2012 Yukon Denali 6L80 Issues/Advice

[Fubar0715]

The same online store has OE Y Pipe and cats for just under $800, about a months depreciation on a new rig.

perhaps even less time on a TOP O' LINE model....

 

[Foggy]

Sonnax Zip Kit and parts are the best.. They fix all the original flaws.. The biggest
is in the tiny clutch inside the torque converter...
Replacing these torque converters is almost preventative maint ...
There are better aftermarket converters that have a large clutch apply area...
And don't just judge work or price on warranty....
If it's a ****** trans, it will show itself in a couple of months... IF its' a quality
build and you take care of it, it'll outlast the truck...
BTW: service your auto trans (filter and fluid) every 20-25K.. 50K is way too long,
these things are almost 6000 lbs... trannys are working hard all the time

 

[swathdiver]

? Same price.

Are you talking about the core charge?

Yessir!

 

[wsteele]

Yessir!

Got it. So I guess they really want the old one's back.

 

[Pointer 21]

I really appreciate ALL the information this forum has provided. I was going to drop off the Yukon on Tuesday but Houston had the storm come through leaving many of us without power.

Collectively it seems that everyone agrees that a rebuild with the following should be a solid transmission: Sonnax Clutches
Precision Torque Convertor
AC Delco for solenoids etc.

A post for another thread but I believe I'll be doing Cat work right after this as I've heard that bad cats hurt the transmission/motor (hoping this doesn't eat my lunch) along with the rest of the squeeks under my front end that I have yet to dive into.

 

[Seapro]

Good Morning Gurus! I'm new to the board but have been using it as a resource (Great One at that).

Quick Facts:

-2012 GMC Yukon Denali 152,000K miles
-Bought Brand New
- 0 problems to date

ISSSUE: I was running fine last week, felt something a LITTLE sketchy when shifting out of first (at a stop light).
Next day was driving on the freeway (AND ZOOOMMMM) RPMS hit 3,000 + and I'm doing 30 mph until I can get to the closest town.
After I set for awhile I was able to drive with little problems; HOWEVER, the engine light came on AND has sense turned off.

My question: I've been to one mechanic who had good reviews. He didn't even look at it and just said "yeah, I know what's going on $3300 for aftermarket parts and a rebuilt transmission".
I gather he knows his stuff; however, how do I know what's actually gone in that transmission? Seems to me like a Torque Converter would be necessary and whatever else. Also, he would be using Sonnax aftermarket parts? **Opinions here?***

Is this just a "fix it once and replace everything while you're in there approach" and is it advised?

I believe I will be needing work done to my Catalytic convertor and likely some suspension repairs in the near future.

Trying to figure out my total cost of ownership or if its time to abandon ship and move onto the next problem vehicle.

Any advice is appreciated - My apologies for the long post.

Hi, just some input from my experience with a transmission problem. The transmission, according to my mechanic, is controlled by a module. I would have a shop or mechanic who kind of specializes in GM's put it on their scanners and give you a report on the issue. I believe even though your check engine light went out the system still holds it so you can see what that was all about. In my case I had the module reprogrammed and it has been running fine this year. Just something else you might want to check.

 

[Pointer 21]

I'm afraid you might be onto something here....I got the vehicle back yesterday (still licking my wounds from the complete rebuild). He did put a rear main seal in for free BUT I'm still leaking oil (in the pan), need suspension work and to replace both sway bar links.

The codes I'm throwing are as follows:

B1600:Mirror Motor Vertical Circuit
B3782: Air flow Control 10
Circuit Open or Short
B0433: Temperature Control
3 Feedback Circuit Open

All of this was according to him and I have a shop looking at it this AM.


Any advice from anyone on how I should proceed?

 

[wsteele]

I'm afraid you might be onto something here....I got the vehicle back yesterday (still licking my wounds from the complete rebuild). He did put a rear main seal in for free BUT I'm still leaking oil (in the pan), need suspension work and to replace both sway bar links.

The codes I'm throwing are as follows:

B1600:Mirror Motor Vertical Circuit
B3782: Air flow Control 10
Circuit Open or Short
B0433: Temperature Control
3 Feedback Circuit Open

All of this was according to him and I have a shop looking at it this AM.


Any advice from anyone on how I should proceed?

