Time to start saving up for rebuild or new transmission?

[iboughtatahoe23]

I’ve looked at the AFM disabler plug in, and I’ve read good things. Just not sure where to put my money. What more important to check out first.

 

[NickTransmissions]

1. The gas pedal feels like a brick when taking off...

Sounds like possibly dirty throttle body, failing TPS or something related. If you had a speed sensor code, you should have replaced the speed sensors unless that was already done and the code was simply stored in the PCM's history.
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When you say "late shifting and slipping" when exactly is this happening? What gears and under what circumstances?


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My Tahoe also sounds like a big whirling turbine at very low speeds and quiets down afterwards and if yours is the same type of noise, that's normal. If you're hearing distinct, metallic whirling sounds coming from the trans, that could be 4-5-6 clutch hub coming apart but that sounds is distinct from the whirling turbine sound heard at take-off.

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You need to get your Tahoe scanned w/a scanner that can read transmission codes and display live data (most shops will have these; a TECH2 is ideal but any Snap-On, OTC or other higher end scan tool will work, for diagnosis anyway. Look out for any P0700+ codes especially as most of those are either TEHCM, Valve body or gear ratio error codes.

I'd also start saving for an overhaul or replacement transmission simply because the mileage on your truck is around the time they like to shit the bed.

I’ve looked at the AFM disabler plug in, and I’ve read good things. Just not sure where to put my money. What more important to check out first.

Fix your other shit first - get the vehicle working correctly before you start modding things (unless you can bet your life on a mod actually solving your problems as described).

 

[iboughtatahoe23]

So what’s the tech 2 gonna show me that my current scanner won’t?

 

[iboughtatahoe23]

Sounds like possibly dirty throttle body, failing TPS or something related. If you had a speed sensor code, you should have replaced the speed sensors unless that was already done and the code was simply stored in the PCM's history.
----

When you say "late shifting and slipping" when exactly is this happening? What gears and under what circumstances?


-----
My Tahoe also sounds like a big whirling turbine at very low speeds and quiets down afterwards and if yours is the same type of noise, that's normal. If you're hearing distinct, metallic whirling sounds coming from the trans, that could be 4-5-6 clutch hub coming apart but that sounds is distinct from the whirling turbine sound heard at take-off.

----
You need to get your Tahoe scanned w/a scanner that can read transmission codes and display live data (most shops will have these; a TECH2 is ideal but any Snap-On, OTC or other higher end scan tool will work, for diagnosis anyway. Look out for any P0700+ codes especially as most of those are either TEHCM, Valve body or gear ratio error codes.

I'd also start saving for an overhaul or replacement transmission simply because the mileage on your truck is around the time they like to shit the bed.



Fix your other shit first - get the vehicle working correctly before you start modding things (unless you can bet your life on a mod actually solving your problems as described).

So you’re saying the ZR8 Won’t show these codes? I should return it and get a different one? Or what.

 

[iboughtatahoe23]

Wouldn’t have one of the three mechanic to look at my vehicle had to have har a scanner line that? And they said no codes

 

[NickTransmissions]

So you’re saying the ZR8 Won’t show these codes? I should return it and get a different one? Or what.

Have no experience w/that tool so can't say.

Sounds like you may have two separate problems but hard to say for sure...Here's what I would do, if I were you:

1) Diagnose and fix the stiff accelerator pedal issue first as that may or may not be causing all of your problems, including your shifting concerns w/the transmission.

2) Once you complete step 1 and you still have issues with the trans, you can try having a reflash update or adapt procedure done to see if that works.

If it doesnt then I'd pull the trans and go through it, installing all of the requisite cures and updates - i can provide a list if you need it.

I'll have a few "demo" videos on working on a 6L80e that will show the step by step process taking apart and reassembling the trans on my YT channel next week sometime.

Alternatively, you can replace it with a remanufactured unit
Most folks on here (and in general) purchase either GM or Jasper transmissions. Or you can have a local shop rebuild it (just make sure they can do the fast-adapt relearn procedure give a one year or more warranty).

 

[iboughtatahoe23]

Have no experience w/that tool so can't say.

Sounds like you may have two separate problems but hard to say for sure...Here's what I would do, if I were you:

1) Diagnose and fix the stiff accelerator pedal issue first as that may or may not be causing all of your problems, including your shifting concerns w/the transmission.

2) Once you complete step 1 and you still have issues with the trans, you can try having a reflash update or adapt procedure done to see if that works.

If it doesnt then I'd pull the trans and go through it, installing all of the requisite cures and updates - i can provide a list if you need it.

