Originally posted by diver:
I appreciate the response but will the $10 fix work? lol and how would it the tc shift then and scotty mentioned removing the interlock pill? what is that and how do you do it and how does it then shift to 2 wheel low?
You are asking why modification of the stock unit will work. I am the wrong guy, the modifier would be a better person to answer this question.
The transfer case shifts via the vacuum shift motor on the Mode Control Rod on the NP229 case.
In the case of chevelleguy, his NP229 Viscous Coupler was "shot" so attempting to place the vehicle in 4-Wheel Hi was problematic, as the Viscous Coupler inside of the NP229 Transfer Case no longer contained the Silicon fluid to act as the "liquid clutch" in order to apply power to BOTH front and rear driveshafts at the same time.
So, he essentially bolted the plates together, so that they always transfer torque from the transmission to both the front and rear dirveshafts at the same time. Therefore there is no longer any possible way to put it in 2-Wheel drive with this particular modification. However it probably does not matter much, as long as you keep the front left axle disconnected via a shift motor (not all vehicles have this "Feature"), then you essentially have 4-Wheel Hi set.
Inside of the Transfer Case there is some sort of interlock, Scotty is better informed on this subject than I am.
Again, it hardly matters, as the plates inside the transfer case have been bolted together, they have essantially put the vehicle in all wheel drive.
Only those applications where the front left axle is disconnected from the front differential need to be concerned (I think!) about the interlock inside the transfer case.
Something about being able to drive at 75 MPH in 4-Wheel Lo or something to that affect.
Murphey seez...If it ain't broke, you can't fix it