w41quad4

So I know alot of guys are doing 4hi launches at the track, well with just screwing around with my 5.3 ECSB Z-71 I dont see much of a difference seat-of-the-pants launching in 4hi vs. 2hi, probably because i'm getting decent traction in 2hi. So here's the thing, I know running above 45mph in 4lo is a no-no, but the way this bitch launches in 4lo is rediculous, it just jumps, while i haven't taken it above 45 when screwing around. I'm really contemplating trying it at the track. I just wonder who has done this already and how many times till i blow it up, i could always bring a spare with just in case. What is the major concern about the transfer case when running over 45mph? is it in the case itself? the differentials? I know if really makes the gearing high, im just wondering what will break first.

-J

KySilverado

iTrader: (7)

Don't think you will be able to switch from 4WL to 4WH while moving. Damage would be to the engine I suspect above 45 mph... turning 7000 rpm.

1slow01Z71

iTrader: (36)

I have been playing around with mine too in 4lo on the concrete with my stall and nitrous trying to do a 4wheel burnout and now its starting to make a whining noise so I wouldnt recommend it.

Zick

iTrader: (18)

No the transfer case will not switch out of 4Low at any speed over 5mph. If it does it will probably destroy something.

w41quad4

I know for a fact that it wont switch out of 4lo doing anything over 5mph. I was just wondering how everything else was effected during hi-speed use. I wonder what kind of RPM i'd be turning running close to 100mph haha.

1slow01Z71

iTrader: (36)

rpm

Seriously you cant run 100 in 4lo I think the max you could run is probably around 55-65. I would be turning 6000 at 30mph in 2nd so I doubt you could get to 100 since 2-3 and 3-4 are spaced closer together than 1-2. Dont do it and hp to get you there. People launch in 4hi to get better traction once you get alot more hp where it is hard to get traction in 2wd.

OBXMarine

iTrader: (2)

I have to place the tranny in neutral before the transfer case will switch in/out of 4LO.

1slow01Z71

iTrader: (36)

Me too but I think what he is wondering is if he can run the 1/4 in 4lo which there is no way in hell. Maybe in the 1/8 mile but I still doubt it though.

white1

iTrader: (5)

I bet he'd have some killer 60' times though

marcus769

I really dont know alot about the workings of transfers, and 4-wheel drive equipment, but what i do know, i learned first hand. My buddy scored a 1996 GMC Jimmy and thought 4 wheel drive was just ******* cool. He as always testing how far he could go before he got stuck, and just how cool the Torque felt in 4lo. well after showing us all how ridiculously fast it could take off, a month later, a HUGE *** piece of his axle shaft or some type of shaft just completely broke. Looked to be a pinion gear shaft of some sort.?. It was not very long. I am guessing it was 2" diam. and just broke from all the torque. The damn truck only had the 4.3, and your trucks are putting down at least 100 more HP to the wheels. I am guessing That may be a piece that will fail in your trucks!? What he ended up paying from ******* around like that was not worth it. If i were you, i would not play around with 4lo unless absolutely needed. Sorry i could not get into specifics, but i am lacking the knowlege of this area. For all thats worth, I hope it helps.? Keep truckin' guys.