I'll have a few "demo" videos on working on a 6L80e that will show the step by step process taking apart and reassembling the trans on my YT channel next week sometime.

Alternatively, you can replace it with a remanufactured unit
Most folks on here (and in general) purchase either GM or Jasper transmissions. Or you can have a local shop rebuild it (just make sure they can do the fast-adapt relearn procedure give a one year or more warranty).

Ok I will double check that last part. And I will sub to your channel. Would the throttle body be a good place to start?

 

[CM_2016Tahoe]

Hi, I'm new to this forum. I have a 2016 Chevy Tahoe with 83,000 miles. At the end of April, I noticed that my truck would stutter/shudder/vibrate at certain speeds while accelerating, but it never set a code. I initially thought it was bad fuel, so I took the truck to my dealership where I purchased the truck in 2019 as a certified pre-owned vehicle. I was told that it was an “engine misfire” with a code of P0300 and that I needed a throttle bottle service, fuel injection service, and a fuel quality/methanol check. I was told that if I did not get the repair done, “it will continue to run the way it is and can affect the motor.” The bill for this repair would be $762 plus tax. Thankfully, I decided to get a second opinion. I took my Tahoe to a local auto repair shop and what they found was quite a shock to me. They told me that my torque converter was faulty and that it needed to be replaced. They told me that this was a “common issue” found in GM vehicles ranging from 2015-2019 and that there is a Technical Service Bulletin on it as well as some class-action lawsuits. After doing some research on the internet, I found countless truck forums with GM owners complaining of this issue on trucks with 110,000 or less just like mine.
The auto shop recommended I take the truck to a transmission shop - the guy there totally rebuilt my trans to eliminate all the GM "weak links" and put in a stronger torque converter. Problem solved! Set me back $5,000!! I couldn't believe what my dealership was trying to sell me. I am so disappointed in them. The mechanics who figured out the issue told me my truck is in great shape otherwise and I should be good from here on out.

 

[iboughtatahoe23]

Hi, I'm new to this forum. I have a 2016 Chevy Tahoe with 83,000 miles. At the end of April, I noticed that my truck would stutter/shudder/vibrate at certain speeds while accelerating, but it never set a code. I initially thought it was bad fuel, so I took the truck to my dealership where I purchased the truck in 2019 as a certified pre-owned vehicle. I was told that it was an “engine misfire” with a code of P0300 and that I needed a throttle bottle service, fuel injection service, and a fuel quality/methanol check. I was told that if I did not get the repair done, “it will continue to run the way it is and can affect the motor.” The bill for this repair would be $762 plus tax. Thankfully, I decided to get a second opinion. I took my Tahoe to a local auto repair shop and what they found was quite a shock to me. They told me that my torque converter was faulty and that it needed to be replaced. They told me that this was a “common issue” found in GM vehicles ranging from 2015-2019 and that there is a Technical Service Bulletin on it as well as some class-action lawsuits. After doing some research on the internet, I found countless truck forums with GM owners complaining of this issue on trucks with 110,000 or less just like mine.
The auto shop recommended I take the truck to a transmission shop - the guy there totally rebuilt my trans to eliminate all the GM "weak links" and put in a stronger torque converter. Problem solved! Set me back $5,000!! I couldn't believe what my dealership was trying to sell me. I am so disappointed in them. The mechanics who figured out the issue told me my truck is in great shape otherwise and I should be good from here on out

Wow

 

[NickTransmissions]

Ok I will double check that last part. And I will sub to your channel. Would the throttle body be a good place to start?

Thanks - the TB is a good a place as any as it may be dirty and/or in need of service.

What you need is a scanner with live data feeds that can stream the data as you're driving. If your scan tool is capable of that, stick it on the vehicle then drive it around as see what it displays. Also thorougly check around the acc pedal for any mechanical issues, broken parts etc.

 

[NickTransmissions]

