How to rebuild a RE4R01A automatic transmission. This is actually more along of a teardown procedure than a rebuild at the moment as I am inspecting the internals for damage for accessing value/cost of repair vs picking up a newer (Xterra) transmission. I'm also see if the internals can be upgrade to the "heavy duty" version of the later Xterra transmissions. Keep in mind, I'm not a professional tradesman. Just your typical average joe who likes take things apart. Pulling the guts out is a no-brainer and you really don't need a FSM for it. Where the FSM comes in handy is when you start taking apart the valve body. locations of the pins, valves, springs, spacers, washers, O-rings, seals, and different lengths of bolts is very critical so It's best to keep a "map" of where things go. Also it helps to have already taken it apart before LOL.
If you manage the get your input shaft jammed inside the torque converter, it's pretty likely you may have damaged your torque converter. :roll:
Remove the torque converter. Your input shaft should still be attached inside your transmission. Drain the fluid out of your torque converter. Remove the input shaft by pulling it out. It kind of snaps/locks inside the transmission with a detent. Remove the bellhousing. It's held onto the transmission by some 14mm bolts. On mine it looks like some sealant was use on the bolt shoulders to prevent fluid from leaking. Also, on mine, sealant was used on the oil pump so when I removed the bellhousing it came off stuck to the bellhousing. This is the backside of the oilpump stuck to the bell housing:
needle bearings on the back side of the pump:
Make a note of the rubber seals here in the grooves. They are split seals so make sure you do not loose them or forget to put them back on.
Anyhow, if you're 2wd or 4wd, you'll need to remove the tailhousing/adapter to get access to the output shaft.
Make note of how the parking pawl lock, spring, pin, and spacer are oriented. Remove and keep them in a baggy.
Now remove the parking gear. It's held in place by a snap ring. You may need a small flat blade screw driver to help get it out along with your snap ring pliers. I had to but it could be that I'm using some cheap stuff. Once the snap ring is out, you can pull out the parking gear. Behind the parking gear is a small thin caged needle bearing. You'll see a lot of these later on. Remember the orientation of the bearing.