Awesome. I'll be sure and check both here and in your build thread for any updates

I did some more reading on zr2usa.com and found a thread about fulltime engagement of the front axle, many of the replies stated that it's the same as doing the Bravada shaft swap. After that I looked into the Bravada shaft and apparently the front differential is always engaged in the Bravada. Their autotrack AWD system has a clutch and different transfer case to switch between 2HI and 4HI as it senses slip.

It seems though that many people with the 233 transfer case have swapped in parts from the Bravada so that their front axle is always engaged. There are also a few different posts in the threads below where people locked the actuator cable so that the diff was engaged full time.

Both the actuator lock and bravada shaft seem to allow the truck to run in 2HI (with front diff engaged) until you shift the transfer case (manually or via the push button on the dash)

http://www.zr2usa.com/mboard/index.php?showtopic=45582 <full time engaged front diff

http://www.zr2usa.com/mboard/index.php?showtopic=43818 <info about the bravada shaft swap


This weekend, I'll try and engage the front diff while the tcase is in 2HI and see if its actually powering all four wheels.

 

It`s finished, check my build thread...

 

The transfer case is always engaged, either hi or lo.(or in neutral) The 4-wheel part happens when the front differential is engaged. This is usually vacuum controlled, but whether you use vacuum, cable, or electric actuator makes no difference. In fact, a cable controll would allow you the added luxury and maneuverability of hi or lo in 2-wheel mode. Sweet! A long hood-release-type cable would work nicely with no worries about vacuum lines, delicate actuator diaphragms, etc. Good luck.

tjack

 

Perhaps this is the case on some trucks but on Blazers and S10's the tcase and differential can both be engaged or disengaged independently. There are several Blazer owners that have swapped in parts from the Bravada axle so that the front axle/differential/driveshaft are always engaged. The only shifting required is the tcase which you can leave with the stock motor or shift manually like Steinbruchsoldat did and I am planning to do.

Hitting the 4HI button in the dash actuates the encoder motor on the transfer case putting it into 4wheel instead of 2wheel AND it engages the front diff. While driving around in 2HI, your driveshaft is stationary and is engaged with neither.

EDIT: I am referring to the threebutton 233 transfer case

 

Not entirely true. In all of the two speed transfer cases used in the s-series, when in 2HI, the transfer case is not coupled to the front driveshaft. Only the NV236 has some semblance of torque transfer to the front driveshaft when in 2HI due to the preloaded clutch it uses.

You are correct in stating that without the front axle engaged, there is no torque transfer to the front wheels.

 

2 HI rear only engaged
4 HI fronthalf of trans case comes into play PLUS that vac switch to activate front axle.
4 LO somewhat the same actions as 4HI, but in an UNDERDRIVE mode.
So, locking the front axle "should not" cause too much if any dry pavement bind aslong as in 2HI in transfercase.

 

Way to bump an old thread reburtonjr! 'Locking' the front axle in 2wd should cause absolutely no binding because the front differential is an OPEN differential. Think of it like a normal GU6 rear axle- it surely doesn't bind around corners.

I'm in the middle of doing the bravada front axle swap as we speak... Over the years I've had nothing but problems with the old vac system. I've replaced the t-case vacuum switch 4 times, the vacuum actuator twice, numerous vacuum hoses (some from rubbing front driveshaft), the shift cable once, and replaced the shift fork+ spring once. Never again!