at 30 mph without shifting. Anyone else had a chattering at slow speeds? The truck has only 16,000 miles on it.

Place it in M 4 and you will enjoy it much better on that road . These transmissions are always trying to get to a higher gear especially with a soft touch of the pedal.

[mmrbad]

8 hours ago, Grumpy Bear said:

Define 'chatter'.  It sounds like your calling frequent shifts  or gear hunting chatter. Take your service rep for a ride.  

Like running over ripples on the road, Similar to the ones on the shoulder to alert you you're about to go ditch running.

[mmrbad]

1 hour ago, pickmeup said:

Place it in M 4 and you will enjoy it much better on that road . These transmissions are always trying to get to a higher gear especially with a soft touch of the pedal.

That's what I've been doing. It only runs at 1000 RPM at 35 -40 MPH.

[mmrbad]

Turns out the engine was going into V4 mode at 35 MPH in drive. The engine feels like it is miss firing at such a low speed, Hence the shuddering and chattering feeling.

[SS502]

On 1/3/2019 at 6:42 PM, mmrbad said:

Turns out the engine was going into V4 mode at 35 MPH in drive. The engine feels like it is miss firing at such a low speed, Hence the shuddering and chattering feeling.

If you’ve been driving it in M4 it should not even activate the AFM (V4) as I understand it??