2018 Yukon, tune to help trans?

[88lance]

Hey everyone, got a 2018 Yukon with a 6.0. The only issue I am running into, is that it slams into 3rd sometimes pretty hard. Long story short, dealer says it's fine, even though it's clearly not shifting correctly. They aren't going to do anything about it.

Well, back in 2011 I had an F150 that was doing this exact thing. Dealer "fixed it" about 5 times, and it just kept coming back. They just gave up on it.
Well, I was itching for more 5.0 power, and got a tuner, 5-Star Tunes for performance. It mentioned that it also changed the way the trans shifts, even though that's not what I was really buying it for.
Well, surprise, it fixed the shift problem. Completely. Shifted smooth as could be for the next 100k miles till I sold it.
So now with this Yukon giving me the same crap, I'm wondering if this could be the fix again. So I have a couple questions since I haven't had many GMC's.

-who are the top dogs in tuning for the 6.0? I would prefer somebody that has made a good name for themselves since a crap-tune can damage a lot of expensive stuff. I'll drop the necessary money for one.

-Do the tunes for these 6.0's also change the transmission, like they do in the Fords? I'm not really looking for performance in the trans, I just want it to teach it to shift correctly like it did on the F-150.

-Im not really looking for a huge power increase in the 6.0, it scoots pretty well already, but if they have a tune that gives it a little more "go" while it's helping the trans, that's would be nice. What tunes would you suggest ordering from the tuner you recommend?

 

[Doubeleive]

Hey everyone, got a 2018 Yukon with a 6.0. The only issue I am running into, is that it slams into 3rd sometimes pretty hard. Long story short, dealer says it's fine, even though it's clearly not shifting correctly. They aren't going to do anything about it.

Well, back in 2011 I had an F150 that was doing this exact thing. Dealer "fixed it" about 5 times, and it just kept coming back. They just gave up on it.
Well, I was itching for more 5.0 power, and got a tuner, 5-Star Tunes for performance. It mentioned that it also changed the way the trans shifts, even though that's not what I was really buying it for.
Well, surprise, it fixed the shift problem. Completely. Shifted smooth as could be for the next 100k miles till I sold it.
So now with this Yukon giving me the same crap, I'm wondering if this could be the fix again. So I have a couple questions since I haven't had many GMC's.

-who are the top dogs in tuning for the 6.0? I would prefer somebody that has made a good name for themselves since a crap-tune can damage a lot of expensive stuff. I'll drop the necessary money for one.

-Do the tunes for these 6.0's also change the transmission, like they do in the Fords? I'm not really looking for performance in the trans, I just want it to teach it to shift correctly like it did on the F-150.

-Im not really looking for a huge power increase in the 6.0, it scoots pretty well already, but if they have a tune that gives it a little more "go" while it's helping the trans, that's would be nice. What tunes would you suggest ordering from the tuner you recommend?

you do not have a 6.0 it's either a 5.3 or 6.2 (unless someone did a custom swap)
in either case blackbear performance can help you out.
@BlackBearPerf

 

[88lance]

you do not have a 6.0 it's either a 5.3 or 6.2 (unless someone did a custom swap)
in either case blackbear performance can help you out.
@BlackBearPerf

Correct, 6.2, sorry. Got used to Ford numbers.
I'll check them out, thanks.

 

[B-train]

If you have the 8 speed, have it flushed with the new GM fluid if it hasn't been done to your knowledge. Fixed the shudder and harsh shifting occasionally in my 2017. Been great since - 90k

 

[88lance]

Seeing a lot about Diablew as well. Do both companies have hand-held tuners that they can send with loaded tunes?

 

[88lance]

If you have the 8 speed, have it flushed with the new GM fluid if it hasn't been done to your knowledge. Fixed the shudder and harsh shifting occasionally in my 2017. Been great since - 90k

This one has the 10 speed, but it may still fix it.
They wanted $800 to do the change, but if it fixes the shifting, It may be the way to go.
It's at 90,000 mi, it may actually be time for a flush anyway.

 

[B-train]

If it's never been done, it's DEFINITELY time. Stick to a 40k interval on these new ones for longevity

 

[Doubeleive]

Seeing a lot about Diablew as well. Do both companies have hand-held tuners that they can send with loaded tunes?

With BB you can use a Autocal which is a handheld

 

[88lance]

If it's never been done, it's DEFINITELY time. Stick to a 40k interval on these new ones for longevity

Wow, yeah it doesn't show that it's been done in the records, unless a random shop did it with the previous owner. I'll go ahead and put that on my list. If that will actually fix it, I may not bother with the tune on it.

 

[88lance]

With BB you can use a Autocal which is a handheld

Great, That's what I had on the Fords and I really liked it. Especially because I could return to stock if it was going into the dealership for anything that they may flash the computer for. Plug it in, return to stock, get it back, throw the tune back in