Need advice on an 07 yukon denali transmission its a 6l80e

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TheGrayArea

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Sisters denali with 6.2 6l80e awd got hot she kept driving -_- had to pick it up from her work, limp mode only 3rd gear, kill it shift to manual it goes through all 6 ok cool get it home pull the codes solenoids sticking on 3-6 if i member right. Fluid burnt metal in pan i realized it was outta my wheelhouse as i dont even have a slab im still very much a lay in the sand n get er done guy but i cant rebuild a trans yet so i call a local guy, he says trans needs rebuilt and transfer case needs new gears as theyre shot 4200 with labor, he has it 3 weeks and we get it back with this,"now any trans shop is gonna tell you they dont cover electrical and i dont either". Red flag spotted. He does give me a 3000 mile or 3 month warranty though so im feelin better, 3 days later she calls its back in limp mode, have her limp it home as trans temp read 175 ran the codes same one 3-6 solenoid malfunction, and now crankshaft position circut malfunction(replaced sensor like 100 miles ago but didnt do relearn as im not a millionaire) cleared em fired it up and she took it from san antonio to coprus no issues that i know of, sorry but thats where im at and shes 13000 into this truck now, what should i do? And did he just get the clutch pack and **** me on the other internals? Id say yes thats how the 5600 job cost 4200 but he seemed like a decent enough guy need some advice lol pic of said shitbox for reference
 

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petethepug

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It’s frustrating to guide someone through a major component repair and not be involved like it was your vehicle. Unless you’ve got the shop’s invoice you really don’t know what he did.

Can you take it for a spin and verify if somethings off? 07/08 Denali did have a weak spot in their trans but once that’s fixed it’s one of the longest lasting motor / trans combo of any of them because it lacks cylinder deactivation.


Denali has uprated trans cooling so hopefully he flushed the cooler when the trans was out. Black does get hot. We used that remote start quite a bit to pre cool the truck on sticky days.
 

Doubeleive

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Sisters denali with 6.2 6l80e awd got hot she kept driving -_- had to pick it up from her work, limp mode only 3rd gear, kill it shift to manual it goes through all 6 ok cool get it home pull the codes solenoids sticking on 3-6 if i member right. Fluid burnt metal in pan i realized it was outta my wheelhouse as i dont even have a slab im still very much a lay in the sand n get er done guy but i cant rebuild a trans yet so i call a local guy, he says trans needs rebuilt and transfer case needs new gears as theyre shot 4200 with labor, he has it 3 weeks and we get it back with this,"now any trans shop is gonna tell you they dont cover electrical and i dont either". Red flag spotted. He does give me a 3000 mile or 3 month warranty though so im feelin better, 3 days later she calls its back in limp mode, have her limp it home as trans temp read 175 ran the codes same one 3-6 solenoid malfunction, and now crankshaft position circut malfunction(replaced sensor like 100 miles ago but didnt do relearn as im not a millionaire) cleared em fired it up and she took it from san antonio to coprus no issues that i know of, sorry but thats where im at and shes 13000 into this truck now, what should i do? And did he just get the clutch pack and **** me on the other internals? Id say yes thats how the 5600 job cost 4200 but he seemed like a decent enough guy need some advice lol pic of said shitbox for reference
had mine rebuilt with all the known 6l80e fixes (that means extra welds where they break, non shrinking checkballs, etc) and a billet TC, extra clutches, new techm, new bell housing basically built for 500hp
$4200 out the door with a 3 year 100k warranty.
I am 3 years into it and around 40k miles, ZERO issue's and I don't baby it by any means
that was from the best shop in town, don't trust any old shop
 
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TheGrayArea

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I mean in a perfect world right I called around six shops where I'm at and least I was quoted was like 52 I think we just didn't have that kind of money had to go with what I could, so just the brag? No actual helpful input on the question? Or was your input that if i were to put a stage 2 on it it wouldn't be a problem I don't understand how any of that is supposed to help.

I guess if I could summarize do I need to buy solenoid packs and slap em in or is it just going to require a more in-depth teardown
 
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TheGrayArea

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It’s frustrating to guide someone through a major component repair and not be involved like it was your vehicle. Unless you’ve got the shop’s invoice you really don’t know what he did.

Can you take it for a spin and verify if somethings off? 07/08 Denali did have a weak spot in their trans but once that’s fixed it’s one of the longest lasting motor / trans combo of any of them because it lacks cylinder deactivation.


