2007 Yukon. Lost 1st and reverse gears in transmission. Replacement options?

[dictum]

What years tranny will fit in my 2007 GMC Yukon? 6.2L Denali. This is the non-XL version.

I understand it's the old 4L60E, what years? I heard 4L80E could fit, is it possible?

 

[Marky Dissod]

Unless you plan on doing even more 'Heavy Duty' stuff than you do now,
either have your 4L60E beefcaked to 4L70-spec,
or find and order the above, and maybe send yours in as a core.

 

[petethepug]

Ask and you shall Receive. The YXL Denali (all 07/08 & 09-14 AWD) got the 4L60. Same goes for the Escalade. The pick up trucks pretty much follow the same but not 150% sure on variances. 4L60e / 4L80e is the same as 4L60 /4L80. The only exception is that there’s and EARLY 4L60 related by name only that may confuse some.

Unfortunately, as stated in the video, the 4L80 is bigger, longer & heavier than the 4L60. View it and see the road you’ll need to travel on.

If you have the time, it’s worth it. Another resource is the 2015 & 2015.5 Escalade. 2015 got the 4L60 & 2015.5 got the 4L80 on their 6.2L. That means you’ve got two examples with a working model of both on the same chassis.

 

[dictum]

I am looking at this 2008 Yukon Denali XL parts car, the seller claims it comes with 4L80, how is that possible?
is it a rare 3/4 ton Yukon? In which case it comes with 6.0L not 6.2L

 

[dictum]

Unless you plan on doing even more 'Heavy Duty' stuff than you do now,
either have your 4L60E beefcaked to 4L70-spec,
or find and order the above, and maybe send yours in as a core.

Understood
I think I will stick to my generation and focus on 4L60E.
So it's 2007-2013 GMC and Escalade and Silverado with 6.2L, correct?

 

[Marky Dissod]

WAITWAITWAITWAITWAIT a sec ...
What is your transmission RPO code?
Pop open the glovebox & check for
'MYC'
If NOT 'MYC', let us know what it is ...

 

[mikeyss]

What am I missing here, there has never been a 6.2 4 speed combo. All 6.2's were mated to the 6 speed 6L80 in the SUV/Trucks.

 

[Geotrash]

What am I missing here, there has never been a 6.2 4 speed combo. All 6.2's were mated to the 6 speed 6L80 in the SUV/Trucks.

+1. If it's an '07 Yukon Denali then it has the 6L80. Yes, Im sure.

 

[NickTransmissions]

Understood
I think I will stick to my generation and focus on 4L60E.
So it's 2007-2013 GMC and Escalade and Silverado with 6.2L, correct?

You should have the 6L80 and what appears to be a no-movement condition. Have you replaced or rebuilt the trans as of yet?

 

[dictum]

I have not done anything to it yet. Just looking for the part.
So I have the 6L80E transmission. Interesting. Then why did it fail if it's more robust? I never towed with it.

 

[Marky Dissod]

I have not done anything to it yet. Just looking for the part.
So I have the 6L80E. Interesting. Then why did it fail if it's more robust?

You say you have not yet done anything to it.
Does that include not changing the ATF? If so, how many miles has it gone without an ATF change?

 

[Geotrash]

I have not done anything to it yet. Just looking for the part.
So I have the 6L80E transmission. Interesting. Then why did it fail if it's more robust? I never towed with it.

The '07 has an early version of the 6L80 before it was in the field long enough for weaknesses in the design or manufacturing process to show up. In Nick's 6L80 thread, he details what those are. And many of them have little to do with how it's used. Its design is quite stout in terms of power handling capabilities, but there are problems like the TC, and one of the clutch drums that has weak welds, and check balls in the valve body that can show up as problems. Honestly though, 17 years out of a transmission ain't bad.

 

[dictum]

Strangely, the problem went away after being present for a few weeks. No grinding when going in or out of the first or reverse.

could it be something else, not the transmission? Like the AWD component in it? Should I change the oil in it?

 

[NickTransmissions]

Strangely, the problem went away after being present for a few weeks. No grinding when going in or out of the first or reverse.

could it be something else, not the transmission? Like the AWD component in it? Should I change the oil in it?

It could be or it may have been something else not associated with the transmission or t-case entirely. Generally, once the transmission starts grinding, it's not long before it stops working correctly all togther. Obviously, those things dont fix themselves (as much as we wish they did)....If you havent done a t case fluid change, id go ahead with it - drain the fluid in a catch pan so you can inspect it...stir it slowly with a telescope magnet so any larger metal pieces get caught on it if present in the fluid.

Otherwise keep an eye/ear out for it...

 

[dictum]

What fluid do I put in the transfer case?

 

[donjetman]

What fluid do I put in the transfer case?

Dexron6 or equivalent in my AWD BW4485