GMT800 vs GMT900. Which to buy?

[DefineLife42]

Hello all,

I'm in the market to upgrade my current daily, a 05 Highlander with either a 800 or 900 Yukon Denali/SLT though unsure which would be better overall for reliability and dependability. While I'm not scared to buy a higher mileage one with good service records and am aware that typically with higher mileage ones I'll be looking at expensive repairs (suspension, timing chain, control arms, etc) I'm unsure which generation would be better. One issue that I'll run into with either vehicle would be northeastern rusting issues and also navigating it through NY streets but I'll adapt. I do drive around 12-14k miles a year and would love a big cruiser on the highway. I am somewhat mechanically inclined and can wrench on some basic things.

GMT800: Definitely the more basic of the two generations though the suspect nature of the 4L65 leaves much to be desired of. Typically more higher mileage and more likely to run across beaten up examples than relatively clean. That being said, I do have a soft spot for this generation. One pro of this generation would be not having AFM.

GMT900: Much more luxury focus with so much more amenities than the 800 (backup cam, heated/ventilated seats, higher quality interior). The 6L80 isn't that bad (?) at least compared to the 4L65 which isn't saying much. But the big boogy man of this generation is the introduction of AFM which GM ruined a perfectly bulletproof, stout and workhorse engine to a lifter waiting to collapse (damn you EPA). Could find cleaner examples though but at a much higher premium. While I am aware there are tunes/chips that disable the AFM, I have heard the lifters do have a potential to fail.

Thoughts/opinions/advice?

 

[S33k3r]

I suggest the 800s, as they seem to be the last generation before GMs bankruptcy, when things apparently went down in terms of quality. Do check me though --I'm delivering this via memory from reading up on them.

Secondly, I suggest looking outside the rustbelt for a non-rusty example.

FB Marketplace, Craigslist, and/or OfferUp for examples. Also, the cost outside outside of New York is likely low enough that you can not only afford to buy a good example, but you can likely cover the airfare there and pay for your trip back.

 

[DefineLife42]

I suggest the 800s, as they seem to be the last generation before GMs bankruptcy, when things apparently went down in terms of quality. Do check me though --I'm delivering this via memory from reading up on them.

Secondly, I suggest looking outside the rustbelt for a non-rusty example.

FB Marketplace, Craigslist, and/or OfferUp for examples. Also, the cost outside outside of New York is likely low enough that you can not only afford to buy a good example, but you can likely cover the airfare there and pay for your trip back.

Yeah I was considering going out of state for a non-rusty example or an exceptional frame around the tri-state area.

I mean I can find 04-06 Denalis relatively in good condition for around $5k which in a market like this is a steal.

 

[S33k3r]

Don't forget about Escalades! You can likely find some right-priced examples of those, too.

 

[Doubeleive]

I would say 2010-2014, turn off the afm I don't think it is that much to worry about to be honest.
interior is less likely to get ratted out, get a black interior because under the paint they are all black anyway so when the paint wears off or gets scratched guess what? you get to look at black worn spots. the only thing you ever see worn out on these is the ac control buttons, steering wheel trim pieces, maybe the center console pleather. all easily replaceable.
and yes the dash cracks, that can be covered with a dashmat or if you desire they make a cap.
I loved my 800 had it for almost 15 years but I wouldn't go back
Wife is still driving a 05 but i'm going to move her up as soon as I find "the one" maybe a escalade. Prices seem to be getting much more reasonable lately even seeing some reasonable K2's out there

 

[DefineLife42]

I would say 2010-2014, turn off the afm I don't think it is that much to worry about to be honest.
interior is less likely to get ratted out, get a black interior because under the paint they are all black anyway so when the paint wears off or gets scratched guess what? you get to look at black worn spots. the only thing you ever see worn out on these is the ac control buttons, steering wheel trim pieces, maybe the center console pleather. all easily replaceable.
and yes the dash cracks, that can be covered with a dashmat or if you desire they make a cap.
I loved my 800 had it for almost 15 years but I wouldn't go back
Wife is still driving a 05 but i'm going to move her up as soon as I find "the one" maybe a escalade. Prices seem to be getting much more reasonable lately even seeing some reasonable K2's out there

The interiors on the 900 chassis are really nice all things considered. Good dash materials, and functional as well. Yeah I know the HVAC controls tend to be worn down more quickly than anything. I looked at the Escalades of both generation, they look like but I do like the subtleties of the Yukon Denali.

 

[avalonandl]

I like the 900's

Had both...

