Let's Talk GMT900 DriveShafts !

[Foggy]

From what I understand, It's just a speed/ critical speed issue.
So if you don't plan on cruising at 95 mph+ alot, the factory one is fine
Of course new 1350 solid spicer type u joints and a balance job is always
a good idea. Our rigs are all 11+ years old now !!!

 

[j91z28d1]

only thing I can add is just for curiosity sake. my drive shift measures about 40 1/4in from middle of u joint cap to middle cap. I believe you're supposed to measure from flange to flange. but I'm not pulling it out for that haha.

2011 hybrid yukon with the 2ml70 tranny and 4x4 transfer case bolted on the back. what looks to be a 3in Dia aluminum one.

 

[Marky Dissod]

From what I understand, it's just a speed / critical speed issue.
So if you don't plan on cruising at 95MpH+ alot, the factory one is fine ...

GM OE for the PPV would be better than fine - and it'd still be 'factory'!

 

[Foggy]

To update some info: I talked (finally) in person to a reputable driveshaft
shop that does custom/racing/hotrod shafts.
I described what I've got now and what would be needed to upgrade or
prevent a future issue.
My current driveshaft is approx 55" from UJoint center to UJoint Center and
approx 60" from trans case face to differential face. It's 3.5" in diameter and
is STEEL.
The shop I spoke with said there should be no issues even at speed with
the short of a driveshaft that is 3.5" diameter Steel.
So maybe there were some changes in the GMT900 platform as the years
progressed.. IDK.
But I'm just going to replace my Ujoints with the Spicer solids - 1350- series
and have it balanced

 

[swathdiver]

The RWD Suburbans, Yukon XLs, Avalanches and Escalade ESVs and EXTs all use a 1 piece aluminum driveshaft.

The 4x4 Suburbans, Yukon XLs, Avalanches and Escalade ESVs and EXTs all use a 1 piece tapered steel driveshaft.

All use 1355 universal joints and yokes for the rear shaft.

The front shafts are steel and use 1344 universal joints and yokes. The shape and diameter of the tubing between my 2009s front driveshaft and the ones in my 2012 and 2013 pickups are different.

The front and rear driveshafts ought not to exceed 5,000 rpms, that's shaft rpms, not engine, lest they destroy themselves.

The GMT900 and K2 pickups with the 1 piece aluminum driveshaft are notorious for twisting them to pieces when they hit the magic speed of 112 mph.

This is the data I've gathered over the years and it has not been peer reviewed:



These comments generally exclude the 2007-2008 SUVs as I believe they were still using the previous generation's components. Can't recollect with certainty.

 

[Foggy]

Thanks for the extra info swathdiver
The UJoints I purchased and am going to use on my rear driveshaft
are a 1350 series U Joint. IDK if the 1355 you mentioned is the same or not.
I don't think I've ever used a 1355 series

 

[Marky Dissod]

These comments generally exclude the 2007-2008 SUVs, as ...
they were still using the previous generation's components. Can't recollect with certainty.

The previous generation's component of concern is the 4L60E.
The vehicles with 6L80E obviously used different shafts.

 

[swathdiver]

Thanks for the extra info swathdiver
The UJoints I purchased and am going to use on my rear driveshaft
are a 1350 series U Joint. IDK if the 1355 you mentioned is the same or not.
I don't think I've ever used a 1355 series

The AAM 1355s are different but the Spicer 1350s work fine when thinner snap rings/clips are used.