4T65-E (and HD) ID TAG deciphering info

[Sinister Performance]

4T65-E (and HD) ID TAG deciphering info can be found here:

GM FWD Transmission ID charts

-ryan

[04GPCOMPG]

How would I know if I have the HD trans or not? I found the tag, and found the "code" but what I see does not match what's on the list. I took a crappy pic with my phone, but I don't know how to post it. All that it says is just "4CB" there is no "CAB" OR "CBB". Can anyone help?

[Sinister Performance]

How would I know if I have the HD trans or not? I found the tag, and found the "code" but what I see does not match what's on the list. I took a crappy pic with my phone, but I don't know how to post it. All that it says is just "4CB" there is no "CAB" OR "CBB". Can anyone help?

Sounds like you have a "4CBB" trans, which equates to a 2004 4T65-E NON-HD unit with 3.29:1 overall gearing.

If you don't have the supercharged engine, then you don't have an HD trans (if everything is factory under your hood and someone hasn't replaced the trans already).

[04GPCOMPG]

Sounds like you have a "4CBB" trans, which equates to a 2004 4T65-E NON-HD unit with 3.29:1 overall gearing.

If you don't have the supercharged engine, then you don't have an HD trans (if everything is factory under your hood and someone hasn't replaced the trans already).

See that's what confuses me, cuz I do have the L32 SC, and as far as I know everything is stock. I bought it used and got a print out of all service work done on the car, and didn't see anything about the trans being replaced.

[Trannyman95]

I just built one of these a month or two back and 4CB is the CompG HD trans with 3.29 gearing and tapshift option, so that is correct. It is a different code for the normal GTP as they had the 2.93 gearing and I dont believe they had the tapshift but I could be wrong on that. Ryan the ATSG book has the wrong info for that trans and I wrote it down in my book for future referrence. The correct info for the 4CB trans is Supercharged/JZFM converter/258mm/IMS= Y

[04GPCOMPG]

Well that is good to know, thanks for your help. So then what makes it different or better?

[Trannyman95]

The Comp G cars got a 3.29 overall ratio vs a 2.93 overall ratio for better performance, the valvebody, seperator plate, and channel plate are specific to the tapshift cars as they use a different shifting strategy than the normal cars. The torque converter is a slightly different stall rating to match the package. The internals are the same as all of the other 4T65Es as far as clutch packs and geartrain

[Sinister Performance]

Ryan the ATSG book has the wrong info for that trans and I wrote it down in my book for future referrence. The correct info for the 4CB trans is Supercharged/JZFM converter/258mm/IMS= Y

I will correct the info on my website. Thanks for the update!