2008 Tahoe Z71 Rebuild - DOD Failure - DOD/AFM Delete & Performance Upgrades (201k miles)

[SmokesMagee]

Hey Tahoe community,

Sharing my rebuild project after experiencing:
- DOD failure at 201k miles on cylinder 4.
- Transmission failure at 192k (sun shell welded to rear planet on highway, due to internal cooling malfunction)

Going for a full rebuild with DOD/VVT delete and reliability upgrades. Here's my parts list:

Engine Internals:
- AMS Racing Stage 2-212/218; .480/.480 DOD/AFM Delete Kit
- King Armor Coated Main Bearings
- King Armor Coated Rod Bearings
- AMS Armor Coated Cam Bearings
- HD Timing Chain (GM #12646386)

Valvetrain:
- Harland Sharp 1.7 Ratio Roller Rockers (Adjustable)
- PAC 1.307 Ovate Beehive Springs
- Stock retainers/locks (confirmed compatible)

Sealing:
- AMS Racing Lower Gasket Set
- Considering upgrade to ARP head bolts (+$95)

Additional Plans:
- Full dual exhaust upgrade
- Complete DOD/VVT delete
- Fresh rebuild with upgraded components

Looking for feedback on this parts combination and any recommendations before I start the build. Anyone running a similar setup?

I bought this Tahoe with 181k miles on it, and have owed on it since. Whoever owned this before me beat the piss out of it and starved it of oil. Cam has heat marks ..

Vehicle specs:
2008 Tahoe
5.3L Gen IV
4l60E
201k miles
Edit; Z71 package.

Here are some pictures too

(transmission magnet, ended up finding very low mileage one instead of rebuild)

 

[swathdiver]

- AMS Racing Stage 2-212/218; .480/.480 DOD/AFM Delete Kit

What made you pick this camshaft?

 

[SmokesMagee]

What made you pick this camshaft?

Nothing specifically made me choose this camshaft.
I want a stage 2 for durability. I am open to suggestions as I am still contemplating the cam. Perhaps a Truck Norris. But I'm not 100% on my cam selection.

Here is reference;

Performance AFM DOD Delete Kit w/ Brian Tooley "No Springs Required" Truck Camshaft for Gen IV 5.3L Chevrolet GMC Truck SUV

This kit includes everything needed to delete AFM/DOD (Active Fuel Management) from 2006-2009 GM Gen IV 5.3L engines. This kit will work with 2010-later engines, with the use of an LS2 style front cover (VVT Deletion). Kit Includes:-Your choice of BTR "No Springs Required" Truck Camshaft -Your...

www.amsracing.net

 

[swathdiver]

Nothing specifically made me choose this camshaft.
I want a stage 2 for durability. I am open to suggestions as I am still contemplating the cam. Perhaps a Truck Norris. But I'm not 100% on my cam selection.

Here is reference;

Performance AFM DOD Delete Kit w/ Brian Tooley "No Springs Required" Truck Camshaft for Gen IV 5.3L Chevrolet GMC Truck SUV

This kit includes everything needed to delete AFM/DOD (Active Fuel Management) from 2006-2009 GM Gen IV 5.3L engines. This kit will work with 2010-later engines, with the use of an LS2 style front cover (VVT Deletion). Kit Includes:-Your choice of BTR "No Springs Required" Truck Camshaft -Your...

www.amsracing.net

Well, do they equate stages now with strength? I thought some manufacturers offered camshafts in different materials with the same profile?

A camshaft with more than 210 degree duration in a 5.3 gives up bottom end torque for top end power. The only exception to this is the BTR Truck Torque camshaft because of the tight lobe separation angle.

 

[Marky Dissod]

Stages / Levels are a dumb way to explain, so they'll stick around, maybe even become more popular ...

Biggest reason why I'm uninterested in buying a cam is all the dyno charts start at 3000RpM or higher.
What if I don't want a high-stall torque converter? What if my engine spends most of its time UNDER 3000RpM?

Despite costs, this is why I think an LQ4 or other 6.0L, or 4.10, get more bang for the buck than camming a 5.3L.
ANYWAY

You should select your cam based on where your engine spends most of its time, likely UNDER 4000RpM.
Choose correctly, you will barely notice any MpG penalty, and the engine will be stronger / more fun.
Choose poorly, the MpG penalty will be in your face, and the engine will feel weak before it comes on stronger.

 

[SmokesMagee]

Well, do they equate stages now with strength? I thought some manufacturers offered camshafts in different materials with the same profile?

No, you're correct.

A camshaft with more than 210 degree duration in a 5.3 gives up bottom end torque for top end power. The only exception to this is the BTR Truck Torque camshaft because of the tight lobe separation angle.

I did not know this.
I shall look into the BTR Truck Torque cam.
What I'm looking for in a cam;
Something not too extreme while still maintaining daily driving (is not going to be daily driver, as I have a daily for fuel economy, but will be casual driver, as well as taken to the track)(and backup for main commute) looking to give it some real power without putting forced induction.
My goal is to keep the truck till the day I die.

