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3rd gear's gone on auto trans


Experienced Member
19 September 2004
:frown: Just as suspected my 3rd gear's shot. Normal shift from 1st to 2nd then to 3rd.... nothing there, it'll just rev up with no power to ground. Was told possible reasons, one of it I found out the last owner used one of those aftermarket auto trans oil, not the recommended Honda's :mad:

Well, my mechanic's sourced out an exchange programme for my trans, don't have the full details just yet but they're offering strengthen carbon/steel internal and upgraded torque converter this all come with warranties- sound expensive... we'll see, I guess there goes my GT-One SuperFour exhaust for another couple of months. If all goes well hope to get the car back on the road about a week or two. Will update ...
I'm calling bogus on the oil. The entire tranny either slips or it doesn't.

I have rebuilt many automatic transmissions, not for the NSX though. There is a big test harness that makes diagnosis fairly easy, call around to a shop to that has one....it is probably the same for the Legend.

The fact that the tranny works in two gears, but not three suggest a "control" problem to me.

Have them tighten up the 3'rd gear band. (actually, have them torque all the bands down). The band might be shot, but if it happened suddenly w/o warning: I suspect an actuator.

Test the actuator for 3rd gear---my first guess is this is the problem. Make sure it is getting the command to engage. If it is: bench test or swap actuators.

If you don't deteremine if you have a control problem vs a mechanical problem chances are you will continue your current problem after changing out the mechanicals.

Don't let them R&R parts w/o diagnosis. This stuff isn't that hard: they are just being lazy.

I've actually changed the oil back to Honda's recommended,problem still persist. They did mentioned total loss of pressure in 3rd probably because of the acuator. I'll talk to the shop again and see if they can do a proper dignosis.Thanks for the info.
I have the same problem. I had the transmission rebuilt, the problem went away but soon returned after around 10k miles. I suspect that it is an electrical or control problem. Let me know how things turn out.
ive never been in an automatic nsx transmission but have rebuilt numerous honda automatics which are very simular in the way they work and are made. There should be a flow chart in the manual for diagnostic purposes. That being said i would bet that it is a problem with the third clutch assembly ie blown piston oring or even a clutch drum/hub problem. If it were a control problem when it goes as far as slipping or even losing a gear there is internal damage. For the most part automatic trans work is easy work but really needs a competent honda trans. guy doing it and taking the time to find out the cause of any damage done to the internals instead of just replace the damaged parts. Start with taking all pressures before trans removal. Ive seen bad shafts to bad bearings to faulty clutch hub design cause clutch failure in the honda automatics due to the failed parts coming apart and contaminating the trans with debris and cloging controls/solenoids.
So IsR is the problem fixed now? Where did you sent your car to? I might want my trans to be checked. It doesn't shift smoothly.:frown: