What did you do to your NNBS GMT900 Tahoe/Yukon Today?

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dkad260

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it wouldn't be the 1,2,3,4th G80 I have taken out of service before

My Envoy had the G80, but in an 8" rear, and when I had a similar issue it was replicated from a stop while already being in a small turn. I was on an off ramp, on a hill, turning to the left. Once I started up again, I would get a small "bump" in the rear and it wouldn't do it going straight, only applying a good load from a stop while turning, couldn't figure out what it was.

I ended up with a chipped spider gear and I just swapped the axle for a SS 9.5" as I have the 4:10 anyway.

I'm sure the few rainy exits from a parking lot lighting up a tire then the G80 locking contributed, and this was before I was aware of their delicate nature.
 

Geotrash

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he said it might be locking up the pads when i stop and then when it releases that is what I could be feeling, I don't think they are dragging per say because I would have smelled it and they would have found that easily.
I have installed larger Baer erradispeed rotors on the front and rear, and I could have installed the clips on the rear incorrectly a while ago though
Or it could be the spider gears winding up, but they don't want to condemn the rear end until they check the brakes
they are not charging for me diagnosing but I do have to be patient because it's being done as they have time.
I wonder if it could be a stuck parking brake back there. That could definitely cause some squat on launch.
 

Doubeleive

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I wonder if it could be a stuck parking brake back there. That could definitely cause some squat on launch.
I suppose anything is possible, but I have a feeling it may just be the rear end.
I remember when I was removing and putting the drive shaft in a couple times with the rear wheels off the ground spinning one wheel would only make the other wheel rotate the opposing direction "sometimes" I tried it couple times but wasn't sure if that was normal or not. still not sure, seemed odd.
 

Doug118

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$2800 was a little too good to be true. Noticed it had some blowby so I stuck a bore scope down the holes and found a broken piston. Not the end of the world, just annoying to have to fix it. Oh and this thing is FAST compared to my 8000lb suburban lolIMG_2006.jpegIMG_2019.jpeg
 

Geotrash

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$2800 was a little too good to be true. Noticed it had some blowby so I stuck a bore scope down the holes and found a broken piston. Not the end of the world, just annoying to have to fix it. Oh and this thing is FAST compared to my 8000lb suburban lolView attachment 406870View attachment 406872
Ouch. Looks like some scoring on the cylinder wall too. i’ll bet somebody ran that thing with 87 unleaded in it. Good opportunity to pull that engine, tear it down on the engine stand, and send it out for machining. You could get real serious about power mods for not much money, too.
 

Doug118

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Ouch. Looks like some scoring on the cylinder wall too. i’ll bet somebody ran that thing with 87 unleaded in it. Good opportunity to pull that engine, tear it down on the engine stand, and send it out for machining. You could get real serious about power mods for not much money, too.

I’m going to guess it was ran on 87 as well when gas prices were really high. I’m probably going to pull it and throw some stock pistons in it and put it back in. I thought about doing cam and valvesprings but I don’t want to go down a performance rabbit hole. I was fortunate enough for my wife to let me spend $30k on the stereo in the other truck. Don’t want to push my luck with trying to go fast in the “daily”
 

George B

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I wonder if it could be a stuck parking brake back there. That could definitely cause some squat on launch.
I was thinking something similar. Originally thought something goofy with hill start assist but the tech noted it was hard to turn the wheels on the rack. I didn’t mention it because if that but I thought it.
 

j91z28d1

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$2800 was a little too good to be true. Noticed it had some blowby so I stuck a bore scope down the holes and found a broken piston. Not the end of the world, just annoying to have to fix it. Oh and this thing is FAST compared to my 8000lb suburban lolView attachment 406870View attachment 406872


ouch.. I still feel like 2800 isn't to bad.
 

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