4l70E swapped for 4l65E accidentally ?? have questions


Original poster
Mar 17, 2023
Lockport IL
I have an 07 Tahoe and the trans went out I was told I had a 4l60E transmission. when I ordered a new Trans from Monster Transmissions and provided my VIN they told me that according to my Vin I actually had the 4l65E. I had my nephew replace the trans for me and shortly after driving it for about a week I started getting codes P0717 & P0700 and didn't know why so I contacted MT about this and they said My original trans was a 4L700E and that I needed to now pay them a restocking fee plus shipping to swap the transmission almost an additional $1000. my question is what is the difference between these 2 transmissions and do I have to swap them? Aside from the codes it seems to run and drive fine ( it does shift more aggressively 1st into second and 2nd into third ) but it is a performance trans with a corvette servo.


May 23, 2021
Tempe, AZ
Welcome aboard! Looks like the main difference between the 4L65E and the 4L70E is the input speed sensor; the 4L70E has one and the 4L65E does not. That would explain the P0717 code (Input/Turbine Speed Sensor Circuit No Signal). Other than the code, and all else being equal or better, I don't see any problem keeping the 4L70E. Here is a nice summary of the 4L70E differences vs. the 4L60E & 4L65E: All About the 4L70E
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Supporting Donor
Dec 3, 2011
Brighton, CO
I think I would be telling MT that they provided you a transmission based on the VIN.. Its on them to make sure its correct because you bought what THEY told you to buy. Thats not your fault.


Lifetime VIP Donor
Supporting Donor
Oct 22, 2015
Tampa Bay Area
This might prove an unusual place to *Find a Fix* but perhaps THIS can solve this issue:



Dec 4, 2011
Ottawa, ON
First of all, confirm which tranny you're supposed to have. Check the RPO codes in the glove box. Find one of these (thanks @azswiss ):

M30: 4L60E
M32: 4L65E
M70: 4L70E

Next, it would be totally ON THEM to fix this since it was THEIR mistake.

Now if they're still being hardasses, then one option might be to tune out the P0717 although I have no idea what that sensor really does. You might also need to repin the connector as that might be why it's throwing the P0700 as there are differences in pin locations.

One caveat though if keeping it. The 4L70E was usually behind 6.0L engines (I had it in my 6.0L Avalanche) because it is beefed up to take that power. It was also behind the LS2 6.0L in the TBSS. The 4L65E might not be as beefed up as much as the 70 but maybe because it's from a rebuilder named Monster Transmission, it might have been beefed up to the same or better than the 70. And I don't know what effect the input sensor would effect the shifting or other operations. A tuner may be able to totally delete that sensor and its error codes.

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