This seems to be relatively common on these BXMA transmission. My story is as follows:

I bought a 2002 Civic with a bad transmission. It would not move in R or D but would move forward in the lowest gear for about 1 minute before it completely refused to go any further. I expected a clogged strainer. I pulled the transmission, replaced the strainer with the new design and rebuilt the cluches while I was there. All of them looked good except for the 4th clutch pack which had some burn frictions and steels. I replace them with new, put it back together and installed the transmission. I got no reverse and a big flare shifting from 1-2. I didn't drive it more than that. I put the car back on jack stands and unplugged one of the linear solenoids that are supposed to regulate line pressure. When unplugged, the transmission goes into reverse no problem. You feel the "clunk" that you always feel putting it into reverse if one of the solenoids is unplugged. If I plug it back in, no reverse, no clunk. In fact, the driver's wheel moves in the forward direction when both solenoids are plugged in. I replaced the solenoids with a couple of units from the junk yard. All have the right resistance on the coils. All click. All move the piston on the solenoid. I've gone through the wire checking procedures from the FSM for shorts to ground and continuity. In other words, the wires to the solenoids are good. I did not have the right adapter to check the line or clutch pressure. (If someone knows which adapter is needed, I'd appreciate it.)

I've pulled the transmission again and am in the process of doing a deeper rebuild. I've replaced the accumulator o-rings and am tearing into the valve bodies. The only thing I've found so far that isn't right is the 3-4 orifice control valve in the secondary valve body retracted when I pushed on it, but the spring did not push it back out. I've cleaned the valve and its bore and it seems to be working fine. The other valves in the secondary valve body move fine with no sticking. They are under greater spring pressure. I plan to pull the other valve bodies and go through them as well, but haven't been able to get to them yet.

My question is what am I looking for? Does this sound like a valve? I thought I may not have installed the reverse shift fork correctly, but it worked by hand. My theory is that the linear solenoids must modulate or regulate the pressure being applied to the shift fork or the 4th clutch pack and that for some reason there is not enough pressure present when they engage. I'm guessing that without their involvement, the pressure from the pump flows directly to wherever it flows and overcomes whatever restriction or problem is present. If I find a stuck valve, great but based on this set of facts, does anyone have a good guess as to what's wrong?

Thanks.

 

Vehicle moves in
D4, D3, 2, and 1,
but not in R (or
moves forward
in R)

Shift fork stuck?
Modular valve defective?
Reverse Clutch Pressure Cintrol (CPC) valve defective?
4 th accumulator defective?
4 th clutch defective?
Reverse gears worn or damaged?

Check the line pressure and 4th clutch pressure.
Check for a missing shift fork bolt on the shift fork shaft.
If the ATF strainer is clogged with particles of steel or
aluminum, inspect the ATF pump. If the ATF pump is OK, and
no cause for the contamination is found, replace the torque
converter.
Inspect the reverse selector gear teeth chamfers, and inspect
the engagement teeth chamfers of the countershaft 4th and
reverse gear. Replace the reverse gears and the reverse
selector if they are worn or damaged. If the transmission
makes clicking, grinding, or whirring noises, also replace the
mainshaft 4th gear, reverse idler gear, and countershaft 4th
gear.
If the 4th clutch feed pipe guide in the end cover is scored by
the mainshaft, inspect the ball bearing for excessive
movement in the transmission housing. If the ball bearing is
OK, replace the end cover as it is dented. The O-ring under the
guide is probably worn.
Replace the mainshaft if the bushing for the 3rd and 4th clutch
feed pipes are loose or damaged. If the 4th clutch feed pipe is
damaged or out of round, replace the end cover.
Inspect the clutch piston, clutch piston check valve, and Orings.
Check the spring retainer for wear and damage. Inspect
the clutch end-plate-to-top-disc clearance. If the clearance is
out of tolerance, inspect the clutch discs and plates for wear
and damage. If the discs and plates are worn or damaged,
replace themas a set. If they are OK, adjust the clearance with the clutch end plate.

This was taken from a Honda Odyssey service manual with a 4-speed trans. Hope it can help in some way. You deserve to get that trans back to life with all that work...

 

Here you go

 

Did you soak the clutches in ATF before you installed em?