I am no mechanic, my brother is ASE Master certified and don't want to help me because "I get paid to work on lifts" I have no idea what I'm doing, I'm a monkey with a wrench, but I generally figure it out, as I put a lot of time into research and also things just bolt together.. my uncle builds engines and is willing to help me put this together, I just have to get the parts.

I'm looking for some real input from others that know more about this. Any input is appreciated.


I have also put a new rear end in this truck, with the help of my brother, as the rear end was damn near going out in this. Had no fluid when I pulled the cover as it all spun out the axle shaft.

Stages / Levels are a dumb way to explain, so they'll stick around, maybe even become more popular ...

Biggest reason why I'm uninterested in buying a cam is all the dyno charts start at 3000RpM or higher.
What if I don't want a high-stall torque converter? What if my engine spends most of its time UNDER 3000RpM?

Despite costs, this is why I think an LQ4 or other 6.0L, or 4.10, get more bang for the buck than camming a 5.3L.
ANYWAY

You should select your cam based on where your engine spends most of its time, likely UNDER 4000RpM.
Choose correctly, you will barely notice any MpG penalty, and the engine will be stronger / more fun.
Choose poorly, the MpG penalty will be in your face, and the engine will feel weak before it comes on stronger.

Thank you for this input.. even on the highway it's only at 1500-2000 then going around the city is about the same. If you're towing I suppose rpm would be different. This is actually really valuable feedback. Thank you.
Reading this really sets apart why daily drivers are so far from being "high performance".

And to top it off. I've also put all new front end suspension components on. Detroit Axle. And yes, I replaced the knuckle, old one was bent and worn down. New brakes (minus caliper), and shoes.

 

[swathdiver]

I've also put all new front end suspension components on. Detroit Axle...

Be very careful with Detroit Axle components, they are the bottom of the barrel as far as quality goes.

Did you keep the same gear ratio?

 

[SmokesMagee]

Be very careful with Detroit Axle components, they are the bottom of the barrel as far as quality goes.

Did you keep the same gear ratio?

Yes, same gear ratio.. and yeah... After buying them I instantly regretted my decision when I started putting parts on. But it desperately desperately needed it

 

[Marky Dissod]

... even on the highway it's only at 1500-2000, then going around the city is about the same.
If you're towing I suppose RpM would be different. This is actually really valuable feedback. Thank you.
Reading this really sets apart why daily drivers are so far from being "high performance".

If you're towing, or playing hard, 4.10 or 4.30, especially if the tires are taller than GM OE, or the wheels are heavier.
More assertive gearing helps prevent lugging the engine at too low an RPM, and protects the transmission too.
The Tow / Haul button makes the most of whatever axle gear GM compromised it with,
avoiding unnecessary / early upshifts, and downshifting to protect the engine & transmission.

All that said, there's a reason why the Tow / Haul rating of a vehicle improves with more assertive axle gears.
In the real world, more axle gear gets better city MpG, might get slightly worse highway MpG unladen.
But the heavier you tow, or the harder you play, 4.10 or 4.30.

 

[SmokesMagee]

If you're towing, or playing hard, 4.10 or 4.30, especially if the tires are taller than GM OE, or the wheels are heavier.
More assertive gearing helps prevent lugging the engine at too low an RPM, and protects the transmission too.
The Tow / Haul button makes the most of whatever axle gear GM compromised it with,
avoiding unnecessary / early upshifts, and downshifting to protect the engine & transmission.

All that said, there's a reason why the Tow / Haul rating of a vehicle improves with more assertive axle gears.
In the real world, more axle gear gets better city MpG, might get slightly worse highway MpG unladen.
But the heavier you tow, or the harder you play, 4.10 or 4.30.

With this, I am definitely going to invest in a separate transmission cooler.
I appreciate the feedback. It really helps with building this truck.

 

[Marky Dissod]

... definitely going to invest in a separate transmission cooler ...

Every 4L60E behind a V8 that does not live in a permanent winter NEEDS an air-to-ATF cooler.
Every 4L60E behind a V8 that only lives in a permanent winter NEEDS a coolant-to-ATF heat exchanger (it's not a cooler, gottdamnt).

If the vehicle works or plays hard, upgrade the air-to-ATF cooler, followed by the radiator.
Don't forget: sooner or later, you WILL need to rebuild the 4L60E, with upgrades.

 

[SmokesMagee]

Don't forget: sooner or later, you WILL need to rebuild the 4L60E, with upgrades.

I definitely know this. Just getting a few miles out of it before I do. Transfer case, and front dif too.

If the vehicle works or plays hard, upgrade the air-to-ATF cooler, followed by the radiator.

Radiator is cracked, it's repairable but a different cooler is in mind for transmission, and radiator.
Any insights as to selecting the right part for the job?
Edit; I know about panels, that's about it.

I didn't know there was a two types. I'm from Michigan. So it's cold 6 months of the year
But not that cold. So I suppose I'd most likely never see coolant-to-atf

 

[Marky Dissod]

In Michigan, you definitely need your ATF warmed every winter regardless.
For the summer, bypass the ATF warmer, especially if the vehicle is working or playing hard.

