Jump to content

Transfer case info

Doonatic
 Share

Recommended Posts

Doonatic Enthusiast

Doonatic

Posted
Posted

Hey yall, got a question for you. For the 2003 2500hd’s, Chevy offered 3 different types of transfer cases. Does anyone know how to identify which transfer case is installed in the vehicle one may have.

 

I am moving into my 3RD transfer case (factory installed chain ground a hole through the case years ago, dealer installed a “new” used one, and now this one will not engage reverse). I am vigorously searching for a new case NOW, because I am afraid my vehicle will leave me stranded very soon. (Side note: I get a grinding noise-like the chain is rubbing ONLY during coasting.)

 

So if anyone can help me find the part numbers or the direction to locate said replacement parts, that would be amazing.

OldGuy96 Enthusiast

OldGuy96

Posted
Posted

Are you sure it's the transfer case? If it will engage 4WD Hi and Lo, then the transfer case isn't your problem. If the truck won't go into reverse, you probably have a transmission problem.

PTXer Enthusiast

PTXer

Posted
Posted

What is your RPO code?  That should narrow it down.  It might be stamped/labeled on the case as well.

Doonatic Enthusiast

Doonatic

Posted
  • Author
Posted
21 hours ago, OldGuy96 said:

Are you sure it's the transfer case? If it will engage 4WD Hi and Lo, then the transfer case isn't your problem. If the truck won't go into reverse, you probably have a transmission problem.

Old guy, i thought that as well, however when it is in reverse the noise that is emmitting from underneath is coming from the transfer case, not the transmission. Its as if it is a solenoid motor that is not engaging.

Doonatic Enthusiast

Doonatic

Posted
  • Author
Posted
8 hours ago, PTXer said:

What is your RPO code?  That should narrow it down.  It might be stamped/labeled on the case as well.

RPO code?

newdude Senior Enthusiast

newdude

Posted
Posted (edited)

GM used two transfer cases in 2500HD trucks (2001-2007 classic), the NVG 261 and NVG 263 transfer case.  The 261 is the manual shift 2 speed case (floor shift), RPO code on the build label is NP2.  The 263 case is the electronic shift 2 speed case, RPO code on the build label NP1. 

 

There is some internal differences in the cases between the gas mated to 4L80, and gas/diesel mated to Allison cases in terms of gears, chains, input shafts, etc.   

 

I believe ones bolted to the Allison had "HD" or "XHD" tagged at the end of the case number on the NVG stamp on the rear.  NVG261/3 XHD/NVG261/3 HD. 

Edited by newdude
carkhz316 Enthusiast

carkhz316

Posted
Posted
3 hours ago, newdude said:

GM used two transfer cases in 2500HD trucks (2001-2007 classic), the NVG 261 and NVG 263 transfer case.  The 261 is the manual shift 2 speed case (floor shift), RPO code on the build label is NP2.  The 263 case is the electronic shift 2 speed case, RPO code on the build label NP1. 

 

There is some internal differences in the cases between the gas mated to 4L80, and gas/diesel mated to Allison cases in terms of gears, chains, input shafts, etc.   

 

I believe ones bolted to the Allison had "HD" or "XHD" tagged at the end of the case number on the NVG stamp on the rear.  NVG261/3 XHD/NVG261/3 HD. 

Just tagging on to this to confirm what you mentioned about the Allison-equipped trucks (8.1/ Duramax). They are 261/3 XHD as you stated. Only real differences with the XHD variants are the larger output shafts, and different oil pumps. Otherwise, most of the guts are the same.

  • Like 1
newdude Senior Enthusiast

newdude

Posted
Posted
10 hours ago, carkhz316 said:

Just tagging on to this to confirm what you mentioned about the Allison-equipped trucks (8.1/ Duramax). They are 261/3 XHD as you stated. Only real differences with the XHD variants are the larger output shafts, and different oil pumps. Otherwise, most of the guts are the same.

 

Thanks for the clarification.  :thumbs:

  • Like 1
  • 3 years later...
swathdiver Senior Enthusiast

swathdiver

Posted
Posted
On 5/23/2022 at 8:32 AM, LarsonFarms said:

Will a 2005 transfer case work in a 2008 Chevy 1500?