The codes above (other than th mirror) are HVAC codes and none are related to your transmission (or TCM). They are all BCM codes.

 

[Pointer 21]

I guess that's good news? My AC isn't blowing cold air on the driver side (I thought it was an actuator door).

The other shop just called and quoted me out on my rear main seal. The transmission shop replaced the rear main seal but nothing else (the gaskets etc). so I'm still leaking oil.
My transmission guy is strictly transmission and won't touch the other stuff normally, but I talked him into the rear main seal while he was in there. They're saying it ALL needs to be replaced including my suspension work.

I'm at a loss with all these repairs and can't tell whos giving me the shaft (if anyone).

Is it just as labor intensive to replace the gaskets around the oil pan as the rear main seal? In other words without him replacing the gaskets was that basically all for nothing (since I'm still leaking oil)?

BAD Week so far!!

 

[wsteele]

I guess that's good news? My AC isn't blowing cold air on the driver side (I thought it was an actuator door).

The other shop just called and quoted me out on my rear main seal. The transmission shop replaced the rear main seal but nothing else (the gaskets etc). so I'm still leaking oil.
My transmission guy is strictly transmission and won't touch the other stuff normally, but I talked him into the rear main seal while he was in there. They're saying it ALL needs to be replaced including my suspension work.

I'm at a loss with all these repairs and can't tell whos giving me the shaft (if anyone).

Is it just as labor intensive to replace the gaskets around the oil pan as the rear main seal? In other words without him replacing the gaskets was that basically all for nothing (since I'm still leaking oil)?

BAD Week so far!!

There are a number of common leak points under there. The oil pan gasket is a pretty big job and likely should be left to professionals unless you are pretty handy. Check out YouTube if you want to know all most of the common leak points on your engine.

The AC stuff won't cause your transmission (or any other drivetrain) issues, so given the change of seasons coming, maybe address the oil leaks first.

 

[Pointer 21]

There are a number of common leak points under there. The oil pan gasket is a pretty big job and likely should be left to professionals unless you are pretty handy. Check out YouTube if you want to know all most of the common leak points on your engine.

The AC stuff won't cause your transmission (or any other drivetrain) issues, so given the change of seasons coming, maybe address the oil leaks first.

We're probably getting into another thread; however, getting hit with ~$7,000 in repairs has me thinking I may have looked into a new vehicle. That said the suspension issues are BAD:

Lower Ball Joint
Sway Bar Link
Front complete strut assembly
New CV Assembly

The shop was saying to address the Struts above everything bc my wheels are about to fall off LITERALLY. My thinking is to at least do something fun to it (maybe a level or something) if I'm going to drive around in this 2012. I'm at a loss and going broke here...

 

[wsteele]

We're probably getting into another thread; however, getting hit with ~$7,000 in repairs has me thinking I may have looked into a new vehicle. That said the suspension issues are BAD:

Lower Ball Joint
Sway Bar Link
Front complete strut assembly
New CV Assembly

The shop was saying to address the Struts above everything bc my wheels are about to fall off LITERALLY. My thinking is to at least do something fun to it (maybe a level or something) if I'm going to drive around in this 2012. I'm at a loss and going broke here...

Not sure I am going to make you feel better, but with a new truck, you know for certain you are losing 10K a year in depreciation, every year, for quite a while. That's a lot of ball joints...

 

[Pointer 21]

Not sure I am going to make you feel better, but with a new truck, you know for certain you are losing 10K a year in depreciation, every year, for quite a while. That's a lot of ball joints...

HA HA - You sir are 100% correct! Now I just need to start figuring out the rest of the unforeseeable(s)!!

 

[Geotrash]

We're probably getting into another thread; however, getting hit with ~$7,000 in repairs has me thinking I may have looked into a new vehicle. That said the suspension issues are BAD:

Lower Ball Joint
Sway Bar Link
Front complete strut assembly
New CV Assembly

The shop was saying to address the Struts above everything bc my wheels are about to fall off LITERALLY. My thinking is to at least do something fun to it (maybe a level or something) if I'm going to drive around in this 2012. I'm at a loss and going broke here...

