Project K1500: Transmission Overhaul Part I Overview and Detachment

Rebuilding a 4L60E Automatic Transmission

Aug. 01, 2007 By Jarred Meyer
 
About 210,000 miles later I have finally decided to direct my attention to the transmission. It is the original, stock tranny that came with the truck all of about 14 years ago and has not had any complications. Knowing that the 4L60e tranny that came with this truck has an average life-span of about 150,000 miles made me become pro-active on this project. Well, I guess I’m a little over 50,000 miles late but then this 4L60e has been great!

            To start out I will tell you that I am a complete rookie when it comes to even dropping a transmission much less rebuilding one, but with a little help from my parts supplier, Dana, from Pro-Built Automatics, and a couple of Hanes manual’s I anticipate this project will go smoothly. Once I complete the teardown I may choose to bring a local transmission shop into the rebuilding portion, but that decision will come after I get the tranny disassembled.

            The project will be divided into a few different segments as I am spreading it out over a couple of weeks. With a job like this it is better to take your time, and with a bench-top job segmentation can easily be accommodated. This first phase will involve the removal, or “detachment” of the transmission from Project K1500. Like I said before, I have not previously removed a transmission from a vehicle before and since my methods may not be accepted practice, be sure to contact a professional mechanic, or in any case a Hanes manual before beginning a project like this. Also dropping a transmission can be very dangerous as they are very heavy and could potentially crush someone who doesn’t quite know what they are doing. I had my brother help me, a neighbor as a sort of spotter in case something went wrong, and incorporated the use of a transmission jack (they are meant for this purpose for a reason).

            I began by draining the transmission fluid. (Do NOT do this when the vehicle is hot, read on and you’ll fully understand).  I must tell you that on this particular model the pan does not include a drain plug and you must unbolt one side of the pan and let the fluid drain out that way. It is at that very moment, once one side is unbolted, that you realize this step is not going to be easy. Oil begins to drip down the sides of the oil pan and is easily manageable at first. As seconds pass you notice the drips’ pace begin to pick up as does the number of locations they are landing. Before you know it you have a monsoon of tranny oil dripping everywhere and you are running for a roll of paper towels. As you begin frantically ripping off sections of paper towels and try to place them under the drips you begin getting covered in oil yourself.

            This was just about the worst job I have done on a vehicle yet. Only about 50% of the oil made it into the drain pan, 15% on me, and the rest is on the ground. All I want to know is what were the designers of this thinking when they decided to omit a drain plug?! In any case I eventually got all the oil out, or so I thought. I will get back to that later though. (Picture: Tranny, Caption: You begin to realize how much of a disaster draining the tranny is going to be just as soon as you get the bolts out of the one side of the pan.)

After draining the tranny oil I removed the Torque converter/flywheel shroud. This can be removed by unbolting the 3 bolts on both sides and then the 2 in the middle.
 
Next I detached the front and rear driveshafts. I detached the rear by unbolting the the four bolts connecting it to the pinion in the back and then sliding it out of the transfer case. Have an oil pan ready as more oil will come out of the case when you do this. I unbolted the same four bolts on the front driveshaft and just let that hang down out of the way.
 
With the driveshafts out of the way I unbolted the 2 bolts to the starter and pulled it down and just set it on the frame rail where it would be out of the way.
 
Next I unbolted the Transmission Cooler lines using an open-end wrench and then wiggled the dipstick tube out of the side of the bushing and set it aside.
 
Also, before you remove the bell housing bolts you must remove the 3 bolts that attaches the flywheel to the torque converter.
 
 
Before beginning to unbolt the bell housing bolts from the engine you need to put a support of some kind under the oil pan on the engine.
 

Finally, unplug any wiring connections that will interfere with removing of the transmission.

With everything detached you can now remove all the bell housing-to-engine bolts. Do note that there are 2 bolts on the very top of the bell housing for which access is difficult. Also note that some of the bolts are dual purpose and hold brackets for wires or other things. You must first remove the bracket and then unbolt the stud (bolt/stud pictured).

I lost the pictures of the actual dropping of the transmission but let me tell you that it was very tedious and time consuming and by no means do you want to rush this. When you drop the transmission it is possible to leave the transfer case attached and drop it as a whole but this adds a substantial amount of weight and also makes the whole assembly lopsided as we discovered the hard way. We were able to successfully drop the heavy assembly down without causing any damage to the truck or ourselves, but I will never do it again as a whole. I will show detailed pictures of reinstalling the transmission and components to help fill in the gaps I had from the detachment stage.

Using our creeper we wheeled the tranny/transfer case assembly to the garage where we unbolted the transfer case. The transmission is now ready to be disassembled.

            The first stage of this project was not as difficult as I anticipated but did take a little more manpower and a lot more paper towels. I will began disassembling the transmission and once completed will post the next article.

Pro-Built Automatics
https://www.700r4l60e.com/
934 5th Street , Calimesa CA 92320
Attn: Dana - 909-795-1876
700R4 and 4L60E Transmission Specialists

Pro Torque
http://www.protorque.com/
1440 Church Street
Bohemia, NY 11716
(631) 218-8700
Custom Built Torque Converters

AAMCO Transmission
http://www.aamco.com/
1-800-GO-AAMCO
Transmissions and Complete Car Care Experts

 


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