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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: mmusmanno on January 11, 2008, 05:05:19 pm

Title: shift on the fly transfer case
Post by: mmusmanno on January 11, 2008, 05:05:19 pm
hey guys, can anyone tell me if there is a transfer case, and if so, how to set it up, that will allow me to shift into 4wd on the fly?  my friend has a '93 1500 and he can be driving under 30mph's and shift into 4wd, and out of 4wd when he's under 30mph's as well.  with mine, like most I guess, I need to be in neutral and shift, then back into neutral to shift out and then i'm suppose to reverse for twenty feet or so to make sure its out of gear.  I have the auto locking hubs already, is there a swap to a newer or different t-case and any mods needed?  or, is it simply not easily possible?  I have an '83 k10 with the 700r4 and a 350.  thanks.  mike
Title: Re: shift on the fly transfer case
Post by: xtremjeepn on January 11, 2008, 05:24:05 pm
You should be able to shift on the fly with a 208 or 241 which were both offered on these trucks and should both dit on your 700 with the tight input shaft. (1 tons had 32 spline and your 700 is a 27 spline).  Of course this only works if you leave the front hubs locked in.
Title: Re: shift on the fly transfer case
Post by: mmusmanno on January 11, 2008, 05:28:08 pm
so, do you know what's in my truck now, or can you tell me how I determine which one?  also, it's a half ton (silverado).  the hubs are always locked, are they called auto hubs or something?  I don't have a choice to unlock them, thats why I was hoping a different t-case would be an easy solution.  which do you recommend, the 208 or 241 and what is the difference?  and, so, are you saying I need a 27 spline t-case based on having a 700r4?  this is very helpful, thanks.
Title: Re: shift on the fly transfer case
Post by: Captkaos on January 11, 2008, 05:34:28 pm
If yours is a 83 with auto hubs you are already able to shift into 4x4 at any speed below 25mph...
Title: Re: shift on the fly transfer case
Post by: Captkaos on January 11, 2008, 05:36:25 pm
An 83 pickup will only have a NP208 transfer case.
Title: Re: shift on the fly transfer case
Post by: mmusmanno on January 11, 2008, 05:47:39 pm
hmmmmm.  thats great news, except i've tried to shift on the fly and it didn't work, it's possible I didn't try hard enough, but, I don't think so.  do you know what could cause it to not let me shift on the fly?  it works from neutral no problem. 
Title: Re: shift on the fly transfer case
Post by: Fordeatinz71 on January 11, 2008, 10:13:29 pm
i'd check your fluid level.  you can only go into 4Hi, not 4Lo.  i can go out to my '83 GMC and shift into 4Hi easily at heck, even 40-45 or lower...and then back again.  mine is all still factory down to the auto locking hubs. 

it doesn't take much effort.  the linkage isn't THAT strong, so you don't wanna "haus" it too much...