Hi, I'm new to this forum. I have a 2016 Chevy Tahoe with 83,000 miles. At the end of April, I noticed that my truck would stutter/shudder/vibrate at certain speeds while accelerating, but it never set a code. I initially thought it was bad fuel, so I took the truck to my dealership where I purchased the truck in 2019 as a certified pre-owned vehicle. I was told that it was an “engine misfire” with a code of P0300 and that I needed a throttle bottle service, fuel injection service, and a fuel quality/methanol check. I was told that if I did not get the repair done, “it will continue to run the way it is and can affect the motor.” The bill for this repair would be $762 plus tax. Thankfully, I decided to get a second opinion. I took my Tahoe to a local auto repair shop and what they found was quite a shock to me. They told me that my torque converter was faulty and that it needed to be replaced. They told me that this was a “common issue” found in GM vehicles ranging from 2015-2019 and that there is a Technical Service Bulletin on it as well as some class-action lawsuits. After doing some research on the internet, I found countless truck forums with GM owners complaining of this issue on trucks with 110,000 or less just like mine.
The auto shop recommended I take the truck to a transmission shop - the guy there totally rebuilt my trans to eliminate all the GM "weak links" and put in a stronger torque converter. Problem solved! Set me back $5,000!! I couldn't believe what my dealership was trying to sell me. I am so disappointed in them. The mechanics who figured out the issue told me my truck is in great shape otherwise and I should be good from here on out.

Good call - glad you found a competent shop...A shop/builder who knows these units can build a much better unit w/all the required updates for less than a reman unit in most cases.

Those converters are junk as they come from the factory but a rebuild w/a .050-.070 converter clutch and stronger stator/owc makes a world of difference. That and a lower thermostat for the trans or deleting it all together.

 

[iboughtatahoe23]

Thanks - the TB is a good a place as any as it may be dirty and/or in need of service.

What you need is a scanner with live data feeds that can stream the data as you're driving. If your scan tool is capable of that, stick it on the vehicle then drive it around as see what it displays. Also thorougly check around the acc pedal for any mechanical issues, broken parts etc.

I have live data available. What banks can I look at ? Can also graph data.

 

[iboughtatahoe23]

Thanks nick.

 

[NickTransmissions]

I have live data available. What banks can I look at ? Can also graph data.

@swathdiver and others can answer this question more thorougly than I can but you want to compare the tps % to reality using the scanner. There are other parameters as well but admittedly, I'm not an expert at diagnosing non-trans specific issues as i only do bench builds (i never actually see the vehicles themselves).

 

[iboughtatahoe23]

@swathdiver and others can answer this question more thorougly than I can but you want to compare the tps % to reality using the scanner. There are other parameters as well but admittedly, I'm not an expert at diagnosing non-trans specific issues as i only do bench builds (i never actually see the vehicles themselves).

I see, right here I got 17% To 17.6 % steady at idle. Not sure what to compare that to.

 

[iboughtatahoe23]

Apparently 5-20% range for the tps is normal. But certain factors come into play. Is it worth looking at the throttle body with 166k?

 

[iboughtatahoe23]

Thanks - the TB is a good a place as any as it may be dirty and/or in need of service.

What you need is a scanner with live data feeds that can stream the data as you're driving. If your scan tool is capable of that, stick it on the vehicle then drive it around as see what it displays. Also thorougly check around the acc pedal for any mechanical issues, broken parts etc.

Other things to check? Before moving to step 2. I changed idler pulley, serpentine belt and cleaned maf sensor so far.


Edit: trying to fix rough idle as wel as the transmission issues I’m having.

Kinda taking it all on at once.

 

[NickTransmissions]

Other things to check? Before moving to step 2. I changed idler pulley, serpentine belt and cleaned maf sensor so far.


Edit: trying to fix rough idle as wel as the transmission issues I’m having.

Kinda taking it all on at once.

Resolve all non-transmission issues first, in whichever order you want to tackle them in. Engine itself has to be running right, gas pedal normal, TB/MAF/O2s/etc should all look and function normal.

Once you have resolved your engine and gas pedal symptoms then you can move onto the trans. This way, if it's shifting odd, slipping, clunking, shuddering, banging or flairing you know its the trans and not something else.

Bottom line - if you're slipping as mentioned in one of your previous posts [you havent yet told me when you have observed it slipping or what gear(s)] the transmission is on it's way out and will need an overhaul.

Keep us posted; perhaps others will chime in on your rough idle and gas pedal problems.

 

[swathdiver]

I see, right here I got 17% To 17.6 % steady at idle. Not sure what to compare that to.

That's really high. Has the throttle body been off and cleaned recently? If so, it may take a few drive cycles for it to adjust. BlackBear if memory serves, didn't like more than 10% and mine has historically been around 7%. Most are around 3% and that's what BB was looking for.

The dirtier the throttle plate coking, the more it will open to compensate over the life of the vehicle.

 

[iboughtatahoe23]

“Based off your post history, you have a 2014 Tahoe, a tech 2 is not compatible with anything 2014+, they use an MDI and GDS software. Most code reader can read transmission codes I have a $40 reader from Napa that works just fine for reading trans codes.”

-a Redditor from r/askmechanics