This how to describes how to change the Solenoid/Pressure Switch Assembly, a.k.a the solenoid pack on the 42LE Transaxle.
Although a 2nd gen is shown, the exact same procedure applies to 1st gen LH cars as both generations used the 42LE. Early shop manuals may refer to this transaxle as the A606.
The solenoid pack controls the the routing of transmission fluid via solenoid valves controlled by the TCM. This is the electronic component of the valve body which allows the TCM to shift the gears electronically. When it fails, shifts may become weird and the transmission will likely enter limp mode. This gives DTCs P0700 (transaxle control fault) and often P1776 (solenoid latched in low/reverse)
P1776 is the most common fault code but this code cannot be obtained using the key dance trick, a scanner capable of reading the TCM must be used. On my car, a trip to an auto parts store was enough, the little hand held courtesy scanner revealed P1776 without a trip to the dealer.
Difficulty Level: Medium
Time: 3.5-5.5 hours
Two jack stands and two jacks or wheel ramps
3/8" torque wrench (click type strongly recommended!)
3/8" drive extension (4-6" long is ideal)
3/8" drive 10mm 6 sided socket
3/8" drive Torx T25 socket (or 1/4" drive socket with 1/4 to 3/8 adapter)
Flat head screwdriver
Thin putty knife
Shop Supplies & Parts:
New transmission filter
Solenoid pack (duh!)
5-8 quarts of ATF+4 Transmission Fluid (I needed 7)
Oil Resistant RTV Sealant (Permatex Ultra Grey or Ultra Black)
Roll of shop towels
Quick evaporating solvent (denatured alcohol is OK)
CLEAN pan to place the valve body in
CLEAN non linting cloth
General purpose cleaner/degreaser
Assistant to hand you tools and read this how to or the FSM
Beverage of choice
Disconnect the battery. (the PCM/TCM need to be reset)
Raise the vehicle on jackstands, ramps or a lift. DANGER! NEVER WORK ON A CAR SUPPORTED ONLY BY A JACK!
Disconnect the transmission range sensor cable. This is the large connector near the shift lever. Use a flathead screwdriver to unlock the locking tab before attempting to disconnect the electrical connector.
Disconnect the shift cable from the shift lever. The cable is connected via a bushing that fits snugly over a pin on the shift lever. Push it upwards to remove.
With the cable disconnected, turn the shift lever clockwise until it stops. This disengages a mechanism on the valve body and allows it to be removed.
With a 10mm socket and 3/8 ratchet loosen the bolt on the shift lever and lift the shift lever off of the shaft.
With a 10mm socket, loosen the bolts on the transaxle pan. Leave one side loosely attached so fluid drain can be controlled. (be prepared for a mess!)
Separate the transaxle pan from the transaxle by inserting a thin putty knife or similar tool in between the pan and transaxle to break the RTV seal. Carefully pry apart if necessary.
Allow transaxle to drain.
Clean the magnet in the transaxle pan so it is free of metal shavings.
Clean the old RTV off the transaxle pan and with soap and water, clean the metal shavings from the pan. With a plastic tool or your fingernail, remove the old RTV from the transaxle itself. DO NOT use a metal tool on the transaxle, the aluminum case is easy to gouge. Clean both mating surfaces with a non residue solvent and allow to dry.
Place magnet back into the pan between the three dimples.
Remove filter. It may be necessary to use the T25 socket to remove one of the clips. Make sure the old filter O ring is removed as well. The new filter should include a new O ring.
Prepare a clean pan to place the valve body into. CLEANLINESS IS ESSENTIAL!
CAUTION! When the valve body is removed, the Overdrive and Underdrive accumulator pistons and springs will fall out! DO NOT allow these to hit the ground. Clean the accumulator piston with a non residue solvent and dry with compressed air or canned gas. DO NOT use shop towels to dry them.
The pistons, seals and springs are identical for the UD and OD accumulators and the pistons are installed with the open side facing the valve body. (piston face goes upward). The small spring is nested within the large spring.
With a 10mm socket and 3/8 ratchet remove the valve body bolts and remove the valve body. (again, beware the accumulators!)
Place the valve body and accumulators into the clean container.
Using the T25 socket, remove the four solenoid to valve body bolts.
With a suitable non residue solvent and a CLEAN non linting cloth, wipe off the metal shavings that may be present on the valve body top plate. Verify that the surfaces are clean.
Turn the valve body on its side and allow the fluid to drain. More metal shavings can be expelled this way.
With the 3/8 torque wrench and T25 socket, install the new solenoid pack and tighten the four bolts to 6 Nm (35 in-lbs)
Position the accumulator assemblies on the valve body plate so they will slide into the correct location when the valve body is reinstalled. Push the valve body into place and tighten the valve body bolts to 12Nm (105 in-lbs)
using the 3/8" torque wrench and 10mm socket.
Place a 1/8" bead of oil resistant RTV along the edge of the transaxle pan and around each bolt hole. Install the pan and tighten the bolts to 23 Nm (17 lb-ft)
Reinstall the shift lever, tighten the bolt and rotate the lever anticlockwise until it stops. The transaxle will then be in park and you can reattach the shifter cable and transmission range sensor wiring.
Lower the vehicle.
Reconnect the battery.
Wait 30 minutes to allow the RTV to set before adding the ATF+4. After 30 minutes, add 5 quarts of ATF+4 and start the vehicle. Allow the vehicle to idle for 5 minutes to allow the vehicle to warm up and to allow the PCM to fine tune the idle. Run the car through each gear while applying the brake (dont try to drive!) and then put it in park.
With the engine still running, check the fluid level and add as necessary. If the dipstick is dry, add a whole quart otherwise add in half quart increments to prevent overfilling.
Test drive the car at a variety of speeds and acceleration levels to ensure everything is normal. A few shifts may be odd as the TCM learns your transaxle characteristics.
Enjoy the $400 or so you saved by doing it yourself!
An assistant is useful....no matter how goofy he may be
Me and the 300M Special
Take the valve body to a clean location to work on it...mom's kitchen is ideal.
New solenoid pack
Unbolting the solenoid pack
Solenoid pack screen....beware the hidden ATF in the valve body, keep it in the pan!
Very fine metal shavings that accumulate....get these out before they find their way into your new solenoid pack.
An alcohol soaked cotton ball will do in a pinch to wipe off the shavings...microfiber would be far better.
This is what it will look like after you have cleaned it.
Using a torque wrench to install the new solenoid....
Accumulator piston. Note the sealing rings and the machined groove.
Springs are inserted into the piston. Install this end of the piston down (towards the valve body).