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Discussion Starter · #1 · (Edited)
How do I identify both my differentials, transfer case and transmission?

I am looking for transmission model number (4L60-e? 4L65-e? pan doesn't say like I'm used to)

Looking for rear gear size (in inches). I know I have a G80, 3.73 ratio, but thats all I know.

Mostly curious for fluid fill specs... front shouldn't be a big deal...but for the rear, it can vary quite a bit it seems.

I will get under there and look for any tags I can find in addition.

Automatic Transmission, 4L60E -65E Initial Fill..........5.0 quarts[1]
Automatic Transmission, Total Fill
4 speed 4L60E..........11.0 quarts
4 speed 4L80E..........14.0 quarts
Differential, with 8.25 ring gear Front..........3.0 pints
Differential, with 9.25 ring gear Front..........3.2 pints
Differential, with 8.6 ring gear Rear..........4.2 pints
Differential, with 9.5 ring gear Rear..........5.5 pints
Differential, with 10.5 ring gear Rear..........5.5 pints
Differential, with 11.5 ring gear Rear..........7.6 pints
Transfer Case,NP8..........4.0 pints
Transfer Case,NR3..........3.0 pints
Transfer Case,NVG 263-NP1..........4.0 pints
Transfer Case,NVG 261-NP2..........4.0 pints
Transfer Case,NVG 246-NP8..........4.0 pints


Thanks!:money:
 

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We have an RPO master list. Or at least someone downloaded it for us.

It is quite long, 188 pages in adobe.

If you like I will try and e-mail you a copy, but to put the entire list on here would take up way to much bandwidth, I think.
If you look in the glove box there is a label with all of the things installed in your truck. That is your RPO list.

There is an online decoder available from our friends who have corvettes, but I have found some of the codes are missing.

http://s-series.org/rpo/
 

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As for identifying parts on the truck, that shouldn't be TOO hard. First of all, what is it, 1500, 2500, 3500, etc? The 1500s for the most part come with 4L60-Es for transmissions (if it's 92-current, 91 and earlier has a TH700R4 or other TH transmission.). To idnetify your rear-end, the easiest thing is to count the bolts. I'm fairly sure most 1500s have a semi-floating 10-bolt 8.5" rearend. To find out, count the bolts holding the drain pan on the back of the diff. You have 10-bolt, 12-bolt, and 14-bolt GM diffenetials, and you could possibly have a Dana rearend, which I'm not 100% sure on how to identify. For the front diff, it should be the same process. I am pretty sure they just use modified rear diffs for the front, so the center chunks are still the same, 10, 12, 14 bolt or a Dana axle. Hope this helps.

EDIT: This Page http://www.lmctruck.com/icatalog/csb/full.asp?page=12 should help idnetify your tranny and diffs. If you don't have a suburban, don't worry, the trannies and diffs used are the same across all GM trucks...
Try looking on www.gmpartsclub.com
Chevy Engine
 

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Discussion Starter · #4 ·
Alright, well its the truck in my sig.

04 Avalanche 1500, GMT-800 Suburban platform.

Alright, well before coming back and reading this I looked it up somewhere else, (can't remember where) for replacement parts...and by doing that, identified it. I should have a 8.5" semi float G80 locking diff in the rear and 8.25" in the front, that helps alot.

It also has the 4L60E, so that helps alot.

Pretty much good! thanks very much for the info, that was easier than I thought it would be.

Still having an issue identifying the transfer case though.

I know quite a bit about RPO codes, I've already done a whole list of them, but it didn't tell me everything....had a bit of trouble finding SOME of the codes, those are probably the drivetrain ones.

http://www.bonnevilleclub.com/forum/viewtopic.php?p=1011751
 

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We have or at least I have the entire GM RPO codes list in my computer in a PDF file, as I said it is quite long. If you know the codes that you have not been able to find elsewhere post them and I can look them up on my list for you.
 
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