Full size kid hauler, GMT800 vs GMT900 vs Expedition EL/MAX or??

[Bebop]

Looking and digging, it seems that the 2007-2008 Yukon Denali came with the 6.2L motor that did NOT have AFM and has the advantage of the 6L80 transmission.
Any expensive downsides to them? It seems that the expensive concern on the GMT900s is the lifters for the AFM and that would eliminate those as a concern.

Aaron Z

No downfall.

Don't discard the later models for an AFM issue only. It's easy to drop new lifters/pushrods/valley cover plate and since you need to tune the trans, you can deactivate the AFM at the same time.

 

[Domer]

Looking and digging, it seems that the 2007-2008 Yukon Denali came with the 6.2L motor that did NOT have AFM and has the advantage of the 6L80 transmission.
Any expensive downsides to them? It seems that the expensive concern on the GMT900s is the lifters for the AFM and that would eliminate those as a concern.

Aaron Z

The 2500 yukon/burb never had afm/Dod. 6L series transmissions started in 08. At least in the 2500's.

 

[aczlan]

No downfall.

Don't discard the later models for an AFM issue only. It's easy to drop new lifters/pushrods/valley cover plate and since you need to tune the trans, you can deactivate the AFM at the same time.

Perhaps I am misunderstanding, as I understood it, the failure mode is the lifter failing (sticking collapsed?), rotating (?) and wiping out the cam.
That is reinforced by ads saying that their GMT900 needs a cam.
Is it a case where if you catch it early enough and do a delete it's fine?

Aaron Z

 

[aczlan]

The 2500 yukon/burb never had afm/Dod. 6L series transmissions started in 08. At least in the 2500's.

At the cost of 10-12MPG vs 14-16MPG?
The problem is that the 2005 Yukon that we are replacing has averaged about 12k miles per year and about 14MPG.
With fuel around $3.80 right now, that means we are spending around $3257/year on fuel.
Dropping to 12MPG would bump that to $3800 and 10MPG would be $4560/year.

If a AFM delete, cam and tuning on a 1500 GMT900 that then got 16MPG ran $2500, that would be paid back in fuel savings (vs a 2500 GMT900 at 12MPG) in 2.5 years.
Realistically, we have needed to tow something that was more than a 1500 is rated to tow 4-5 times in the 9 years that we have owned it, so towing capacity isn't important enough to sacrifice much milage on.
We had my inlaws 2002 F350 with a V10 for BDL worthy loads, looking for something to replace that with now as well.

Aaron Z

 

[Bebop]

At the cost of 10-12MPG vs 14-16MPG?
The problem is that the 2005 Yukon that we are replacing has averaged about 12k miles per year and about 14MPG.
With fuel around $3.80 right now, that means we are spending around $3257/year on fuel.
Dropping to 12MPG would bump that to $3800 and 10MPG would be $4560/year.

If a AFM delete, cam and tuning on a 1500 GMT900 that then got 16MPG ran $2500, that would be paid back in fuel savings (vs a 2500 GMT900 at 12MPG) in 2.5 years.
Realistically, we have needed to tow something that was more than a 1500 is rated to tow 4-5 times in the 9 years that we have owned it, so towing capacity isn't important enough to sacrifice much milage on.
We had my inlaws 2002 F350 with a V10 for BDL worthy loads, looking for something to replace that with now as well.

Aaron Z

Doesn't make any sense.

Buy a half ton a delete the AFM.

 

[aczlan]

No downfall.

Don't discard the later models for an AFM issue only. It's easy to drop new lifters/pushrods/valley cover plate and since you need to tune the trans, you can deactivate the AFM at the same time.

Looks like we may go down that road, found a 2012 with 170k miles for under $9k, has hail damage (hood looks like a golf ball, I presume the roof looks similar).
Seller claims to have owned it for 8 years.

Aaron Z