2017 Tahoe Trans rebuild advice?

[TireFire]

Hello all,
I’m new here so hopefully posting in the right place. Made an account to solicit some advice on my current situation.

Our 2017 Tahoe has about 127k on the odo now. Got it a few years back with about 90k and immediately turned off AFM with an OBDII dongle. I don’t think it’s ever had trans fluid changed (no drain on the pan, lol), but it didn’t ever top 195F during my ownership. Yesterday I suddenly had a bunch of neutrals, some grinding noise, and eventually CEL popped. Was able to limp it home. Codes are P0700 & P2723. Dip stick shows some fine aluminum shavings. Assuming TC grenades & took out the pump sending metal everywhere.

I’m resigning myself to the likely scenario that it’s gone (insert blown tranny joke). Found a local place that offers in-house rebuilds of MY transmission, not a swap for a remanned unit. Cost around $7k, gulp!!

TLDR,
1) what sort of upgraded parts should I ask for in the rebuild? I read Sonnax has a good rep but lost in all the details and various parts
2) Any recommendations for a torque converter? Nothing overly expensive but that will handle frequent towing of our boat (7k lbs+). Maybe something with a forged lockup piston & billet lockup plate.
3) do I need a new radiator & cooler? I have the max trailer package and the external one looks like tube & fin but not sure what’s in the radiator? Local shops all say just flush??
4) should I delete the thermal bypass mechanism or just go with the updated part from the TSB (21-NA-199)?
5) any recommendations for a mail order tuner? I have the HP tuner device but not really versed in anything other than loading tune files. I’d like to turn off AFM & perhaps keep the TCC from locking up in low speed all the time and slipping so damn much. Would like to get another 100k from the rebuilt trans.

TIA, all!!

 

[tom3]

Son just went through this with his Sierra, just over 100k miles too. Looked around, got a lot of referrals from his buddies. Took it to a transmission only shop down on the river. They put in rebuilds from a place they always use (not a Jasper), 3 year warranty. Guys says the 6L80 is really helping his retirement these days. But he says all the parts these days are from the aftermarket and are improvements over the stock OEM stuff and he always puts in an upgraded converter, eliminates the thermo valve deal. He also does the programming to eliminate the AFM, set shift points a bit different, and changes the TC lock up deal to what it should be without all the slipping. Truck is some different since the change out - and for the better. Two day turnaround. Full price all in was $5100. Son is a school teacher with 3 kids, that hurt.

 

[TireFire]

They should call it generous motors for sure. At this point I’d be happy with the relatively low price tag of $5,100. What area are you in. I’m in Western WA on the peninsula

 

[TireFire]

Bueller??

Trans shop just called and after pulling the pan confirmed that it needs a complete overhaul. $7,500 Fakkkk.

They said they use upgraded TC and bypass the thermostat on all rebuilds but recommended against tuning the TCC differently. Wonder why??

For those who’ve had theirs rebuild (not swapped in a reman), what upgrade parts did you request? Anyone have a drain plug added to the pan?

 

[NickTransmissions]

Bueller??

Trans shop just called and after pulling the pan confirmed that it needs a complete overhaul. $7,500 Fakkkk.

They said they use upgraded TC and bypass the thermostat on all rebuilds but recommended against tuning the TCC differently. Wonder why??

For those who’ve had theirs rebuild (not swapped in a reman), what upgrade parts did you request? Anyone have a drain plug added to the pan?

See my 6L80 Information Thread for upgrades (link in my sig) - I made that thread specifically for DYIers and other intereted parties to simplify and bring clarity to dealing with these transmissions.

Upgraded TC, Sonnax Zip kit (or Transgo repro kit), Sonnax billet 4-5-6 clutch hub, piston kit, 1-2-3-4 billlet piston, 3-5-R hp apply ring, etc.

 

[tom3]

Grandson has an 06 Silverado that has what looks to be a factory drain plug on his trans pan. Never seen this before, but a real common sense item. I put drains on any of my vehicles when the warranty is out. Just find a spot, usually near the magnet, drill a hole, weld a nut inside, flange head bolt and a gasket. I can still make a mess though.

