Can a OLV 2" Lift contribute to X-fer case binding?

[blinkibus]

Hi folks,

2004 Chevy Astro AWD, 2" OLV lift, little bit of T-Bar crank, otherwise stock


To make a short story long:

Had transfer case replace a couple months ago with a reman unit.
This was a long and painful process involving a non-existent warranty, an unscrupulous dealer, and 3 different replacement units and a surprising amount of money for something that was supposed to be covered under warranty.

This van was smooth as silk and tight before the lift/transfer case work began.

Before the T-case replacement I had installed and OLV 2" lift, but had some driveline vibration, and had shackles in middle holes which alleviated the vibration, and had not yet messed with the torsion bars.. The van was driven only around town and for maybe 100 miles like this and while I could get some shims and resolve the vibration problem, which I did.

During this time it seemed like I was noticing some binding at the t-case, as in "oops left it in 4 wheel drive on dry pavement" sort of feel. As I continued to work on the van in short sessions and got the rear end up with shims into the "tallest" hole in the shackles and then did a little T-bar crank to level it out, and I put a few more miles on the vehicle, the binding became worse and worse, to the point where I had to swing wide on every turn even just during normal driving to prevent any binding and if a 90 degree turn in a parking lot was unavoidable, well there was chirping of tires and loud groaning noises and all sorts of really bad things happening.

When it got to this point I took it straight back to the mechanic who had installed the transfer case, who I have been working with for years, and he told me that the lift was causing the problem, and that I needed to Unlift the van now before I cause any more serious damage. These guys build hot-rods and custom bikes and have chopped pickups and stuff and I wouldn't expect them to give me a hard time about a lifted van, but it sure seems like they are. The Boss man at the shop who apparently is the only one who clearly understands why the lift would cause transfer case issues is out of town until Monday, I have an appointment to speak with him then. I have been in communication with OLV who have been helpful.

I removed the front driveshaft today so the pressure is off, but man am I getting tired of this!
Any Advice.

OLV's assures me that the body lift doesn't affect the drivetrain geometry except at the rear pinion so there should be no connection between transfer case issues and the installation of the lift.

I checked the fluid level in the t-case. Good
I checked for loose connectors all around that area or frayed wires, ground issues, all clean.
This van has 144k miles, but it is clean and tight otherwise, and I am just dying to get on to other things.
Front and rear differentials are clean, no seepage.
The shims I installed to changed the pinion angle are 4 degree shims, I have heard that 2 degree shims might have been better, can the increased pinion angle somehow cause a systemic inbalance that is causing binding at the transfer case?

Is my trusty mechanic trying to get out of warranty-ing the transfer case by blaming it on the lift?

Thanks everybody!

[MountainManJoe]

Did you fill it with the blue synthetic GM Autotrac II fluid? I went through a similar warranty nightmare before I figured out how to fix it myself. Apparently, nobody bothers to check TSB's.

[blinkibus]

Yeah the fluid is blue and the mechanic who put it in said there was a bulletin on some sort of additive that was $35 a pint or something like that. I'm exaggerating, but I think the fluid is right.

So I removed the front drive shaft on my 2004 awd astro, and the van doesn't roll and feels like it's in park, is there a message in there?

Thanks!

[1Gary]

USE THE E-BRAKE.It will not hold in park with the driveshaft removed.

[MountainManJoe]

There shouldn't be any additive. Just the GM oil, and around here it costs $5.

[Logan]

Speed sensors in transfer case. They don't go bad that often though. Apparently they had a repair kit. On my 2002 it included new sensors and and new plug. The plug was solidered and heat shrunk. My van had 320,000 before they were replaced. I've also got a 2 inch lift. My shop installed some used sensors and off I went. I was getting the same binding feeling and tires barking. The AWD light would come on too so I would just pull the ATC fuse under the hood till the repair could be done. Hope this helps.....