Denali has uprated trans cooling so hopefully he flushed the cooler when the trans was out. Black does get hot. We used that remote start quite a bit to pre cool the truck on sticky days.
She said it was shifting kind of funny still i think he didnt do check valves and shift solenoids to save a few bucks and theyre sticking cause of wear/chutch material gumming up but again im no trans expert but I thought it through pretty thoroughly and I consider myself not have a retard so a mildly confident in that assessment just figured I'd see if any of you guys can confirm my thought process there this is the 3rd 6l80f had to do with this year and I'm just really over these Transmissions piss poor build quality/tuning
 

Doubeleive

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I mean in a perfect world right I called around six shops where I'm at and least I was quoted was like 52 I think we just didn't have that kind of money had to go with what I could, so just the brag? No actual helpful input on the question? Or was your input that if i were to put a stage 2 on it it wouldn't be a problem I don't understand how any of that is supposed to help.

I guess if I could summarize do I need to buy solenoid packs and slap em in or is it just going to require a more in-depth teardown
ya I guess in a perfect world a qaulity rebuild is best,
I am not mr money when I had mine done I had the money set aside, in all reality most of the time when something happens I do not and my go to then is "used" in general this is usually the best bang for your buck. my reference was for the "price paid" it kind of sounds like you got taken for a ride
I would at least get under it and make sure the harness is on properly, fluid is full (check when hot, engine running). there is a tsb for the harness, pins come loose and it causes all kinds of issue's
if you are still in the 3k 3 month timeline I would at least swing by there and see what happens
 

swathdiver

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My guess is that the transmission's TECHM could have been rebuilt on your kitchen table for about $150 plus fluids and the transmission shop replaced the transmission but reused the old TECHM that was the real source of the problem anyway.

175 degrees is not hot, the computer goes into limp mode after 260 degrees.

As for the crank sensor, use GM OE parts only, same for the TECHM if you decide to replace the entire unit. A new one does require programming. Like I said, you can rebuild it on your kitchen table.


@NickTransmissions
 

NickTransmissions

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Sisters denali with 6.2 6l80e awd got hot she kept driving -_- had to pick it up from her work, limp mode only 3rd gear, kill it shift to manual it goes through all 6 ok cool get it home pull the codes solenoids sticking on 3-6 if i member right. Fluid burnt metal in pan i realized it was outta my wheelhouse as i dont even have a slab im still very much a lay in the sand n get er done guy but i cant rebuild a trans yet so i call a local guy, he says trans needs rebuilt and transfer case needs new gears as theyre shot 4200 with labor, he has it 3 weeks and we get it back with this,"now any trans shop is gonna tell you they dont cover electrical and i dont either". Red flag spotted. He does give me a 3000 mile or 3 month warranty though so im feelin better, 3 days later she calls its back in limp mode, have her limp it home as trans temp read 175 ran the codes same one 3-6 solenoid malfunction, and now crankshaft position circut malfunction(replaced sensor like 100 miles ago but didnt do relearn as im not a millionaire) cleared em fired it up and she took it from san antonio to coprus no issues that i know of, sorry but thats where im at and shes 13000 into this truck now, what should i do? And did he just get the clutch pack and **** me on the other internals? Id say yes thats how the 5600 job cost 4200 but he seemed like a decent enough guy need some advice lol pic of said shitbox for reference
Sounds like you took it to a flat rate shop. "flat rate" is an industry term for shops that literally do as little as possible to slap/patch a transmission back together for a much lower price; 30-90 days is the typical warranty. More than likely, frictions other then what were bad, were reused. Ive heard accounts of some shops literally washing frictions and bands in the parts washer to clean them. Lol!

Anyway, that thing has to come back out and be properly gone through. Given you had a hard parts failure initially, the TEHCM (which should always be replaced) should have definitely been tossed and a new OEM GM replacement installed; same with new internal mode switch, harness and speed sensor assembly. All new frictions, steels, bushings, rear sprag, seals in the direct drum, rear planet plus a Sonnax or Transgo hydraulic update kit, bonded pistons, piston return snap rings, HD parking rod assembly, reinforced welds on the 3-5-R drum, Sonnax billet 1-2-3-4 clutch apply piston, reman pump, Sonnax 4-5-6 piston kit w/extra friction and steel, 3-5-R apply ring, new converter with .070 thick high energy converter clutch and flanged hub/billet cover for HD, mild to moderate HP, etc...

$4200 for a transmission and transfer case rebuild is def flat rate territory, most of the above was likely not replaced. My 6L80s start at $4500.00 w/all of the above done.
 

j91z28d1

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man I feel your pain. hurts to put 5k in a something that goes for 7-10 around here. shame 130k is considered a good life for a tranny these days, but it seems to be.


it sounds like you're near San Antonio. if dude can't get it fixed, which sounds doubtful. Facebook market place search for motors Rmz. its a scrap lot with tons of gm stuff parting out. they seem to get about 1500$ for a used 6l80e, you might get lucky and with a new converter it last her a while. or at least long enough to get out of it and into something else.




good luck man
 
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