Houston, we have a problem.....

[britlude]

looks like my gearbox is giving up the ghost...gotta in thru the diagnostics to work out just what but does Anyone know of an auto box out there? And if i were to be offered a flappy paddle box, would that need the later AT ecu and other mods? Very sad face

[NSXGB]

Bad luck Jon.
Man of your calibre could build yourself one.
Obvious recommendation would be to contact Dirk.
I'm only guessing but I'd put money on the fact that the F-Matic has a different control unit, or an extra one for the paddle control. Maybe a comparison of the parts diagrams could give you that info.

[AR]

Sorry to hear that, what oils were you running in the box?

[britlude]

Dirk says he has an early flappy paddle from a Very low mileage 1996.....

[AR]

If you can integrate it you might be able to get a proper set of paddles and different wheel. You will need a gear indicator too I think?

[jpspringall]

If you can integrate it you might be able to get a proper set of paddles and different wheel. You will need a gear indicator too I think?

Yep, the Gear Selector Clustor is slightly different as there a digit LED to show you the gear when in 'manual'

Would be interested to know if you do end up changing the steer wheel/paddle.

Though if you look for my previous post, the paddle is part of the combination switch rather than the paddle.

James

[britlude]

what i was aiming as was to find out if the flappy paddle box and the normal auto box are the same beast just with different ECU...

ie. are the boxes the same or is there extra hardware on the later auto.

it's looking more towards my box being rebuilt...

and looks like an expensive addition to my build thread.....

[sorepaws]

Ouch ! Ouch !

[Kaz-kzukNA1]

Hi, Jonathan.

Sorry to hear the news.
What kind of problem are you having?
Slipping CL discs or can’t even get into the gear?
Any flashing of ‘ D ‘ indicator?

Honda AT is quite different from other manufactures and it’s using multiple discs at each gear modules. These discs are submerged in ATF and the AT controller will let the discs to slip by controlling the oil pressure to achieve smooth shift up and down.

Because of this mechanism, eventually the discs will wear out.

In Japan, apart from Type-S and Type-R that were only available as MT model, AT was more popular than the MT among the Coupe and Targa models.

The very common failure mode on AT models in Japan is that the multiple clutch discs at the 3rd gear module worn out too far resulting in excessive slip and if kept driving, the dust from the discs will block the ATF strainer and eventually no longer be able to build up the oil pressure resulting in no gear selection at all.
Obviously, before getting to this stage, there is a certain sign of failure such as excessive slip at the time of gear change.

At this stage, I don’t know what kind of issue you have.
It could be internal AT box issue, input sensor, solenoid issue, etc.


Although the controller itself is different between the original and F-matic, the basic control (shift and lockup solenoids) is the same.
F-matic manual shift lever +/- sw is NO(Normally Open) type so without the lever module, it will simply do the full automatic shifting.
By the way, the lever module is very expensive...... Thought about using it for cruise control sw after replacing the steering wheel but gave up because of the cost.....

The manual gear number display on the dash is just the output from the AT controller with the voltage level of three wires so even without them, it won’t affect the AT control.

From hardware point of view, the final gear ratio was changed to 4.4 when F-matic was introduced until some point when it went back to the original spec so you will feel better acceleration compared to the original AT box.

I don’t know whether the oil pressure control software or the servo bodies are the same or not.

I’m afraid I don’t have enough experience to confirm whether it is a plug-and-play swap between the original and F-matic AT box.



If you are going to take the Gbox out by yourself and if you have the access to the spare box, you may want to challenge overhauling the existing one first.
The multiple discs and plates are not that expensive and that's what some of the NSX specialists in Japan are offering as one option for the owners with AT issue if there is no reasonably priced spare box available.

I have very limited experience with AT box but I think you need to be careful by following the specific procedure when stopping the engine before the removal of the Gbox and also specific procedure before/during the first fireup of the engine after the overhaul of AT box.


Any way, first thing first, you need to find out what kind of issue you have with possible failure code available or not.

Kaz

[britlude]

right.... thanks for all the offers and advice.

my box appears to have a hydraulic issue rather than an electrical/ECU issue. with the service connector shorted after a drive that experienced the issues, (and keeping the ignition on to prevent any AT ECU codes going missing, there are no fault codes displayed...

the symptoms are.... select drive, will pull away at light throttle until approx 2200 rpm then will start to slip and lose drive (either 1st gear losing 'grip' or second not engaging)... pull gearstick to '2' still the same, select '3' and no drive until the engine rpm drops to approx 1000rpm, then the gear will engage and drive fine. changing back to 'd' will cause drive to be lost, reverting back to '3' slips until the 1000rpm magic point is hit again, BUT with the road speed slower than when D was tried!

basically i have half of 1, all of 3, R works, and the rest are N!

hence it's not happy! the oil (dextron II as per usual) was brown, but not burnt (about 30k miles old) and the magnet trapped particles on the drain plug were super fine dust, no grittiness or chunks of shrapnel! nothing unusual in the sump...

i drained and changed the oil (which ironically i was going to do before silverstone) just to make sure, and it's still sick.

so the latest state of play is thus... i have a replacement second hand box in my garage now, picked it up this afternoon!

the plan being to fit this (time being an issue) and cross my fingers! there was no core surcharge, so i get to keep my box, then when the need arises i can have my original box rebuilt at my leisure and swap that back in.....

guess what i'm doing at the weekend!!!!