I did all of these components on my 2007 just after I bought it a few years ago. Took me a Saturday with the only special tools required being an impact wrench, a 1/2" drive torque wrench, and an industrial strength pickle fork to get the ball joint separated from the knuckle. You can rent everything but the impact wrench from your local parts store. I replaced everything with all Moog parts from Rock Auto, but everywhere stocks the parts for these things. I didn't bother separating the ball joints from the control arms and just replaced the control arms with the new ball joints pre-installed. You're probably looking at $700 in parts and you'll be good to go for another 200K.

And, if you want to check how bad it is for yourself, lift each front corner with a jack and give the wheels a healthy rock up/down. A loose ball joint will be obvious. You can also inspect the dust boots on the ball joints and CV joints for damage. If they pass these simple tests, find a new mechanic.

 

[Pointer 21]

I did all of these components on my 2007 just after I bought it a few years ago. Took me a Saturday with the only special tools required being an impact wrench, a 1/2" drive torque wrench, and an industrial strength pickle fork to get the ball joint separated from the knuckle. You can rent everything but the impact wrench from your local parts store. I replaced everything with all Moog parts from Rock Auto, but everywhere stocks the parts for these things. I didn't bother separating the ball joints from the control arms and just replaced the control arms with the new ball joints pre-installed. You're probably looking at $700 in parts and you'll be good to go for another 200K.

And, if you want to check how bad it is for yourself, lift each front corner with a jack and give the wheels a healthy rock up/down. A loose ball joint will be obvious. You can also inspect the dust boots on the ball joints and CV joints for damage. If they pass these simple tests, find a new mechanic.

 

[Pointer 21]

You must be reading my mind because I was thinking the same and they have me at: $783 (parts)
$600 (labor)

I did look under there myself and it looks pretty sketchy...The work definitely needs to be done.

 

[swathdiver]

We're probably getting into another thread; however, getting hit with ~$7,000 in repairs has me thinking I may have looked into a new vehicle. That said the suspension issues are BAD:

Lower Ball Joint
Sway Bar Link
Front complete strut assembly
New CV Assembly

The shop was saying to address the Struts above everything bc my wheels are about to fall off LITERALLY. My thinking is to at least do something fun to it (maybe a level or something) if I'm going to drive around in this 2012. I'm at a loss and going broke here...

The lower ball joint can be replaced on the car for about $80, or the whole arm can be replaced for between $50 and $150 depending on the quality of the parts used.

Sway bar links are about $40 for OE or less for aftermarket.

Struts assemblies are cheap and most report that they don't ride nice or last very long. OE struts last a long long time and cost about $600-700 for the pair to build from scratch.

CV shafts last forever if cared for, don't know the going rate for GM but am about to replace a Kia's for $50 for a new one!

 

[Pointer 21]

Regarding the rear main seal. If my transmission guy replaced it and it's still leaking due to the gasket not being replaced. Was that job all for nothing? In other words is the location of the pan gasket just as much as labor intensive as the rear main seal meaning it's a pain to get to on an AWD?

My tranny guy wanted nothing to do with the oil leak...simply a favor while he was in the transmission (didn't charge me).

 

[wsteele]

Regarding the rear main seal. If my transmission guy replaced it and it's still leaking due to the gasket not being replaced. Was that job all for nothing? In other words is the location of the pan gasket just as much as labor intensive as the rear main seal meaning it's a pain to get to on an AWD?

My tranny guy wanted nothing to do with the oil leak...simply a favor while he was in the transmission (didn't charge me).

The rear main seal and the pan gasket are two completely unrelated seals. t is a good idea to replace the rear main seal when removing/reinstalling the transmission as you need to take the transmission out to replace the rear main seal and the act of replacing the rear main seal is quite simple, once you have the transmission out.

The pan gasket is not affected by removing/reinstalling the transmission, so it makes sense that a transmission specialist would not want to replace a leaky oil pan gasket (if that was what was leaking). Replacing the pan gasket is pretty involved, maybe 2-3 hours of labor for an expert. For someone handy who owns a decent tool chest maybe 5 hours, maybe a couple of days, with lots of bad words thrown in, for a newbie.

 

[Pointer 21]

Yeah, I'm not messing with the oil issues myself; I don't particularly trust this shop but they're right across the street from me and I was curious what they had to say, in which they did say my rear main seal was bad (that's odd bc I had it replaced last week) LOL.

My trans guy said he thought it would be easier to get to those other leaking gaskets saving me some cash. They're saying it's the same amount of work regardless...