 

[Airman68]

I would say 2010-2014, turn off the afm I don't think it is that much to worry about to be honest.
interior is less likely to get ratted out, get a black interior because under the paint they are all black anyway so when the paint wears off or gets scratched guess what? you get to look at black worn spots. the only thing you ever see worn out on these is the ac control buttons, steering wheel trim pieces, maybe the center console pleather. all easily replaceable.
and yes the dash cracks, that can be covered with a dashmat or if you desire they make a cap.
I loved my 800 had it for almost 15 years but I wouldn't go back
Wife is still driving a 05 but i'm going to move her up as soon as I find "the one" maybe a escalade. Prices seem to be getting much more reasonable lately even seeing some reasonable K2's out there

I agree with this. Just nicer overall, more modern. Definitely want the 6 spd tranny. I have the 4spd (2008) which is ok but I suspect the 6spd will get better mileage and tow much better. However you cant go wrong with a nice 800, just not much to worry about with them, very reliable.

 

[B-train]

I've had both as well and am partial to the 2007-09 years with a 6.2L. The 6 speed is nice, and when serviced properly it performs well. Heck, most higher mileage ones have already had it replaced either under warranty or otherwise.

The newer LS motors with VVT (especially 6.2L) are animals and sound good. Decent fuel economy, comfy seats, and good handling overall in my book. I actually prefer my 2008 to my 2017 in seat comfort and engine burble.

As stated the climate buttons suck and get worn off, and the stupid dash cracks from a non-salt area sucks, but it beats dealing with rust.

Use FB, auto trader (private seller), etc and look out west (I use Sacramento as a hub) and down south (Norman, OK as a hub). Had good luck both places. Good questions/research up front, then a one-way ticket, and a fun joyride home. Think of it as an adventure. Just be sure to buy some Murphy repellent when you head out - basic hand tools, some fluids, etc if you are handy just in case.

Happy searching!

 

[DefineLife42]

I've had both as well and am partial to the 2007-09 years with a 6.2L. The 6 speed is nice, and when serviced properly it performs well. Heck, most higher mileage ones have already had it replaced either under warranty or otherwise.

The newer LS motors with VVT (especially 6.2L) are animals and sound good. Decent fuel economy, comfy seats, and good handling overall in my book. I actually prefer my 2008 to my 2017 in seat comfort and engine burble.

As stated the climate buttons suck and get worn off, and the stupid dash cracks from a non-salt area sucks, but it beats dealing with rust.

Use FB, auto trader (private seller), etc and look out west (I use Sacramento as a hub) and down south (Norman, OK as a hub). Had good luck both places. Good questions/research up front, then a one-way ticket, and a fun joyride home. Think of it as an adventure. Just be sure to buy some Murphy repellent when you head out - basic hand tools, some fluids, etc if you are handy just in case.

Happy searching!

Yeah it wouldn't be unheard of to hear a transmission or two replaced with either generation. I mean I'm getting a massive beefy full-sized SUV with a beefy V8, I expect gas mileages to equal that. I'd rather deal with a cracked dash than having swiss cheese holes in my frame.

I thought about taking a small trip somewhere down south/midwest to get a clean framed one. Yeah I have some basic hand tools, gonna bring a aftermarket head unit with me to swap out in like a Walmart parking lot so driving back is a lot easier.

 

[Doubeleive]

Yeah it wouldn't be unheard of to hear a transmission or two replaced with either generation. I mean I'm getting a massive beefy full-sized SUV with a beefy V8, I expect gas mileages to equal that. I'd rather deal with a cracked dash than having swiss cheese holes in my frame.

I thought about taking a small trip somewhere down south/midwest to get a clean framed one. Yeah I have some basic hand tools, gonna bring a aftermarket head unit with me to swap out in like a Walmart parking lot so driving back is a lot easier.

I flew to vegas and bought mine and drove it home 7 hours, it was middle of the night so I just pulled into a mcdonalds at 4am and slept in the back for a couple hours and drove it the rest of the way home, lots of rust free ones on the west coast but always check the car fax to see where it has been. I wouldn't touch one from anywhere on the east coast, maybe florida.... and plenty in Texas seem to be priced fair

 

[B-train]

Yeah it wouldn't be unheard of to hear a transmission or two replaced with either generation. I mean I'm getting a massive beefy full-sized SUV with a beefy V8, I expect gas mileages to equal that. I'd rather deal with a cracked dash than having swiss cheese holes in my frame.

I thought about taking a small trip somewhere down south/midwest to get a clean framed one. Yeah I have some basic hand tools, gonna bring a aftermarket head unit with me to swap out in like a Walmart parking lot so driving back is a lot easier.

PM me if you are interested in a sale. I'm toying with selling my 2008 Denali. It came from CA. It's in WI now, but rarely gets driven due to having a company truck. I'm thinking of getting a pickup and am looking at possibilities.

If interested, reach out and I can give you more info. Well maintained and in good shape.

 

[okfoz]

I have a 2007 Tahoe LTZ, 280,000 miles, burns no oil, original 4 speed Transmission (never rebuilt) The only recurring issue I have is the catalytic convertor likes to fail, and no one can diagnose why. I had the rear axle rebuilt at around 200K due to a funny noise. Beyond that it has been a great vehicle.

