4L60E Teardown and Inspection (Full Length Version)

I tear down and inspect a late 2000 model year 4L60E that went behind a 6.0L Gen III small block (LQ4 probably) and provide a high level overview and history of these transmissions, cover points of inspection as well as discuss drivability symptoms and causes. I also touch on considerations for rebuild, including stock vs high performance along with parts selection. Lastly, I briefly show the tools needed to disassemble the transmission.

It typically takes me about 35-40 minutes to completely tear down a 4L60E, including all subassemblies then another 20-30 min to fully examine each part however this video is lengthy and contains no "fast forward" sections as I wanted to capture as much pertinent information as possible so it ran very long. Feel free to skip around based on the TOC below.

Table of Contents:
0:00 - 4:40 - Intro, Overview and Tools
4:41 - 13:33 - Bell Housing Removal with a Torch
13:14 - 33:48 - External Case (lots of discussion in addition to disassembly)
33:49 - 56:26 - Pan through Case Belly
56:27 - 1:12:00 - Pump examination
1:13:00 - 1:21:00 - Reverse Input Drum examination
1:22:00 - 1:47:00 - Forward Drum examination
1:48:00 - 2:21:00 - Remaining Internal Case examination
2:22:00 - 2:27:00 - Bonus Footage: Valve Body Testing using Sonnax Vacuum Tester

Bonus Footage Note: I neglected to reset the low range calibration of the Sonnax tester so all my readings are 5 Hg high. For the valve body under test, those are still acceptable figures for a stock or mild performance application. I will film a separate, more in-depth video using the tester on a valve bodies and pumps as well as the valve body bore ream/repair process in the next few weeks.

Content Note: I'm sure I missed a few things so if you would like me to delve into anything specific that I either failed to cover or only superficially touched upon, let me know in the comments and I'll make a separate video on it.

Addl Pump Info: Check the stator journal for wear/heat damage. Replace the filter pickup seal in the pump on overhaul. "PWM", as cast into the pump body, stands for Pulse Width Modulation and refers to the torque converter clutch apply strategy that GM introduced in the 4L60Es starting in 1995.

Addl Forward Drum Info: Make sure the existing sealing rings move freely in their respective grooves. Worn lip seals can also cause slippage and/or clutch burn up.