If you reach down and pull the shifter into 2wd, it is in 2wd. There is a mechanical linkage and if it were not coming out, you would not move the shifter. As stated, on the 02 and up trucks there is no CAD so when you pull the shifter out, it is out. On CAD trucks you will pull the T-case out but if the CAD actually has enough force to unlock, I don't know. Once the T-case is taken out of gear there is no power sent to the front via the driveshaft but the question is, does the mass of the driveshaft create enough drag to cause there to be a significant load on the CAD collar itself, not letting it disengage with just the force of the vaccum actuator? I think not but JMO.

 

Good Point...that would explain it! I have an early 02... still has the CAD...which explains why mine does not come out till you let up on the right foot!

And on my truck...it's "push it out of 4x4"... not pull it out

RJ

 

I have heard that a few times! I do it all without ever looking down so no problem!

It's the Commercial Pilot in me.... got to have a check list.

RJ

 

Some of us are just turning a ****. If you turn that **** above 50mph - either direction - it does nothing. Our "smart" trucks will not engage or disengage the transfer case above that speed. My 1500 had the shifter, but I never tried it above 50mph. Are you saying that it will shift in and out above 50? Even if it does - THAT'S BAD

 

Very good info! I leave my OD on any one else not use OD?

 

shambo:

You bring up a good point about that OD switch too!

On my trucks, especially my 96' 12 valve I have tried it numerous times on both settings. I am faster if I leave it in the OFF position and just let the transmission shift by itself all the way up. Also, on my trucks, I have the ATS Transmission Controllers (Commander) which control the speed at where the TC will lock-up. I set mine down low so mine is "locked" up and that has helped me too. You would have the same thing with a manual lock-up switch.

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John_P

 

I have tried shifting to see what the outcome was.. When I shift at wide open throttle, nothing happens.. No sounds, or feelings of any type.. My MPH aslo stays identical..

 

You guys got me thinking about this, because my locking out OD came from 2 years and 250 hp ago. Just never changed how I do it.
Experimented yesterday and with present set up, at WOT... letting tranny shift into OD on it's own, it shifted out of 3rd at 3100 rpm and settled into OD at 2200 rpm. This is just what I was shooting for manually....so guess I'll change my ways!

RJ

 

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RJ:

Glad I could be of some help to you!

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John_P

 

With the hp you are at now, you would probably pickup up a little more E.T., if you installed a 4th gear switch, and force it to shift to OD sooner. The VP trucks have a tendency to "sit against the governor" for a variable amount of time (based on temp), before going into OD. Installing a OD switch and forcing it into OD at about 2800 rpm, will usually pickup a couple of tenths, as well as making it more consistent with temp changes.

Paul

 

hmmm, I've already got the 4th gear switch. I'll have to try that this year.

 

Switch sounds good... but I hate going into OD under 2000 rpm, because of my 35" tires.

I have felt/heard something that sounds like what you are describing... kind of a reluctance to shift into OD? Will have to try it.

RJ

 

I hit the lock up switch as soon as I hit 3rd. I've been trying to talk myself into hitting it 2nd.

 

I lock mine tc up as soon as it hits 2nd but he is talking about locking it into overdrive early. I have a switch for that also. It was installed mainly for dynoing but I will be giving it a shot at the track.

 

Can you explain how it differs?