Hello..2009 Tahoe Z71

[thedog52]

We rarely if ever hear of a transmission shop that suggests making a repair to a transmission rather than replacing or overhauling the whole unit.

Your transmission has the ability to learn and adapt as it ages. It makes changes to line pressures and the speed at which shifts are made based on a number of factors and changes over time. Yours might just need a "Service Learn Adapts" run and or the one that gets a solenoid un-stuck. If it has not been serviced, that would be my first suggestion, a complete fluid exchange using the TransFlow machine. Some will suggest dropping the pan and changing the filter instead or in addition. To each his own.

Your transmission also has an internal oil life monitor much like one for the engine that you can see on your DIC. You can view this one on the Tech-2. Yours is probably down to the teens percentage wise. Dirty fluid wears out the solenoids quickly and they can be rebuilt rather quickly and inexpensively with the right tools.

We see this all the time, trans shops bend owners over a barrel and leave them little choice because they are ignorant of what makes one tick. Of all the parts of a car, the trans is treated like some magical box and the magicians who fix them almost always say they are shot and need replacing or rebuilding. In their defense, if something else fails, they'll get blamed so they might as well suggest the shotgun approach and replace everything.

Thanks for your reply. I will look into solenoid repair and fluid flush. My local guy does the flush for $250.

 

[thedog52]

What James said is so very very true. I also agree with him in the full fluid swap out approach.

I also agree about why the trans tech suggests a full on rebuild or replacement. Any attempt by them to just repair may make them a hero or the villain. If they attempt the repair and then even more money is needed for the full on rebuild or replacement, that would be more expense than what they had recommended in the beginning and then the owner of the vehicle wants to point fingers.

Kind of a "damned if I do and damned if I don't" scenario.

Yep, I am planning on an out of state trip soon and I have an infant. It would not be good stuck on the side of the road.

 

[swathdiver]

Thanks for your reply. I will look into solenoid repair and fluid flush. My local guy does the flush for $250.

Does that also include dropping the pan and replacing the filter? What fluid does he use? For reference, most of us pay less than $200 at the dealership for the fluid exchange.

 

[OR VietVet]

Does that also include dropping the pan and replacing the filter? What fluid does he use? For reference, most of us pay less than $200 at the dealership for the fluid exchange.

Since he said it has never been serviced, IMO, I would make sure to drop the pan and look in there and replace the filter before reassembly. Swap out all fluid as well.

 

[iamdub]

I get why you would say that, but I’ve known this guy for years and I’ve taken him a lot of work. I don’t think he would lie to me, but you could be right.

James and Ron spelled it out.

It may not be lying, just more covering his ass with what would be the surefire fix. A shop has to be careful what they choose to get involved in when the cause and/or solution of a problem isn't obvious. You bring them an ailing trans with a symptom that could be one of a trans on it's way out, and they tell you so. Technically, the trans is on it's way out just like we're all dying from the second we're born. So, there again, they're not lying. Replacing or rebuilding it would certainly fix the problem because the old fluid and (possibly) sticking solenoid would be replaced in a total replacement or rebuild. What you're trying to do is avoid throwing the baby out with the bath water.

 

[swathdiver]

James and Ron spelled it out.

It may not be lying, just more covering his ass with what would be the surefire fix. A shop has to be careful what they choose to get involved in when the cause and/or solution of a problem isn't obvious. You bring them an ailing trans with a symptom that could be one of a trans on it's way out, and they tell you so. Technically, the trans is on it's way out just like we're all dying from the second we're born. So, there again, they're not lying. Replacing or rebuilding it would certainly fix the problem because the old fluid and (possibly) sticking solenoid would be replaced in a total replacement or rebuild. What you're trying to do is avoid throwing the baby out with the bath water.

Well said Chris!

 

[thedog52]

James and Ron spelled it out.

It may not be lying, just more covering his ass with what would be the surefire fix. A shop has to be careful what they choose to get involved in when the cause and/or solution of a problem isn't obvious. You bring them an ailing trans with a symptom that could be one of a trans on it's way out, and they tell you so. Technically, the trans is on it's way out just like we're all dying from the second we're born. So, there again, they're not lying. Replacing or rebuilding it would certainly fix the problem because the old fluid and (possibly) sticking solenoid would be replaced in a total replacement or rebuild. What you're trying to do is avoid throwing the baby out with the bath water.

Yes sir! It just sucks. Haven’t had it long and now I’m looking at another expense. I love the truck though. I’ll end up replacing the trans. I can’t afford to just throw money at it and hope it’s fixed. I have a baby and I can’t be stuck on the side of the highway. I appreciate the help!

 

[thedog52]

Y’all have been great! I appreciate the replies. Once this is all over I’m thinking AFM delete with a BTR or some other cam swap. Possible turbo set up. Not entirely sure on what I’m going to do yet. Thanks for the warm welcome.

 

[isp5190]

I'm new to the Tahoe, but not new to the auto world. I have built a 64 Nova autocross car and love Harleys. I love working on things and I am a big DIYer. That being said, I need some guidance.

I recently acquired a 2009 Tahoe Z71. Unfortunately, it is now needing a new 6l80. It has 126k miles on it with a pretty good maintenance record. My trans guy told me to look for a programmer to turn off AFM and to change the programming of the trans. What do you recommend for these issues? Thank you for your help!

Our 2009 LTX started to use oil @ the rate of 1 qt every 1000 miles. I bought the Range AFM device to shut down the AFM. The transmission doesn't down shift as much going up slight grades and the oil usage is down to 1 qt every 2500 miles. It has not affected the gas mileage enough to bother me. Down side is OnStar doesn't get the info from the vehicle to send me the monthly report. If I call OnStar for an issue they have me unplug the Range to read the info. Another idea is to get someone that can reprogram the computer to delete the AFM, that way you don't have to plug anything into the OBD port. A side note, I had an Diablo disabler, it would run the battery down if left setting several days, the Range does not.

 

[thedog52]

Our 2009 LTX started to use oil @ the rate of 1 qt every 1000 miles. I bought the Range AFM device to shut down the AFM. The transmission doesn't down shift as much going up slight grades and the oil usage is down to 1 qt every 2500 miles. It has not affected the gas mileage enough to bother me. Down side is OnStar doesn't get the info from the vehicle to send me the monthly report. If I call OnStar for an issue they have me unplug the Range to read the info. Another idea is to get someone that can reprogram the computer to delete the AFM, that way you don't have to plug anything into the OBD port. A side note, I had an Diablo disabler, it would run the battery down if left setting several days, the Range does not.

Ive seen those. Im thinking about just sending my PCM into black bear or something and see what they can do with it.