It is not a direct bolt on, plug in and go.  I would say no, but exactly which transfer cases are in question here?  My brain thinks of the 246 and MP3023 which are electronic.

  • 2 years later...
Steven suzor New Member

Steven suzor

Posted
Posted

Mine is stuck in 4 low will not come out. Sounded like an explosion constant grinding even when truck is in park.  My truck is still in neutral and making the grinding noise. 2003 GMC Sierra 1500

davester Senior Enthusiast

davester

Posted
Posted

No, get the same TC as what's in the truck.

 

You might be able to manually shift what mode the TC is in, by removing the encoder from it, then manually rotating the post to the mode you want.  It may take some fiddling ton find which position is for 2hi

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • Grumpy Bear
      Gas Prices

      By Grumpy Bear · Posted

      Sir, economics doesn't have a moral compass. 😉 Just say'n. 
    • Grumpy Bear
      OCI, not when but why?

      By Grumpy Bear · Posted

      One would think. BUT....This is what a Google search gives for the GM OLM system:    It doesn't measure oil condition save the highly indirect water temperature. It should measure oil temperature and as we've discussed they are not as closely related as one might assume. The algorithm is based on expected conditions at the end of a certain number of miles or revolutions. And sirs, this estimated value is not tilted in the engines favor. It favors the OEM's bottom line. There are no magical number of miles nor revolutions. No magical time limit. There is only what can be measured directly and only in the broadest of terms would the values used even come close to reality.    It samples nothing. It has no idea where the oil started or where it will finish given the limited values use to create the algorithm. It is just a reminder for the brain dead to do something at some time to keep the warranty in tact. Pure fiction.    Key Factors in Oil Life Calculation The OLM calculates the remaining oil life percentage based on the following factors: Factor Description Engine Revolutions Tracks the number of engine revolutions since the last reset, decreasing oil life with use. Mileage Since Last Reset Monitors the distance driven since the last oil change, capped at 7,500 miles for most models. Time Since Reset Decreases oil life over time, dropping to 0% after one year, regardless of mileage. Engine Temperature Adjusts oil life based on coolant temperature; exceeding 260°F sets oil life to 0%.  
    • BDS my HD
      Brand new to this forum. Questions about re-gearing my 26’ HD

      By BDS my HD · Posted

      Towing power and I guess MPG matter that’s why I may end up going with a gear swap as soon as they’re available for this truck if I’m correct
    • GMTruckGuy74
      2027 Chevrolet Silverado: Official Discussion

      By GMTruckGuy74 · Posted

      If I may, I'd like to post my prediction of the trim levels for the 2027 GMC Sierra, based on what was released/introduced today about the Chevy Silverado.   Using the "Professional Grade" wording already in use by GMC, here are the eight (8) trims I believe the Sierra will offer (comparable Chevy trim in parenthesis): Sierra Pro (Work Truck/WT) Elevation (Custom) Elevation Premium -or- Ultimate (Silverado) AT4 (Custom Trail Boss) AT4 Premium -or- Ultimate (Trail Boss) AT4X (ZR2) Denali (High Country) Denali Ultimate (N/A) If GMC would rather simplify the trim levels, then I predict six (6) with package upgrades in parenthesis: Sierra Pro (with a Graphite package upgrade option) Elevation (with a Premium -or- Ultimate package upgrade) AT4 (with a Premium -or- Ultimate package upgrade) AT4X (with AEV and Ultimate packages upgrade) Denali Denali Ultimate  Let's see if I'm close.
    • revmanii
      Auto start stop disable

      By revmanii · Posted

      I have to believe there are already a bunch of threads on this, but my searches didn't turn up much. While I like the ease of a plugin solution like the Carbyte, It appears it disables the AFM or DFM too, and is not configurable to only disable the auto stop/start. So, I'm looking at the Autostop Eliminator product. I like the idea of it better, but I'm concerned about the install and having to pull so many panels to get it installed. Mines a 2026 work truck, so from what I've read it's a less involved install, but having watched a couple install vid's, I'm still a little intimidated. Might need to buy some plastic trim tools to get it done without breaking or marring stuff. Any experience intalling in a WT greatly appreciated.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...