Ok, so I had a few questions on my "shadetree transmission flush" and I thought I would share the basic procedure.
First of all, the UZJ-100's had different transmissions through the years and it is ABSOLUTELY IMPERATIVE that you look up your correct transmission fluid and ONLY use that specific type. Some use Dexron II/III, some use Toyota T-IV, and some use Toyota WS. THEY ARE NOT INTERCHANGABLE!
You will need:
- 12-qts (minimum) of appropriate ATF
- Hand Pump for fluid transfer (Amsoil sells one)
- ATF/Oil Catch Pan
- 5+ gallon bucket
- Vice Grips
- 14mm Wrench or Socket/Ratchet (trans pan drain bolt)
- 12mm Socket/Ratchet (skid plate bolts)
- 5mm Hex Wrench or Ratchet Bit (Check/Overflow Screw)
- 24mm Socket with long handle (Fill Port Plug)
- Oil Change Ramps for easier access to Transmission Pan and Fill Port
- Misc Rags for Cleanup
- Funnel
On the A750F 5-Speed Transmission, there is no dipstick, but there is a fill port and overflow "Check" port on the transmission body. If you have an A343* transmission, then you can skip any steps referring to the fill or check ports and just fill and check your level via the dipstick tube. It's still easier/cleaner to use the hand pump for fill rather than trying to pour the ATF into the tiny opening of the tube.
Remove front skid plates with 12mm Socket and Ratchet.
A750F:
I drove my truck up onto the ramps, put in park and set the parking brake, and placed the oil/ATF catch pan under the transmisison drain plug. If you have an A750* transmission, look on the driver side of the transmission housing, just rearward of the transmission pan drain plug up by the shift linkage to locate the 24mm Fill Port Plug. You will want to use the socket to remove this fill port plug FIRST. It has a "WS" embossed on the head. You can't miss it! Next you use the 5mm Hex Wrench to remove the overflow "CHECK" screw in the bottom of the transmission pan. LAST one to remove is the DRAIN PLUG from the pan.
Once you drain the ATF from the pan, then replace the Drain Plug and torque to 20 ft-lbs. Use the hand pump to transfer about 2.5-3 qts of ATF into the fill port (or down the dipstick tube for A343* users) until you get a tiny trickle of new fluid coming out of the "CHECK" port (A750F only).
Go to the front of the truck and use the vice grips to move the hose clamp from the DRIVER SIDE ATF HOSE going to the radiator. Pull the hose from the barb, place into the 5-gallon bucket. Adjust the screw on the vice grips and clamp them on the hose so that flow will be restricted somewhat and the vice grips will hang on the hose to weigh it down.
Now, go crank the truck. You will hear the ATF fluid squirting from the hose into the bucket. Now is the time to adjust the screw on the vice grips so that the flow is a small steady stream. You should drain 2-qts in about 15-20 seconds. Shut engine off at that time. If you hear the fluid "gurgling" or "sputtering", then it's time to shut the engine off!
Now, you have to go put more fluid in the pan. Transfer another 2-3 quarts (as much as you have removed via the hose/bucket) to the pan.
Start the truck and with your foot on the brake, move the gear selector through the entire shift tree at about 1/2-second intervals.
P-R-N-D-4-3-2-L-2-3-4-D-N-R-P
This will flush the old fluid from the valve body and replace it with new fluid. Be quick about is as you don't want the sump to run dry! Shut truck off.
Fill transmission pan again with 2-3 quarts and start engine again.
Repeat the above until you go through at LEAST 10-qts of fluid AND you get bright-red ATF coming out of the hose at the front by the radiator.
Once you've done that... Remove the vice grips from the hose, and put the hose back on the barb of the radiator. Now put the clamp back in place. Check the fluid level by topping off via the Fill Port until it flows from the "CHECK" overflow port. At that point, you will want to screw the check screw into it's hole and replace the fill port at the top of the transmission housing - finger tight is OK on both for now.
Start the engine, back the truck down off the ramps and let it idle for at least 5-min. With your foot on the brake, cycle the gear selector through the entire shift tree several times, with at least a 1-2 second interval for each gear. Shut off engine.
Check transmission pan temperature with IR gun or other means. It should be between 115°F and 130°F. If not in the specified range, then either allow to cool or go for a short drive to get in the desired range. Although this is not SUPREMELY important, you should heed the advise so that optimum fluid level is achieved in your garage using the DIY procedure.
Now that you have the transmission cooler and valve body full of fresh fluid and the truck is on LEVEL ground (truck RUNNING, wheels chocked, in Park with parking break on) you will need to get back under it and remove the CHECK overflow screw. If fluid drains from the overflow port, catch fluid and allow to drain until it stops. Replace screw and torque to 15 ft-lbs. Torque Fill port to 15 ft-lbs also.
If no fluid drains from the CHECK overflow port, then remove the Fill Port Plug and add fluid to the pan until it drains from the overflow port. Once fluid is "topped off", then install screw and plug and torque as described above.
Wipe down transmission pan of any residual ATF so you can see any leaks should they occur.
Now, take the truck for a short test drive, shifting through the gears, and return to garage. Check underneath for any leaks at drain, fill, and overflow plugs. Check for leaks at hose barb at radiator. If no leaks, replace skid plates and YOU'RE DONE!
THIS BULLETIN from Toyota shows the procedure for dealerships to basically accomplish the above and charge you $$$!