4L60E Repair Guide - Disassembly

TRANSMISSION DISASSEMBLY

Place the transmission on a sturdy workbench.

Remove the transmission mounting bell housing. This is not a task for a bargain tool. The Torx fasteners used to assemble the bell to the trans have a T-45 recess, and are not only torqued to a high level but have had adhesive applied. Beyond that, they may have suffered seizure and galling upon installation or since, and will require significant torque to break free. Use a good quality, undamaged Torx driver bit. Penetrating oil applied well in advance and heat on the case areas surrounding the bolts will make the job much easier. This one step can turn the project into a nightmare if not done successfully.

Remove the transmission oil pan and filter.

Remove the wire harness and main electrical connector socket. The socket has four locking tabs which need to be compressed inward to allow the socket to be pushed into the transmission.

Remove the TCC pressure signal solenoid (if equipped) retaining clip, then slide the solenoid from the valve body.

Remove the TCC solenoid retaining bolts and slide the TCC solenoid valve out of the pump body.

Compress the pump pressure relief valve cap inward slightly against the springs, then remove the valve snap ring.

Remove the valve body, reverse boost spool, both springs, and internal pressure control/regulator valve spool. The entire pressure control and boost valve can be left in place until the pump is removed, but removing it now will allow more oil to drain out while the bench is already full of contaminated oil.

Remove the valve body bolts and the lower valve body. Secure the work area so that all seven of the check balls will be contained when removing the plate. Take care to release the lower separator plate gasket. Even if you plan to replace the gasket, it will be easier to remove the gasket in one piece than to clean off all remnants of the gasket from the valve body or separator plate.

Remove the 2nd gear accumulator bolts and accumulator.

Remove the three bolts from the stamped steel plate near the left rear corner of the valve body, remove the three accumulator body bolts, then remove the separator plate. There will be at least one additional check ball to capture when the plate is removed. The second check ball in the upper valve body should be retained in a cage assembly, but may be loose. With the separator plate removed, remove the accumulator spring.

Remove the pump housing bolts and carefully pry the pump out of the front of the case. There are pump pullers designed specifically for this purpose, but a careful use of a large flat bar will coax the pump and its sealing ring out of the front cavity bore with no damage. Prying between the pump and input drum and/or the gaps at the bottom of the transmission case should get it moving forward. Be careful to avoid damage to the pump gasket and case machined surfaces.

Remove the band anchor pin from the upper valve body area. A strong magnet works well for this. This should relax the band adequately to allow removal of the reverse input drum assembly.

On the exterior of the right side of the transmission case, clean the area surrounding the 2-4 band servo cover. Compress the outer cover for the 2-4 servo inward, then remove the lock ring. Slide the cover and servo assembly outward.

Remove the input shell and drum/clutch assembly. Pull straight outward and support the weight of the assembly as it disengages from the reaction shell and input planetary set.

Remove the band. These parts should now be sitting on the bench:

Remove the yellow shaft lock retaining ring from the output shaft, then remove the input sun gear. You should also be able to remove the VSS or speedometer thimble, tail shaft housing (if equipped), and output shaft at this time.

Remove the input planetary set as an assembly.

Remove the reaction sun shell. There is a thrust washer visible on the front, and another behind the shell which should be attached to the reverse sprag hub. Be aware that it may fall out as you remove the shell and that this is no cause for alarm.

This reaction sun gear spline had lost the rear retaining ring from the groove and showed some spline damage - The spline does not fit new sun shell hub easily.

Remove the large lock ring holding the low-reverse clutch support, then lift out the support plate. There is no spring force behind the support, so the lock ring should disengage easily.

Remove the low-reverse (reaction) planetary assembly as a unit.

Remove the low-reverse clutch stack and low-reverse planetary ring gear, then the support plate behind that. Remove the planetary ring gear support lock ring.

You should now be looking at the low-reverse clutch apply assembly. Compress the low-reverse clutch spring pack with a suitable tool, then remove the retaining ring from the hub. Relax the compression on the spring pack and remove all the parts. The case should now be essentially a bare casting, other than some seal rings, bushings, and the parking pawl and shift linkage remaining in the case. This is an appropriate time to clean the case exterior thoroughly in preparation for assembly.

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