my serria has a 4 wheel auto option along with the reg 4hi and 4low. i was wondering if its okay to launch at the drag strip 4wd and if so which one should i do it in?. also how much power can the stock transfer case handle? i know parish runs his truck in 4wd but he also has the transfer case out of an hd if i remember correctly. thanks in advance.

 

Use 4wd, not Auto. I have heard that you get some strange vibrations launching in auto. What I usually do is launch in 4hi, then as soon as I'm off I hit the 2hi button. It takes a few seconds for 4hi to disengage.

I believe Parish ran his stock transfer case well into the 600-700rwhp range. Someone posted specs awhile back from NVG's website and the t-case was rated at something ridiculous like 5500 lb-ft torque. I can't find the link unfortunately.

 

Here it is...

http://www.newventuregear.com/tcases.html

I lied, it's 2281 ft-lbs (mine is the NV 246).

 

so you can stay in 4wd right to the end of the 1/4? i know a lot of older trucks you couldn't run it in 4wd past a certain mph.

 

do all 1500's come with the same t-case or are there different ones?

 

Like I said, I usually shift back to 2hi as soon as I leave the line. It takes a few seconds, but by the time I'm at half track it's usually back in 2wd (at least that's what the light tells me). There have been some people that have said under WOT that the transfer case will not shift out of 4wd even though the light says it does, but I don't think it stays in 4wd.

 

Not sure about that one.

 

I think the push button auto 4wd trucks use the NV 246, the non push buttons (like mine) use the 241 I think. For most transfer cases, as long as power is being applied it will not shift into or out of 4wd. (actually it will shift into 4wd, but it doesnt sound too good) Mine will go back into 2wd, but the front driveshaft is still turning until you take the bind off of it (ie coming to a stop, or coasting)

 

2,281 Ft-Lbs may sound like a lot, but it really isn't. A stock 6.0 liter makes 380 Ft-Lbs at the crank. In first gear (3.06 ratio), the input to the transfer case can see 1,163 Ft-Lbs of torque. Drop it into low range, and the output shaft can see 2,326 Ft-Lbs of torque (so can your rear differential).

Does anyone know which case is being used in the VMAX trucks?

How about in the SS trucks?

Mike

 

With the Autotrac xfer case the front shaft always turns, so it's hard to say whether or not 4wd is engaged. I don't think it is - I stop feeling torque steer about the time the pushbutton says it's back into 2hi. I guess I could be wrong though.

Good point about low range 1st gear 83 Chevy, I forgot about low range.