GMC torque converter

[PNW bow hunter]

These trucks do also have a lot of lifter and cylinder head problems after 100k miles.

They also get a ton of carbon build up for some reason that can create lack of power, ruff idle, and the miss fires.

Put a bottle of concentrated Chevron Techron fuel system cleaner in your tank the next two times you fill it up. Two tanks of gas with a bottle of that fuel system cleaner in each one really cleans these motors out. That should give you a good smooth idle and a little more power.

 

[browning2480]

You can have the Displacment on Demand thing tuned out if you want. That is what I would do. Those 5.3s will run forever. Don’t let the Toyota guys scare you. You should also be able to fine a local shop to rebuild that trans for much less than the 5k someone else mentioned. Stop going to the dealer for things and find a good local shop. Black Bear Performance can tune your truck and set you up good.

 

[cardiac5]

The shop that I got a test drive is 1650 for torque converter, 3650 to rebuild the tranny and gives me 12month 12k mile warranty. For 4400 he’ll put a me a new gm one in with 3yr 100k mile warranty. The other 2 shops were more expensive then a dealer. The dealer wants 2400 for the TC And 5400 new tranny. Another shop wants 3500 for TC and 5600 for new tranny. I will be getting the AFM deleted also.


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[dubllung4]

Same symptoms on my '14 with the exact same mileage. Torque converter puked and ruined the tranny. Ended up paying about 2700 for a new torque converter and rebuilt transmission. Sold the truck shortly after. Very common problem, the trans shop had 3 other trucks in for the same thing when they did mine.

 

[Squincher]

I've learned over the years to do two or three drain and fills on transmissions every 30K to 50K miles, even if the manufacturer calls it a lifetime fill. It is getting harder to do these days with a lot of vehicles requiring a scanner to monitor transmission temp to get the fill level right, but an ounce of prevention is still worth a pound of cure.

 

[Mudslinger]

Looking for some advice. My truck started occasional split second vibrating (like a faint rumble strip) and has a slight sporadic knock when pulling hills . It started late Friday night on a 20hr road trip ( I’m a traveling ER nurse so I do a lot of hwy miles). It does great on acceleration and shifting. I was told from a shop over the phone it’s a torque converter. Everyone seems to be booked out several days and I work 12hr shifts so it’d be a week before it gets in. It’s a 14 Sierra 5.3 v8 4x4 with 146k miles. I was quoted $3500 for the torque converter and pump replacement. It’s $5400 for a new transmission at the dealer with warranty. Another shop said $2500 or $3650 for a rebuild. I had looked at diesels and talked myself out of it and was offered 18 trade in months ago. What happens if I keep driving it? Will the transmission just blow or what? Also do I have it rebuilt or will the torque converter be enough? I love my truck and I don’t want to get rid of it especially with prices now. When the first guy said $3500 “here come goodbye” by rascal flatts popped in my head lol. I don’t know much about this so any advice is appreciated.


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I had the same thing last year on my 17 Chevy. They told me a torque converter is fairly common thing to go wrong. I had 108k miles but mine would have a little slip in the shifting. It ended up being the transmission. I ended up rebuilding the transmission and replaced all the plugs. They did give me 100k mile warranty with the tranny rebuild.

If you do sell, you could try Carvana also. That is how I got rid of mine and they gave me a decent deal. They gave me a quote online and all I had to do was give them mileage and year. They gave me a week or ten day quote and its no hassle.

I did the 1/2 ton diesel route now, so that is a change for me as I haven't had a diesel since I drove one in the early 90's

 

[Pdog06]

Guy I work with just had his torque converter replaced in his 2016 Sierra. Took it to a local shop that is very reputable and been doing it forever. Guy had a stack of about 40 new GM converters in the corner just for these trucks! Said he sees the issue all the time. Not sure what he paid for the repair.

2 mo the after he got it fixed he traded it in on a 2500 diesel.

I have an 08 Sierra.....so far so good with 135k on it.

 

[DWhitt]

I do Tranny's for a living...You have a 6L80e trans and the vibration is the torque converter clutch slipping during the PWM(pulse with modulation). Most manufactures use pwm to gradually put the lock up clutch on which overtime in the case of the 6L's gets destroyed by the rubbing of the dampener inside the converter. It makes tons of metal inside the trans especially the pump where the cooler return line runs back into the pump. If you are going to keep the truck do yourself a favor and get it rebuilt right with a BILLET converter and find someone that has HP Tuning and tune the TCM to not lock up til 5th and 6th gear not 2-6 like its programed from the factory. PM me if you have any questions. I have done 8 this week at my shop if that tells you its a common problem.....

 

[Pdog06]

Well that about sums it up!

 

[cardiac5]

Checked the compression yesterday. #1-145, #2-130, #3-138, #4-145, #5-170, #6-160, #7-165, #8- 168. Out of the odd cylinder plugs on the driver side #7 has a black area with a brown outline which doesn’t look good being i changed that side out completely on 5/4. The engine has also started making a high pitch whine within a few hundred rpms before its shifts in the first 2-3 gears I wouldn’t think the wine is transmission related but I’m not sure.

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[Silveroddo]

From my understanding disabling the AFM is something you want to do when the truck is new or low miles, if you wait too long the damage is done.