 

[Marky Dissod]

I have a 2007 Tahoe LTZ, 280,000 miles, burns no oil, original 4L60E (never rebuilt).

Congratulations. That said, best be prepared; sooner or later ...

The only recurring issue I have is the catalytic convertor likes to fail, and no one can diagnose why.

Which one? Or both?

 

[91RS]

GMT-900 for sure. #1 reason because of rack and pinion steering. The 800s feel worn out and sloppy even if you replace everything. The 900 also has just enough features (if you get a Denali or Escalade) to not feel like you’re driving an old car but without the $90k price tag of a new car with all this cool stuff they made you think you had to have that won’t work by the time the warranty expires because it’s outdated and can’t be upgraded.

 

[okfoz]

As mentioned before, I have 280K on my 2007 Tahoe LTZ. In January my wife and me went to Hawaii, and we rented a newer Tahoe GMT900. It was a nice truck had some newer features, but it did not have anything that made me want one. And, with only 60,000 miles on it the truck ran like garbage. We went with Friends and he got the Suburban, and he said his was the same way, ran like garbage. At that point I decided that I would just nurse my 07 as long as possible.

 

[okfoz]

Congratulations. That said, best be prepared; sooner or later ...
Which one? Or both?

The Catalytic Convertor, is almost always the Right Side (Bank 2), one time out of the 5 it has failed was bank 1, every other time is Bank 2. It lasted about 70,000 miles this last time, I think this last failure was my own fault because I took so long to replace Cyl 8 spark plug. I have replaced all of the injectors at 250,000 to diagnose a problem with a fuel leakdown, which causes it to start somewhat hard after it sits for several hours. Easy to bypass, just turn key on wait 3 seconds then it fires right up.

 

[strutaeng]

I'll vote for GMT 800, but I'm partial to them. I have a 1999 Silverado RCSB 2wd that bought back in college. Got really good use of it. I bought an 06 Suburban 2500 2wd because I needed more room to drop my kids off school in the morning but hanging on to the 99. The suburban is pretty high mileage, but runs good. I also have an 04 suburban 4x4 that I bought as a project. In the GMT 800 to me it boils down to 4L60e vs 4L80e. I really like the 4L80e. Even learned how to overhaul them myself last year. I just wish the 6 speeds were more durable. I mean, many are. And rebuild kits are so darn expensive. I have a 6 speed in a 2020 Express Van my wife drives.

Interestingly, my 99 Silverado has rack and pinion. I just replaced it because it was leaking badly, and basically rebuilt the entire front end. On it's third time rack and pinion at 270k. The 06 is steering box. I've never understood why some trucks have R&P vs steering box. I thought on the 99-02 1500 trucks it was a 2wd vs 4x4 thing?

I didn't realize the GMT 900s had R&P. That's on all of them? Even the 4x4? I don't think I've been inside a GMT 900 now that think about it.

 

[Doubeleive]

I'll vote for GMT 800, but I'm partial to them. I have a 1999 Silverado RCSB 2wd that bought back in college. Got really good use of it. I bought an 06 Suburban 2500 2wd because I needed more room to drop my kids off school in the morning but hanging on to the 99. The suburban is pretty high mileage, but runs good. I also have an 04 suburban 4x4 that I bought as a project. In the GMT 800 to me it boils down to 4L60e vs 4L80e. I really like the 4L80e. Even learned how to overhaul them myself last year. I just wish the 6 speeds were more durable. I mean, many are. And rebuild kits are so darn expensive. I have a 6 speed in a 2020 Express Van my wife drives.

Interestingly, my 99 Silverado has rack and pinion. I just replaced it because it was leaking badly, and basically rebuilt the entire front end. On it's third time rack and pinion at 270k. The 06 is steering box. I've never understood why some trucks have R&P vs steering box. I thought on the 99-02 1500 trucks it was a 2wd vs 4x4 thing?

I didn't realize the GMT 900s had R&P. That's on all of them? Even the 4x4? I don't think I've been inside a GMT 900 now that think about it.

all the 1500's yes, and then the 15+ are all electric, no power steering pump or pulley but they add a vacuum pump where the alternator normally is and moved the alternator over to the right. then on the 21+ it's all screwy with the coolant reservoir on the drivers side and everything is moved back more, seats are higher, pillars are thick and you have a sun visor sized view out the back window..

 

[Marky Dissod]

I get why feature creatures might prefer the GMT900 over the GMT800.
I even miss the GMT900's rack&pinion steering.
IFF I lived where road & traffic allowed for more driving fun, I MIGHT prefer a GMT900 over a GMT800.

Since road & traffic where I live conspire against driving fun, and I VASTLY prefer Lean Cruise over either having V4mode, and/or spending money to get rid of V4mode,
I vote GMT800, whether 4L60E or 4L80E.