91 Automatic Transmission Issue

[terencekho]

Hi Guys,

I am looking for some advice.

I am getting some issues with my auto gearbox,

1) The car jerks when shifting up thru the gears, however there are no problems when downshifting. Jerk as in hard/harsh engagement of the new gear.
2) Once in a while, there seems to be clutch slippage. The engine will rev up when trying to shift up before the next gear will engage.
3) This happens at any traveling speed, doesn't matter slow or fast.

My mechanic had advised changing the filter gaskets for the Shift solenoid and lockup solenoid, which i did, but it did not solve the problem.

The next thing I did, was have the gearbox re-built with parts from Alto from the USA, but done locally in my country. The mechanic had said the clutch was worn.

However, after the rebuild, the gearbox still has the same issues.

Recently, it was mentioned to me, it might be due to the actual solenoids itself, due to the age of the car. However there are no error lights and the D light isn't blinking.

The gearbox has 3 solenoids - Lockup, Shift and linear. From my limited knowledge, it seems the linear solenoid, might be the culprit.

Has anyone experienced this issue and managed to solve it? Should I replace all 3 solenoids, or will replacing only the linear solenoid work.

Any advice or knowledge is greatly appreciated.

 

[Old Guy]

I have no experience with the automatic; however, as a first suggestion have you downloaded a copy of the service manual from the NSX Wiki for your model year? You might want to look at the trouble shooting and diagnostic procedures in the portion of the manual dealing with the auto.

 

[ofdlt10]

automatic transmission

contact pat at level 10 transmssions in n.j.
he's very familiar with our cars.

(973) 827-1000

mine is currently there being rebuilt. he's the only place that has clutches and gaskets for our automatics. he also rebuilds the torque converter.

this is my third trans.

 

[riddl3r]

This is your 3rd transmission? Wow! How have you survived? Have you always rebuilt? Is this the first time going with level 10? Have you ever just considered a 5spd swap? How many miles does your car have on it? Have you noticed any patterns or mileage when the transmission goes out? How often do you flush the fluid?

Sorry for all the questions. 3 transmission changes is concerning as I have an auto that I plan to daily.

contact pat at level 10 transmssions in n.j.
he's very familiar with our cars.

(973) 827-1000

mine is currently there being rebuilt. he's the only place that has clutches and gaskets for our automatics. he also rebuilds the torque converter.

this is my third trans.

Sent from my Pixel using Tapatalk

 

[ofdlt10]

automatic transmission problems

hi,
text me your phone number and i'll call you. the explanation is really extensive and a conversation would be quicker.
my # is 407-463-8686

regards,
roger

 

[drew]

It is can be difficult, time intensive and often requires special tools (or homegrown ones) to properly diagnose an automatic transmission.

It is often not worth a shops time at $150/hr or $5k tools to do much other than to throw parts at it.

I've rebuilt my share of automatics, it is not hard: it is an exercise in organization and cleaniness. Diagnosis can be hard.

The auto NSX is just as reliable as any other Honda product. Which is usually awsome. I find that the NSX auto is pretty darn nice too. However, there is nothing special about the NSX transmission that does not apply to the Legend or whatever...so troll those forums too.

Generally if the fluid is not burnt I do not condemn the clutch packs.

If no chunks of metal then you should presume the gears are good.

Now the hard part: control diagnosis.
It does sound like a solenoid or servo.

You can test the solenoids by bench testing, tapping into the harness to watch the voltage (with long leads into the car so you can observe while driving) and you could test pressure with a gauge.

It can get messy, expensive, and time consuming to diagnose...which is why you may just want to throw some parts at it first.

Throwing a whole transmission at it without dealing with the control system is a bit extreme if the fluid is good.

 

[terencekho]

Hi, thanks for your advice. Since my last post, I have replaced the solenoids, and that has not solved my problem.

The jerkiness is still there.

The mechanics are guessing that it might be the Auto Transmission Control Unit or it could be the valve bodies in the transmission.

I have not decided what to do as a next step yet.

 

[britlude]

if you get the symptom, jump the blue test connector BEFORE you switch the ignition off... mine had an issue but didn't save it, only showed via flashing the D if the diagnosis terminal was shorted before the AT controller is switched off....