 

[mikeyss]

Even with a better TC, I would insist that the TCC be programmed for zero slip, and only activate in 4-5-6 gear. There is no reason for lockup in 1-2-3 gear, plus you will still wear out the TCC - it'll just take longer with a good TC.

 

[NickTransmissions]

Even with a better TC, I would insist that the TCC be programmed for zero slip, and only activate in 4-5-6 gear. There is no reason for lockup in 1-2-3 gear, plus you will still wear out the TCC - it'll just take longer with a good TC.

Yep, a good tune should compliment the mechanical overhaul when it comes to these and other clutch-to-clutch transmisssions

 

[TireFire]

Even with a better TC, I would insist that the TCC be programmed for zero slip, and only activate in 4-5-6 gear. There is no reason for lockup in 1-2-3 gear, plus you will still wear out the TCC - it'll just take longer with a good TC.

Any recommendations for a mail order tune to do that? Or do you do this yourself with HP Tuners? I read that eliminating lockup in the low gears is key, and maybe also increasing min. lockup speed in the taller gears in addition to allowing zero slip?

 

[mikeyss]

Any recommendations for a mail order tune to do that? Or do you do this yourself with HP Tuners? I read that eliminating lockup in the low gears is key, and maybe also increasing min. lockup speed in the taller gears in addition to allowing zero slip?

I had blackbear tune my transmission. A lot of the members on here have their tunes with great results.

 

[skimask]

Bueller??

Trans shop just called and after pulling the pan confirmed that it needs a complete overhaul. $7,500 Fakkkk.

They said they use upgraded TC and bypass the thermostat on all rebuilds but recommended against tuning the TCC differently. Wonder why??

For those who’ve had theirs rebuild (not swapped in a reman), what upgrade parts did you request? Anyone have a drain plug added to the pan?

6L80 rebuild locally, with all the good stuff, T/C, plates, clutches, thermostat 'fix'x etc.etc.etc. Dropped off via tow truck @ $200, $4300 for the shop, in and out in 2 days. Done and done.

Don't know why people still **** around and try to do shit cheap and shoot themselves in the foot doing it.
Unless you are actually that good, you're not that good.

 

[TireFire]

6L80 rebuild locally, with all the good stuff, T/C, plates, clutches, thermostat 'fix'x etc.etc.etc. Dropped off via tow truck @ $200, $4300 for the shop, in and out in 2 days. Done and done.

Don't know why people still **** around and try to do shit cheap and shoot themselves in the foot doing it.
Unless you are actually that good, you're not that good.

Man, that sounds good. When was this and what area of the country? Mine looks like it’s gonna be around $7,500 for the rebuild but take about 2 weeks

 

[TireFire]

I could use some more advice & a sanity check. I feel like they are doing a bait & switch now that they have my ride in their shop with the trans out. Costs keep going up. I’m attaching their initial report and the 3 options they presented (2 rebuilds & 1 GM reman swap in)

I’m located in Western Washington near Silverdale. Are those prices reasonable? Shop rate @ $189 seems a bit elevated, but whatever. What gets me is the parts prices. Wayyyy higher than all the online sources and even much higher than the Transtar online catalog, which is their supplier. They are also not consistent for some of the same parts between the posted options. They say they can’t get me a Circle D, not the BU60FHD (which I wanted) from CVC, and obviously they won’t warranty if customer supplies parts. Big reason I brought it to a shop was to get a warranty (24/36 on rebuilds - options 1 & 2, & 36/100 on the GM reman - option 3). Also note how the machining work doesn’t include reinforcement of the 35R drum; I had slipping/no reverse.

Wwyd? Should I have my Tahoe pulled from their shop and go somewhere else?

 

[TireFire]

Bump

 

[NickTransmissions]

Bump

That bill is typical of these transmissions; labor rates here in Vegas are running between $175-225 per hour. My cost to rebuild 6L transmissions is approaching 5k; parts prices keep going up in ways I've never seen before until post-Covid.

At this point, you're pretty much stuck with them...They have the transmission apart and are about to go through it.

What was the total amount they quoted you (out the door, inclusive of all other services) for each rebuild option and how does each price as quoted compare to the above report?

