2014 Yukon XL - Gear Swap - 4wd

[EnigmaMan]

I am trying to find out the exact information I need for a front / rear gear swap and having found the following:

I remember when I did a gear swap in a Cutlass the differential supported up to a 3.23 gear but anything higher either required a ring gear spacer or a different differential to support 3.73 gears. Is this true for our rigs? According to Yukon Gear it says that there are Carrier breaks. As you can see the gears basically fit every single GM product known to man so finding the gears shouldn't be a problem!

Currently I have a 2014 Yukon XL 4wd (it is the classic style and not the newer trim upgrade that some of the newer 2014's have) and has the awful 3.08 gears. 1700RPM @ 80mph is a bit low IMO.



Yukon Gears for 2014+

GM 8.25 IFS Front 2010 & Newer
2010 & newer GM 8.25 IFS Aluminum front housing found in GM vehicles. Uses 8.25" reverse cut ring gear

• Ring Gear Diameter: 8.250
• Cover Bolts:
• Ring Gear Bolts: 10
• Spline Count: 28
• Dropout: True
• Pinion Support: False
• Carrier Breaks: 3.23 / 3.42
• Rear Suspension:
• Pinion Nut Size: 1-1/4

=====================================

GM 9.5" Rear, '14 & up
GM 9.5" rear with 12 bolt cover and 33 spline axles. 5.3L V8

• Ring Gear Diameter: 9.500
• Cover Bolts: 12
• Ring Gear Bolts: 12
• Spline Count: 33
• Dropout: False
• Pinion Support: False
• Carrier Breaks: 3.08 / 3.23
• Rear Suspension: Solid
• Pinion Nut Size: 32mm

 

[EnigmaMan]

Bump -
Will 3.73 Gears work with the stock carrier (that currently has 3.08 gears)???

 

[fiatdale]

I want to say that the stock carrier is good for 3.73 but not 4.10. Need someone else to confirm that though.

 

[EnigmaMan]

I hope I dont have to pick up a new set of differentials (carriers) - otherwise its going to be a set of ARB Air lockers on the front / rear of this bad boy :-D

 

[fiatdale]

I hope I DO have to pick up a new set of differentials (carriers) - its going to be a set of ARB Air lockers on the front / rear of this bad boy :-D

Fixed your post.

 

[EnigmaMan]

Anybody have any ideas or have done this gear swap?
Will the stock Carrier (Differential) support a change from 3.08 gears ===> 3.73 gears?
I am not sure what the break point is for this.

Thanks!

 

[EnigmaMan]

Ok did some research and looks like to upgrade past the 3.08 gears to 3.73 requires a new carrier for the rear but the front is requiring a full new axle???

Would a rear gear spacer allow for a me to do this swap successfully?

Surprised I have not gotten much feedback on a performance upgrade like this???

 

[EnigmaMan]

I found some more information that will help others understand what carrier brakes are and why they are necessary / important.

GM created a carrier brake at 3.08 and requires a thicker gear to compensate for the smaller pinion or a different carrier deck height ( new differential)

Defining Differential Carrier Breaks
Differential carriers are designed to accommodate a range of Ring & Pinion gear ratios for the various tire sizes and vehicle applications associated with them. As the numerical ratio of a gear set increases, the diameter of the pinion gear gets smaller. The reduced size of the pinion gear requires an increasingly thicker ring gear to keep the gear surfaces meshed properly.

It becomes more economical at some point to change the carrier deck height, so that the ring gear is thinner, and requires less material.