what tranny do I have? Is the rear a limited slip or locker?

trx680 · 09-23-2009, 05:49 PM

I just bought a used 2001 2500hd 2wd ext cab. It has the 6.0. How do I tell which automatic tranny is has? I don't see any Allison emblems on the door, so I'm ruling that one out...I guess.

Would the rear end be a locking rear or a limited slip?

Is there a website where I can run the serial number and find out more about whats in this truck?

THANKS !!

leolkfrm · 09-23-2009, 05:58 PM

ask the dealer to run it for you and check for recalls and updates, it should help

gmctrucks · 09-24-2009, 02:15 AM

On the rearend take off from a dead stop in water or dry pavement if your GM truck goes sideways it's a posi.

1993-1997 GM 4L60E &
1997-2005 GM 4L60E C5 CorvetteHP242700 2
HP242800 2,8

HP243107 2,18
HP242962 3,9 HP243105 2
HP243106 2 ,15
HP242963 3,9
1998-up GM 4L60E F-bodyLS1/LS2 applications; 1999-up GM 4L60E/4L65E trucks w/ 4.8, 5.3, 6.0 enginesHP242935 11 ,17

HP242938 11
HP242931 10,11
1991-99 GM 4L80E

ChevyMan65 · 09-24-2009, 07:11 PM

You should be able to get the RPO , Regular Production Codes, from the glove box lid, unless they are in a different place on your yr truck, then you can decode them on GMs GMC website. Hope this helps.CM65

hotrodpc · 09-24-2009, 08:10 PM

Trans is likely to be a 4L80-E. The Allison was in the Duramax and 8.1 big block only. The RPO code may still be G80 for that year. If it is, likley to be the Eaton Gov Lock. Its Ok for pulling a boat up a wet ramp but its not a wonderful unit if that is what it has. If its not, and you have an open diff, you can put a Richmond Lock Right in it yourself without have to reset up the gears. That would be my preferance anyway.

BernieB · 09-24-2009, 09:57 PM

Quote:

Originally Posted by ChevyMan65

You should be able to get the RPO , Regular Production Codes, from the glove box lid, unless they are in a different place on your yr truck, then you can decode them on GMs GMC website. Hope this helps.CM65

I have the complete GM RPO code master list here, in PDF format, if anyone wants it.

Hmmm... maybe it's small enough to attach? Nope... it's about a meg and a half (188 pages) and the system only allows me 150kb

Okay, I stuck it on my own server. You can get it at this link: http://spwaw.com/bwb/GM-RPO-Master-List.pdf

crabtruck · 09-24-2009, 10:02 PM

So I wonder if you know someone who will let you post it on their site and link to it.

BernieB · 09-24-2009, 10:07 PM

Quote:

Originally Posted by crabtruck

So I wonder if you know someone who will let you post it on their site and link to it.

Look above your post...

crabtruck · 09-24-2009, 10:25 PM

How did you slide that past me ? I usually read all the words, even the big ones.

BernieB · 09-24-2009, 10:37 PM

Quote:

Originally Posted by crabtruck

How did you slide that past me ? I usually read all the words, even the big ones.

I am a forum ninja... You only see me when I want you to see me.

09-23-2009, 05:49 PM	#1
trx680 Full Member Join Date: Sep 2009 Posts: 13	what tranny do I have? Is the rear a limited slip or locker? I just bought a used 2001 2500hd 2wd ext cab. It has the 6.0. How do I tell which automatic tranny is has? I don't see any Allison emblems on the door, so I'm ruling that one out...I guess. Would the rear end be a locking rear or a limited slip? Is there a website where I can run the serial number and find out more about whats in this truck? THANKS !!

09-23-2009, 05:58 PM	#2
leolkfrm Senior Member Join Date: Mar 2008 Location: N.Y. Posts: 4,300	ask the dealer to run it for you and check for recalls and updates, it should help __________________ 4 wheels move the body 2 wheels move the soul B.W.A.I

09-24-2009, 08:10 PM	#5
hotrodpc Senior Member Join Date: Jul 2008 Location: OKC, OK Posts: 3,164	Trans is likely to be a 4L80-E. The Allison was in the Duramax and 8.1 big block only. The RPO code may still be G80 for that year. If it is, likley to be the Eaton Gov Lock. Its Ok for pulling a boat up a wet ramp but its not a wonderful unit if that is what it has. If its not, and you have an open diff, you can put a Richmond Lock Right in it yourself without have to reset up the gears. That would be my preferance anyway. __________________ *Winners NEVER Quit , Quitters NEVER Win !!!*

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Limited Slip Questions	blackhawk17	GMC Truck Forum	5	07-26-2008 01:00 PM
Limited Slip or Posi?	WisconsinHick	Chevy Truck Forum	18	04-03-2008 05:35 PM
Limited Slip Diff.	ct. cowboy	Chevy Truck Forum	4	03-31-2008 06:10 PM
Limited slip rear axle problem.......	truckman	Chevy Truck Forum	7	03-24-2008 10:54 AM
10 bolt rear diff with 3:73 limited slip carrier	chevyguy	Truck Classifieds	13	06-16-2006 10:21 PM

09-24-2009, 02:15 AM	#3
gmctrucks Senior Member Join Date: Nov 2006 Location: Houston,Texas Posts: 4,035	On the rearend take off from a dead stop in water or dry pavement if your GM truck goes sideways it's a posi. 1993-1997 GM 4L60E & 1997-2005 GM 4L60E C5 CorvetteHP242700 2 HP242800 2,8 HP243107 2,18 HP242962 3,9 HP243105 2 HP243106 2 ,15 HP242963 3,9 1998-up GM 4L60E F-bodyLS1/LS2 applications; 1999-up GM 4L60E/4L65E trucks w/ 4.8, 5.3, 6.0 enginesHP242935 11 ,17 HP242938 11 HP242931 10,11 1991-99 GM 4L80E

09-24-2009, 07:11 PM	#4
ChevyMan65 Senior Member Join Date: Aug 2009 Location: Northern California Posts: 64	You should be able to get the RPO , Regular Production Codes, from the glove box lid, unless they are in a different place on your yr truck, then you can decode them on GMs GMC website. Hope this helps.CM65

09-24-2009, 10:02 PM	#7
crabtruck Senior Member Join Date: Jul 2007 Location: on your 9 Posts: 3,366	So I wonder if you know someone who will let you post it on their site and link to it.

09-24-2009, 10:25 PM	#9
crabtruck Senior Member Join Date: Jul 2007 Location: on your 9 Posts: 3,366	How did you slide that past me ? I usually read all the words, even the big ones.