Option 1-Rebuild: $x,***.00
Option 2 Rebuild: $y,yyy.00
Option 3 (GM Reaman): $z,zzz.00

Also, did they inform you that the price may go up if the transmission sustained hard part damage? If so, that's typical/normal - I do the same thing. If they didn't it's a big miss on their part, poor upfront communication and disclosure.

 

[fasteddy]

Geez...... 17 Tahoe is 6l80e. New from GM is ......$3800? approx 2WD or 4WD

I wouldn't let private shop rebuild my 6l80e, it's a very specialized skill. Very. Watch precisions transmissions on YouTube.
Here is a GM dealership that sells em online. R&R a tranny is easy. 3 hours max.

2014-2020 GM 6-Speed Automatic Transmission Assembly 19431764 | GM Parts Center

Save Big On This OEM GM 6-Speed Automatic Transmission Assembly, Part #19431764 for 2014-2020 GM. Wholesale Prices, Fast Shipping. Order Online Today!

www.gmpartscenter.net

 

[NickTransmissions]

Geez...... 17 Tahoe is 6l80e. New from GM is ......$3800? approx 2WD or 4WD

I wouldn't let private shop rebuild my 6l80e, it's a very specialized skill. Very. Watch precisions transmissions on YouTube.
Here is a GM dealership that sells em online. R&R a tranny is easy. 3 hours max.

2014-2020 GM 6-Speed Automatic Transmission Assembly 19431764 | GM Parts Center

Save Big On This OEM GM 6-Speed Automatic Transmission Assembly, Part #19431764 for 2014-2020 GM. Wholesale Prices, Fast Shipping. Order Online Today!

www.gmpartscenter.net

You seriously think there's no private/independent shops that can competently rebuild these transmissions?

LOL!

The GM Remans are the best of those on the market insofar as factory spec 6Ls are concerned but they still have all the same weaknesses that the originals did, other than a couple of updates including the HD parking rod assembly. Beyond that, a shop that's versed in these transmissions can build that same unit with upgraded parts from the aftermarket that solve many of the common pattern failures these transmissions are known for.

 

[fasteddy]

You seriously think there's no private/independent shops that can competently rebuild these transmissions?

LOL!

The GM Remans are the best of those on the market insofar as factory spec 6Ls are concerned but they still have all the same weaknesses that the originals did, other than a couple of updates including the HD parking rod assembly. Beyond that, a shop that's versed in these transmissions can build that same unit with upgraded parts from the aftermarket that solve many of the common pattern failures these transmissions are known for.

Very few that I would trust. Why take the risk when you can buy a new one from GM for $3400? with a warranty. Seems like an easy decision to me. But if you need a performance 6L80 these guys are the best. Always in Texas...LOL And they tell you what you get. For stock engine, this build is bullet proof.....$3800 rated to 550rwhp, 12 months warranty 12K miles as long as you don't exceed 800rwhp. LOL, Like anyone on this site has ever come close to 800. And if you are making that kind of power, you already know about these guys.

6L80 Level 2 Performance Transmission Rebuild - 5 Star Shop in TX

CDT Level 2 6L80 bench rebuild includes labor & all parts itemized. Ready to ship transmission back in 3-5 business days! 5-Star Houston transmission shop.

www.circledtrans.com

 

[gtrslngrchris]

I would be looking at nothing but a 10 speed myself at that pricing. My old boss and his new partner are putting them in everything they can and the swap for a 2015+ is all plug and play. I've seen 10 speeds out of wrecked trucks for 2k to 3k all day...

Home - Powertrain Swap Solutions

www.powertrainswapsolutions.com

 

[fasteddy]

I would be looking at nothing but a 10 speed myself at that pricing. My old boss and his new partner are putting them in everything they can and the swap for a 2015+ is all plug and play. I've seen 10 speeds out of wrecked trucks for 2k to 3k all day...

Home - Powertrain Swap Solutions

www.powertrainswapsolutions.com

That looks cool. Any documented references on that conversion. Everybody makes YouTube videos on successful swaps, right?. Any links for show and tell. And their kit is $3K? So I need a 10speed trans and the kit?