 

[j91z28d1]

In Michigan, you definitely need your ATF warmed every winter regardless.
For the summer, bypass the ATF warmer, especially if the vehicle is working or playing hard.

I know you're not going to agree but this has been thoroughly explored on this site and others. do not bypass the radiator end tank cooler at any time. while I might add some heat on a cold day, the tranny Temps when used hard will always always he hotter than the cold side of the radiator end tank. you always run fluid thru there first and then put to any add on cooler.

at some point with a larger add on cooler guys have see it raise the coolent temp because of blocked airflow. they find laying it flat down low has helped. foggy here even has a fan in his.


there's a 30 plus long thread here where the guys towing big rigs work thru to the best combo over a few years of towing. this thread should be a sticky bit it's worth a read if you can find it.


again, my opinion. at no time should you bypass the radiator fluid cooler, tranny or oil. if you need added cooling, loop in front mounts after there.

 

[Geotrash]

I know you're not going to agree but this has been thoroughly explored on this site and others. do not bypass the radiator end tank cooler at any time. while I might add some heat on a cold day, the tranny Temps when used hard will always always he hotter than the cold side of the radiator end tank. you always run fluid thru there first and then put to any add on cooler.

at some point with a larger add on cooler guys have see it raise the coolent temp because of blocked airflow. they find laying it flat down low has helped. foggy here even has a fan in his.


there's a 30 plus long thread here where the guys towing big rigs work thru to the best combo over a few years of towing. this thread should be a sticky bit it's worth a read if you can find it.


again, my opinion. at no time should you bypass the radiator fluid cooler, tranny or oil. if you need added cooling, loop in front mounts after there.

Bon apetit!

Keeping coolant and transmission temps under control when towing in the summer heat

Hi All, the 2012 XL Denali is a towing beast, but after the cam upgrade, new HD torque converter, and adding the Tru-Cool 40K in front of the radiator, the engine itself is running warm now that we're getting into spring. Hauled our 6500 lb camper down to Virginia Beach this weekend in 83º...

www.tahoeyukonforum.com

 

[Foxy]

That's a great set up. I would say 100% use the ARP head bolts and resurface the heads before putting them back on. A side note but it's not a must do I would recommend porting the heads also. But you'll definitely want to take them to a head shop and have them resurfaced and pressure tested before installing them back on.

 

[mikez71]

Every 4L60E behind a V8 that only lives in a permanent winter NEEDS a coolant-to-ATF heat exchanger (it's not a cooler, gottdamnt).

Ya know, I've been thinking about that, wouldn't every cooler be a heat exchanger? There's no way to add cool without heating something up. You dump ice on it, but now you're warming the ice..

I know, if it was not heating any autoparts or auto fluids, its being transferred to the outside environment. Cooler...

 

[Marky Dissod]

Ya know, I've been thinking about that, wouldn't every cooler be a heat exchanger?
There's no way to add cool without heating something up. You dump ice on it, but now you're warming the ice..
I know, if it was not heating any autoparts or auto fluids, its being transferred to the outside environment. Cooler ...

OK, every cooler is a heat exchanger - but every heat exchanger is NOT a cooler.
Radiator sheds its heat to the ATF, and the air - but the motor oil heat exchanger sheds its heat to the coolant.
Radiator is a coolant cooler, though.

 

[MD-Wood]

Mevotech makes some nice suspension parts that are real upgrades to GM parts.
Also as far as rear end look into Truetracks, they are nice tough limited slips that lock up solid. They use a different oil though, be aware of that.
Lastly, look into Tick Performance for cams, they have a nice line of staged cams and complete kits.
I run a stage one towing cam in my daily driver silverado, with dod afm delete, oil pump upgrade, timing set upgrade, link bar lifter upgrade(not happy with the noise from them), trunnion and spring upgrades comp cam pushrods and shorty headers

 

[Geotrash]

Mevotech makes some nice suspension parts that are real upgrades to GM parts.
Also as far as rear end look into Truetracks, they are nice tough limited slips that lock up solid. They use a different oil though, be aware of that.
Lastly, look into Tick Performance for cams, they have a nice line of staged cams and complete kits.
I run a stage one towing cam in my daily driver silverado, with dod afm delete, oil pump upgrade, timing set upgrade, link bar lifter upgrade(not happy with the noise from them), trunnion and spring upgrades comp cam pushrods and shorty headers

Not to hijack the thread, but I'd read similar comments about the link bar lifters, so I ended up going with Chevrolet Performance lifters when I did my cam swap/dod delete in my '12. Sorry yours are noisy, but I'm grateful for the datapoint.

I'm also considering going to Mevotech (their expensive line) control arms and tie rods for my '07. I put Moog parts on it when I bought it back in 2018, but it's only seen 50K since then and the dust boots on the lower ball joints are already shot and they're starting to chatter when I turn the wheel on a chilly day. That's the last time I'll put Moog on anything again. Good to see a vote of confidence for the Mevotech stuff.