2010 Yukon axle swap

[Rabbler]

Hi all

First off I did do some searching on the forum and think I know the answer but just looking for some reassurance.

I recently acquired a really nice 2010 Yukon. It currently has the 5.3 and 6L80 trans with 3:08 GU4 G80 axles. I'm primarily using it to tow my 19' Lund ProV and double axle trailer. It does a pretty decent job fully loaded with 3-4 people and full gear but you definitely know its back there. Pretty flat ground where I live.
I recently found a good deal on a set of complete axles from an 07 Yukon with 3:42 GU6 axles. Would these be a direct bolt in? Any significant changes or parts to swap over between 07 and 2010?

Also I understand computer adjustments would be required for the new ratio is something a dealer or good transmission shop could do or do you actually need custom HP tuning or similar?

For those that have re geared from 3:08 to 3:42 did you notice a significant change in performance, engine/trans temp or fuel economy? Good or bad

Not looking to tow anything huge but I do have an enclosed 16' cargo trailer and possibly tow a midsize travel trailer in the future.

I do plan to add an external trans cooler in the spring.

Thanks everyone

 

[West 1]

I just rebuilt both my 3.42 axles on my 08 Denali. If I had known I was rebuilding both I would have switched to 3.73 gears with the 6L80. Even 3.42 gears are too tall, I wish I had the 3.73's.

Yes the 07 axles should bolt right in to your 2010. Around 2010 I think GM went to a heavier rear axle? verify the U join part numbers are the same for both years.

 

[swathdiver]

Since 2007 was a first year model, make sure the axle has the electrical connections at each end (JL4). Other than that, it's a direct bolt in affair.

There's a big difference in performance between 3.08 gears and 3.42s, especially when towing and running heavy. I eventually went from 3.42s to 3.73s and she tows even better!

Yes, you ought to get a tune and have your speedometer corrected and your shift points adjusted to do it right. A BlackBear tune will extend the life of the transmission and improve its performance too. GM dealers don't do this kind of work and most shops are ill equipped for it.

Not to send you down a rabbit hole, the RWD Escalades and Denalis came with a 14-bolt axle that is a direct fit and all were 3.42 geared. Much stronger for towing.

If your donor axles come from a Chevy, make sure it has the G80 Locker if that's important to you. I wouldn't leave home without it!

 

[Rabbler]

Since 2007 was a first year model, make sure the axle has the electrical connections at each end (JL4). Other than that, it's a direct bolt in affair.

There's a big difference in performance between 3.08 gears and 3.42s, especially when towing and running heavy. I eventually went from 3.42s to 3.73s and she tows even better!

Yes, you ought to get a tune and have your speedometer corrected and your shift points adjusted to do it right. A BlackBear tune will extend the life of the transmission and improve its performance too. GM dealers don't do this kind of work and most shops are ill equipped for it.

Not to send you down a rabbit hole, the RWD Escalades and Denalis came with a 14-bolt axle that is a direct fit and all were 3.42 geared. Much stronger for towing.

If your donor axles come from a Chevy, make sure it has the G80 Locker if that's important to you. I wouldn't leave home without it!

Good tip about the electrical connection, thanks. Is that something you can swap over or is it a different housing?

 

[Miami-Dade]

@Rabbler Moved you here from 2015+section

 

[swathdiver]

Good tip about the electrical connection, thanks. Is that something you can swap over or is it a different housing?

Don't know for sure. My axles have raised bosses for the sensor to screw into and internally, the axle tube diameter is stepped to seat the reluctor wheels.



See the white bushing for the parking brake cable? Just to the right and behind is the wheel speed sensor and screw securing it to the axle. The wire is dropping off to the right. In this view the axle is upside down and we're looking at the driver's side.

 

[Foggy]

I would suggest just rebuilding your existing axles and upgrading them
to the 3.73 gear ratios
You'd be going from 15 year old axles to 18 year old axles by doing a wholesale
swap out.
You could even upgrade your rear with better parts that won't leave you stranded
like the G80 can when towing !!