2008 5.3 transmission question

[cru_zn_29]

I have a 2008 5.3 I have found a 4l65e trans from a 2003 all wheel drive escalade that will need to have the output shaft change and tail housing change. What else will I have problems with. Will that transmission work with the newer e38 and electrical equipment .

[clinebarger]

The short answer is yes it can work.

To give you a better answer.....
Do you have the PCM(E38) & TCM(T42) from the '08 donor vehicle?

I ask because I get about 1 vehicle a month in the shop with a mismatched PCM & TCM, Example.....You can not use a '11 Escalade E38 with a '07 Silverado T42, Also you can't reflash the later PCM's to an earlier OS (It will Brick the PCM)

'07 & '08 E38's & a matching T42 are the easiest to work with if your running a 4L60E/4L80E.

An '08 4L60E has a ISS (Input speed sensor), The '03 4L65E will not, This can be handled with tuning.
The internal trans harness is also different, If using a stock '08 harness......The trans plug will need to be repined for the '03 trans.

[cru_zn_29]

Yes I have the e38 and the TCM from the avalanche and the harness.

[clinebarger]

Originally Posted by cru_zn_29

Yes I have the e38 and the TCM from the avalanche and the harness.

I have to ask, Where is the original trans from the Avalanche?

[cru_zn_29]

I don't know I bought the motor on Craigslist in 2011 I found a 4l70e from a 2008 Silverado about a hour ago will pickup on Monday It should work out better than the 4l65e it was going to be a long road trip.

[clinebarger]

Using a '08 trans makes it easier, For it to be a 4L70E/4L65E.....It would have had to come from 6.0L 1/2 ton truck, Or a Trailblazer SS.

They are quite rare (To find a good one just laying around), I have seen many people get sold a burned-up 4L60E for Good 4L65E prices.

Unfortunately there is no way to verify it is 65E/70E without tearing the unit down.

[cru_zn_29]

Thanks for the info very helpful. I have read that if the trans still has it's Transmission Broadcast code with bar code on the top of the main case. The first number is the year then three letter codes. Example 8KZD = 2008 4l65e 4x4 13pin 8DMD 4l70e 15 pin there are a lot of different ones those were wrote down for samples. But some I have seen also had the number & letters painted black on the side of the main case and bar code and TBC on top. I Know what you are saying about sellers saying its a 4l65e and it is a 4l60e. That's why I carry my codes with me and ask a lot of questions

[cru_zn_29]

The 4l70e I went to get turned out to be a 4l60e. I have had such bad luck finding a 4l70e I am going with a 4l80e from a 2004 Silverado 2500. What problems will I have with my wire harness and TCM from the 2008 5.3.

[dayj1]

Originally Posted by cru_zn_29

The 4l70e I went to get turned out to be a 4l60e. I have had such bad luck finding a 4l70e I am going with a 4l80e from a 2004 Silverado 2500. What problems will I have with my wire harness and TCM from the 2008 5.3.

I put a 4l80 behind the 2007 5.3 (LY5) in my '57 BelAir. I documented the procedure when I did this back in 2013.

1) At the transmission connector, remove the wires at pins "K" (orange), "S" (white), "T" (tan-black), "U"(brown), and "V"(Light Blue).

2) Take the brown wire (that used to go to pin "U") and put it in the transmission connector at pin "S".

3) We won't be using the wires that used to go to "S"(white) or "T"(tan-black). Just tie them up in the harness or strip them out if you prefer.

4) Take the wire that used to go to "K" (orange) and "V"(Light Blue) and run them to the external ISS on the 4L80. Of course, you'll need a connector from an old wiring harness or grab one at the junk yard. Pretty much all the VSS sensors use this 2-pin connector. It doesn't matter which wire is which on this two wire connection as it's an AC signal.

5) At the TCM connector remove the wires at pins "14"(White) and "25"(Tan-Black). This is the other end of the extra wires from step "3". Tie them up in the harness since they're disconnected at both ends or strip them out of the harness if you prefer.

6) Remove the wire at pin "45"(light blue) of the TCM connector and put it in pin "26".

7) You'll need a TCM from a 2008-2009 Express van (2500 or 3500). The hardware number is "24240449". The service number is "242423918290" Those numbers are right on the label on the TCM. I got one off eBay for $49 shipped because I was in a hurry. If you're willing to wait they're out there for $25. I just replaced my Silverado TCM with the Express van TCM. No programming required, just plug and play.

8) Enjoy your new 4L80!

Like I said, that was from 2013. I'm sure HP Tuners has been updated since then, but, at the time, they didn't offer a transmission segment swap for Gen 4 ECMs. Hence, the need to purchase the Van TCM.

[cru_zn_29]

Thanks for info on repining the harness from 4l60e to 4l80e. I am reworking my wire harness an would like to shorten some wires. I am looking for GM part #s new ECM terminals I have gone to the Napa store the ones they had were the wrong size.