New transmission for upgraded 5.3L engine?

[Mudsport96]

Why would a reflash of the pcm be needed if beefing up internally a 4l60e to a 4l65e? Would that be if only going to a 5 planetary from the stock 4 planetary? I'm confused on this.

You dont. Programming doesn't care.

But the 65e also has a different design converter and input shaft that doesn't play nice with older style blocks. Thats why if you use an older 4l60e/700r4/th350/th400/200-4r behind a gen3 engine ( that isnt one of the oddball early "long crank" engines) you have to use the spacer and offset flexplate to support the converter. Or buy a specialty converter.
But that is a moot point because basically all 5.3s use the 300mm style transmission. Early 4.8 MANUAL equipped engines and the early (99-00) 6.0s had the odd cranks so just avoid 99-01 transmissions to be safe.

 

[Tonyrodz]

You dont. Programming doesn't care.

But the 65e also has a different design converter and input shaft that doesn't play nice with older style blocks. Thats why if you use an older 4l60e/700r4/th350/th400/200-4r behind a gen3 engine ( that isnt one of the oddball early "long crank" engines) you have to use the spacer and offset flexplate to support the converter. Or buy a specialty converter.
But that is a moot point because basically all 5.3s use the 300mm style transmission. Early 4.8 MANUAL equipped engines and the early (99-00) 6.0s had the odd cranks so just avoid 99-01 transmissions to be safe.

This is why I sold an iron headed 6.0 I had bought. I didn't want to mess with flex plate or crank spacers to use in my 03.

 

[S33k3r]

Not sure what you are talking about ????

It was supposed to be a joke about collecting insurance money after the Tahoe blew up...

 

[Bill Barnes]

The key differences between a 4L60E and 4L65E are: (1) Hardened 300mm input shaft (2) 5 pinion Planetary (3)Hardened sunshell
Its not very common to have problems with the input shaft but the 4 pinion planetary and non hardened sunshell of the 4L60E create very common problems of failure behind a modified engine and even stock engines.
The 4L60E has a 298mm input shaft and torque converter specific to that. The 4L65E has a 300mm input shaft and torque converter specific to that input shaft. The torque converters are NOT interchangeable without a input shaft swap. You can stick a 5 pinion planetary (4L65E) directly into a 4L60E tranny during rebuild. No mods at all necessary for that swap. Simple drop in. The 5 pinion spreads the load out across 5 pinions instead of 4. The beast sunshell or equivalent is a direct swap in no mods required and is a hardened part. The oem sunshell is prone to its splines stripping out or breaks at the welded area.
If a 4L65E tranny is installed into a 4L60E application then a PCM reprogram will be needed.
The 4L60E and 4L65E are the same external dimensions because the 4L65E is just a beefed up 4L60E from the GM engineers. Same gear ratios.
RPO code for 4L60E is M30 and the 4L65E is M32. GM started internal changes/upgrades to the 4L60E in 2001.
To make matters even more confusing it is possible to have a factory "M32 badged" 4L60E that is factory upgraded but has a M30 RPO code but it is not a true 4L65E but instead is a in between.
"If you are looking at the transmission itself, the M32 number should be listed on the transmission itself. M32 is also a high performance version of the 4L60E, depending on the year. It’s really confusing."

4L65E Transmission | Drivetrain Resource

4L65E Identification, RPO Codes, Specs, and differences between it and the 4L60E can be found on this page.

www.700r4transmissionhq.com

I just checked my RPOs, and I do have the M30 (4L60E). I will look for a performance Trans shop locally. I really appreciate all of the info you all have provided.

 

[rockola1971]

Why would a reflash of the pcm be needed if beefing up internally a 4l60e to a 4l65e? Would that be if only going to a 5 planetary from the stock 4 planetary? I'm confused on this.

Thats not what was said. "If a 4L65E tranny is installed into a 4L60E application then a PCM reprogram will be needed.".
If someone took a 4L65E tranny, a true M32 and stuck it in an originally equipped 4L60E(M30) equipped vehicle a reflash would need to be performed. The reason is because the pinout is different at the tranny so the outputs of the PCM have to be reprogrammed. Dont want 1st gear commanded by the PCM and it ends up going to 4th gear solenoid at the tranny.
If a 4L60E is upgraded to 4L65E specs for the hard parts then nothing else needs to be done except put fluid in it and try to burn it up.

 

[Mudsport96]

Thats not what was said. "If a 4L65E tranny is installed into a 4L60E application then a PCM reprogram will be needed.".
If someone took a 4L65E tranny, a true M32 and stuck it in an originally equipped 4L60E(M30) equipped vehicle a reflash would need to be performed. The reason is because the pinout is different at the tranny so the outputs of the PCM have to be reprogrammed. Dont want 1st gear commanded by the PCM and it ends up going to 4th gear solenoid at the tranny.
If a 4L60E is upgraded to 4L65E specs for the hard parts then nothing else needs to be done except put fluid in it and try to burn it up.

From what i can find the pinouts only show the input speed sensor wiring to be the only difference in the plug. So a 65e should not require a reflash.

Now a 60e into a 65e application can not be used as there is no iss for the ecm to read

 

[Smutty j]

The key differences between a 4L60E and 4L65E are: (1) Hardened 300mm input shaft (2) 5 pinion Planetary (3)Hardened sunshell
Its not very common to have problems with the input shaft but the 4 pinion planetary and non hardened sunshell of the 4L60E create very common problems of failure behind a modified engine and even stock engines.
The 4L60E has a 298mm input shaft and torque converter specific to that. The 4L65E has a 300mm input shaft and torque converter specific to that input shaft. The torque converters are NOT interchangeable without a input shaft swap. You can stick a 5 pinion planetary (4L65E) directly into a 4L60E tranny during rebuild. No mods at all necessary for that swap. Simple drop in. The 5 pinion spreads the load out across 5 pinions instead of 4. The beast sunshell or equivalent is a direct swap in no mods required and is a hardened part. The oem sunshell is prone to its splines stripping out or breaks at the welded area.
If a 4L65E tranny is installed into a 4L60E application then a PCM reprogram will be needed.
The 4L60E and 4L65E are the same external dimensions because the 4L65E is just a beefed up 4L60E from the GM engineers. Same gear ratios.
RPO code for 4L60E is M30 and the 4L65E is M32. GM started internal changes/upgrades to the 4L60E in 2001.
To make matters even more confusing it is possible to have a factory "M32 badged" 4L60E that is factory upgraded but has a M30 RPO code but it is not a true 4L65E but instead is a in between.
"If you are looking at the transmission itself, the M32 number should be listed on the transmission itself. M32 is also a high performance version of the 4L60E, depending on the year. It’s really confusing."

4L65E Transmission | Drivetrain Resource

4L65E Identification, RPO Codes, Specs, and differences between it and the 4L60E can be found on this page.

www.700r4transmissionhq.com

Good info. Really appreciate it. Thanks!

 

[2006Tahoe2WD]

I feel that I want my transmission rebuilt or swapped out with a rebuilt unit. I assume I have a 4L60. The vehicle is a 2006 5.3 Tahoe. What companies are recommended if I don't trust a local tans. shop? Monster? I guess I would order the transmission and send back my core after the swap. What's wrong with this plan?