10th generation Chevrolet Suburban questions

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want to upgrade from 2008 Tahoe to 2010-2012 Suburban LTZ (leather, 4WD), which years to avoid?
I am pretty familiar with the 2008 Tahoe issues, like leaking fuel pump due to rust. It has been mostly reliable but some things drove me nuts, like the cruise control that hasn't worked in the last 5 years.

When was the old 4L60E transmission swapped for something newer, and is this newer 8-speed any better?

When was the cylinder deactivation feature no longer available, or do all 10th gen have it?
 
The 4L60E was dropped in favor of the 6L80E in 2009, Every 2010-2012 1500 Suburban I've ever seen had a AFM 5.3L.

The 8L90E wasn't available 'til a few years into the 11th generation.....It's a piece of crap anyway.

Th 6L80E can have Torque Converter Clutch issues which generally fills the unit with Aluminum & Steel debris before it can be caught & repaired in time. Requiring a full rebuild & replacing the trans coolers. The 11th gen 6L80E is even more prone to this failure because changes to the calibration.

'10, '11, & '12 are all the same in my opinion.....There was some updates to alleviate AFM related oil consumption during the 2010 production run.

I'm not a fan of AFM, Some trucks go a long time without issues, Others seem to be riddled with AFM issues. The more 8 to 4 cylinder transitions occur......The more likely the Locking Pins in the AFM Lifters will wear & eventually stick in the collapsed position causing a misfire.

I won't normally repair the AFM on these......It gets a full Hardware Delete or the customer can take it elsewhere. Though I will unlock a collapsed lifter & turn the AFM off in the calibration, But there is NO warranty!

The cruise control issue on your 2008 could be a brake switch issue. Common on all GMT900 trucks.
 
The 4L60E was dropped in favor of the 6L80E in 2009, Every 2010-2012 1500 Suburban I've ever seen had a AFM 5.3L.

The 8L90E wasn't available 'til a few years into the 11th generation.....It's a piece of crap anyway.

Th 6L80E can have Torque Converter Clutch issues which generally fills the unit with Aluminum & Steel debris before it can be caught & repaired in time. Requiring a full rebuild & replacing the trans coolers. The 11th gen 6L80E is even more prone to this failure because changes to the calibration.

'10, '11, & '12 are all the same in my opinion.....There was some updates to alleviate AFM related oil consumption during the 2010 production run.

I'm not a fan of AFM, Some trucks go a long time without issues, Others seem to be riddled with AFM issues. The more 8 to 4 cylinder transitions occur......The more likely the Locking Pins in the AFM Lifters will wear & eventually stick in the collapsed position causing a misfire.

I won't normally repair the AFM on these......It gets a full Hardware Delete or the customer can take it elsewhere. Though I will unlock a collapsed lifter & turn the AFM off in the calibration, But there is NO warranty!

The cruise control issue on your 2008 could be a brake switch issue. Common on all GMT900 trucks.
Of course under normal times GM sells over 40,000 units a month of Silverado/Sierra combines. And of course the Suburban is the number one seller in its class. The 8 speed problems were mostly cured by the introduction of different fluid. And yes-the six speed autos while not the most refined do see failure in usually higher mile trucks. GM has a TSB out that changes the thermostat, and thus the operating temperature so it runs cooler-which helps.

For some unusual reason used Suburbans are instantly sold when they are listed. But hey they people that buy them probably are not mechanics.

I'm not a mechanic but have owned three and have had zero issues. ALL with the 6 speeds and AFM-so there is that.
 
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2010-2014 suburbans are the same style as your 2008 Tahoe. Afm is an issue in all of them even with the upgrades gm did to try and fix it.
 
2010-2014 suburbans are the same style as your 2008 Tahoe. Afm is an issue in all of them even with the upgrades gm did to try and fix it.
No AFM is not an issue with all of them. A very, very small minority have issues.
 
Cline- my work truck is a 2019 K1500 5.3, with 100k km on it, always serviced and has one trans service on it. 6 spd I think, the trans pisses me off as I catch it flat footed- doesn't seem to know where it is or where it's going- maybe 20% of the time. My driving style is easy- until this happens. Common?
 
AFM is not an issue, I know how to easily turn it off.
Transmissions issues are a much bigger issue. I'v seen a 2011 Suburban for sale, the seller said he had total transmissions failure - meaning the torque converter.

Maybe I should stay with 2007-2008 Suburbans?
 
Also I am thinking same years Yukon XL Denali with the 6.2L.

ALL 6.2L GMT900 trucks come with a 6L80E, Though the early ones (L92/L9H) didn't have AFM & don't suffer as much from Converter failure, But early 6L80E's do have their own set of issues, Like the 1234/35R Drum cracking & Stator Sealing Ring leakage.
 
Cline- my work truck is a 2019 K1500 5.3, with 100k km on it, always serviced and has one trans service on it. 6 spd I think, the trans pisses me off as I catch it flat footed- doesn't seem to know where it is or where it's going- maybe 20% of the time. My driving style is easy- until this happens. Common?

I haven't done any tuning on 2019+ trucks yet, The ECM can't be accessed without having it manually unlocked, Then it costs $400 to license it. Where 2016 & down costs $100 without having to send the ECM out to be unlocked.
2017 & up costs $200 if equipped with a 6L80E.
8L90E equipped trucks require the TCM to be sent off & unlocked which is an additional $200.

However....Most of the (Shift Feel/Shift Timing) issues with 6L80E units IS in the Tuning/Calibration, The TCC will lock up half way through 1st gear & wants to stay locked. I tune them to lock only in 4th/5th/6th, Or 5th/6th....Then adjust the Upshifts/Downshifts to suit the vehicle/final drive ratio.
 
ALL 6.2L GMT900 trucks come with a 6L80E, Though the early ones (L92/L9H) didn't have AFM & don't suffer as much from Converter failure, But early 6L80E's do have their own set of issues, Like the 1234/35R Drum cracking & Stator Sealing Ring leakage.

Does that mean it's wise to stay away from a 6L80E vehicle?
 
In this market...Might be wise to not buy a vehicle at all ;)

When built & tuned correctly....The 6L80E is a fantastic unit! But to pay top dollar for a 150K-200K truck that could be on the cusp of failure OR has been bandaided with a Reman Converter is foolish.

GMT900 4L60E's have a known expensive issue that nobody talks about....The ISS Sensor is not replaceable without removing the Unit, Converter, & Front Pump. I've seen people get burned over this because the sensor can be intermittent & not show up during a test drive.

If the DTC's have been cleared within 500-1000 miles....I consider it a red flag on just about any vehicle.
 
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