GM 4L60E Transmission Teardown pt. 1

i am going to begin disassembly of my 4L60E.  many of the same internal parts of this line of transmission apply to the 700R4 with the exception of the valve body components. so i am going to deal with the removal and inspection of these separate. first off the biggest difference is that we have an aluminum valve body instead of cast iron like the older trannys. so use caution when handling it as the edges are like a knife if you get careless!

 

S3700015So the ATSG book said to start with the 2-4 servo cover here-the book i got from summit racing said to start with the tail housing. personally to save you a headache start with the valve body. after busting some components trying to follow the atsg manual, i would say start by removing the oil pan, filter, and wiring harness.i didn’t get a picture of it complete with the wiring harness but here it is after the harness is removed to give you an idea.

 

 

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when removing the wiring harness, the solenoid right above the torque converter clutch solenoid must be removed. i believe this is the 3-2 solenoid to the front of the valve body. it is simply held in by a spring  clip just above the solenoid….and will fly off across the shop. these solenoids were pulse motors early on and later were a more simple on/off style solenoid.

 

 

 hereS3700006 we have removed the torque converter clutch solenoid, or rather TCC. this MUST be removed prior to pulling the pump out otherwise you will break the damn thing off. as you can see that’s what i did cause i was following the wrong manual. it is wired in one piece to the harness and comes off with it rather than just a connector like everything else. these are prone to cracking causing converter failure. you can check these with air pressure if you are careful, but if you have an older one and are unsure- spend some money.

 

hereS3700009 i have removed the pulse width modulator (PWM)solenoid so you can get a good viel of the connector going through the case. there is a special tool to remove the connector via pressing the fingers on the top of the case and pushing it through the bottom. you can also use a buddy with small screwdrivers while wiggling it- or a large socket. the prongs will break if you just yank it out. you can leave the pwm in and remove the valve body first to remove this connector a lot easier.

 

NowS3700045 at this point you can turn either turn you attention to everything else and remove the valve body last, or remove the valve body and stuff now and set it aside for later service and inspection. i am going to go the route of getting the valve body the rest of the way off. next out after the harness remove the pressure switch manifold and set it aside. you can also see it’s location in the first picture above. i would also remove the selector tension spring at this point as well just to make life easier later on.

 

nextS3700073 remove you valve body bolts and your valve body assembly. there are check balls located on both sides of the transmission  separator plate and can vary with the years, so have the tranny inverted and pull the valve body straight off. usually the check balls will remain in place…if not be stuck in the mid plate.  remove your check balls. the 1-2 accumulator is in the upper left hand corner holding everything in still as well as the plate to the rear.

 

 

hereS3700071 is when you can take note of your valve body gaskets and what mid plate you have. the mid plate is stamped with a letter designation and the orientation of the gaskets is also marked. if you are investigating a failure this is a place to stop and take notes to see if someone else didn’t screw it up at some point during a prior build….or you need a different mid plate. my fingers are pointed to a “V” and a “C” as the gaskets are marked.

 

 

 you can then removeS3700049 the 1-2 accumulator, rear coverS3700052 plate, and mid plate/gaskets. the bottom half of the 1-2 accumulator is below the mid plate and can also be removed. the pin  at the center of the piston pulls from the case. these accumulator pistons can be a high wear item so inspect them closely before re-installation. note the locations of the rest of your check balls at this time as well. here i am pointing to an encapsulated check ball to the rear of the case. this is suppose to stay in place but can fall out due to wear. this needs to also be checked out before re-assembly. also note the check ball near my thumb in the case that is loose. this one is easy to overlook during re-assembly so take note not to forget.

 

last thing inS3700051 this part of the tranny is the 2-4 band anchor pin. now depending on where you started this may just fall out of it may have to be pushed out after you remove the front pump and/or the 2-4 servo.  at this point you can also remove your selector shaft and parking lever engagements. you can now turn your attention to the rest of the tranny for disassembly.                                                             

 

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