6l80e 6th gear at 40mph?

Busch · March 29, 2020

Hello all. Just joined today so I apologize if this question is in the wrong section of the forum. Just getting my feet wet. Just picked up a 2010 gmc 1500 ex cab. L9h 6.2, nht max tow etc. It has 130k. Love the truck but just wanted to ask if they all do what mine is doing. On a light cruise fully warmed up, it seems like it goes into 6th gear and locks up converter and pulls the engine down to 1100rpm at 40mph. This is really my only complaint with the truck. Is it normal? Will a tuner fix? Suggestions? Thanks all.

CamGTP · March 29, 2020

Yes, that is normal.

This is a screen shot from a 2012 5.3/6L80e truck. Even with a different rear end gear ratio the results are within 1-3-mph so it doesn't really matter on that part.

Yes, a tune can fix this. I would suggest a in person tune or one done through a tuning service instead of the boxed tuners from people like superchips, diablo, SCT tuners etc etc.

Busch · March 29, 2020

Thanks man. How about the black bear tune I hear so much about? That should straighten it out.

CamGTP · March 30, 2020

I have no personal experience with them as I do my own tuning but many use them.

I'm sure if you tell them what you want they probably can help.

swathdiver · March 31, 2020

On 3/29/2020 at 8:58 AM, Busch said:

On a light cruise fully warmed up, it seems like it goes into 6th gear and locks up converter and pulls the engine down to 1100rpm at 40mph. This is really my only complaint with the truck. Is it normal? Will a tuner fix? Suggestions? Thanks all.

What's wrong with that? BlackBear tuned my engine and transmission and my favorite part of the tune is how the transmission performs now.

Busch · March 31, 2020

Just seems like its lugging alot with the factory trans settings. I have heard great stuff about black bear tunes so I may shoot them an email. Truck is 100% stock now other than an aftermarket trans cooler.

swathdiver · March 31, 2020

7 hours ago, Busch said:

Just seems like its lugging alot with the factory trans settings. I have heard great stuff about black bear tunes so I may shoot them an email. Truck is 100% stock now other than an aftermarket trans cooler.

Mine doesn't lug but you have a bigger motor. Regardless, BlackBear can fix it to your liking. Just tell them.

Busch · March 31, 2020

Good deal. I will give them a call. I must say my daily driver is a 2006 lbz with allison and it's always in the right gear so I am not used to this thing yet. Got spoiled with all of the duramax torque.

swathdiver · March 31, 2020

12 minutes ago, Busch said:

Good deal. I will give them a call. I must say my daily driver is a 2006 lbz with allison and it's always in the right gear so I am not used to this thing yet. Got spoiled with all of the duramax torque.

LBZ is my favorite Duramax.

Busch · March 31, 2020

Owned it since new. 230k miles. Runs, shifts, drives like new. 100% stock. Best truck ever made imo.

CamGTP · March 31, 2020

I set my 5th gear to 44-45mph and 6th gear at 48-49mph. It never lugs around at 40mph anymore.

Busch · April 1, 2020

That would be perfect for my truck to because it doesent seem to use 5th.

SierraHD17 · April 6, 2020

I have the same truck as a 2013 and its the same way. Oddly though otherwise its the most perfect shifting 6 speed truck I have ever driven for the most part. Just needs some clean up, speed up the wide open throttle shifts and raise the wide open shift points.

I made changes to my one guys 2014 5.3 truck for the same reason.. he hated it going into 6th under light load at such a low speed. Drastically improved even just mild around town type driving.