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