Gearbox issues, help!

[Bullet]

Hello Saab fans,

I need your help again.
My car (1996 NG900 Turbo automatic) started to behave badly, especially the gearbox. The last year or so, it started to change gears a bit rough, especially from 1st to 2nd when cold. I changed the oil but it's no use, the changes are still rough.
Another problem with it, when the engine is cold and I stop at the lights, for example, if I brake sudden, the engine almost stalls, and sometimes it does stall. It seems to me that it doesn't disengage the gear, it remains stuck or something.
And finally, I have gearbox oil in the coolant system. I read on some sites that the gearbox oil pipes connect somehow with the radiator for the engine coolant, is that true ?

I visited several mechanics, and every single one told me that I need a new gearbox, or scrap the car because it's not worth the effort, moneywise.

What do you think is wrong with the gearbox ? Do you know some second hand one for sale ?

Any response is appreciated.

 

[knuts]

And finally, I have gearbox oil in the coolant system. I read on some sites that the gearbox oil pipes connect somehow with the radiator for the engine coolant, is that true ?

Yes. Your gearbox, in that case, has to be disassembled and repaired. Or you find a used one. If most of the the car is fine, it should not be wrong, to put the money in it - my opinion

 

[joerg augustin]

Another problem with it, when the engine is cold and I stop at the lights, for example, if I brake sudden, the engine almost stalls, and sometimes it does stall. It seems to me that it doesn't disengage the gear, it remains stuck or something.


Typically, as long as you are in pos. D, 3,2,1 the tranny always is engaged and the slip to allow the engin still to crank, e.g. when stopping, is realised by the "Drehmomentwandler" (sorry don´t know the english word). This is thing sits betwen the engine and the tranny. So in case the engine stalls, I would imagine that there is something broken with this. You can disengage the tranny by switching to "N". Give it a try and see if the engine still stalls. This Drehmomentwandler is also in charge to buffer the difference in RPM when the tranny switches from one gear to the other. The tranny as such does not slip, it´s a meachanical coupling of kogg wheels that are actuated by hydraulic valves. In any case, I would think you will need to disassemble the system and have at least the Drehmomentwandler changed. I would not go and just have the tranny changed or repaired without looking seriously to the Drehmomentwandler.

 

[REDxFROG]

Gibts auf Saabcentral keine Hilfe? Und du suchst nach "torque converter". Jetzt wo du es liest, ist es sicher offensichtlich.
So niedrige rpm beim anhalten kann natürlich viele Gründe haben. Der soll das mit N echt mal machen.. dann weiß er auch woher das ruppige schalten kommt.

[video=youtube;-SVkgl0gyJ4]http://www.youtube.com/watch?v=-SVkgl0gyJ4[/video]

 

[Bullet]

As if the gearbox issues weren't enough, now I have another one aswell.
When I turn the ignition on, the dashboard lights dont't turn on as bright they should, they are very very dim, and the gauges remain down. If I fiddle with the key in the ignition, teh dash sometimes works as it should, but that happens less and less.
Finally, I drove the car with no lights on the dash, and it was very strange, it lacked power, and in D (drive), it was like a slipping clutch, I had to step hard on the gas pedal just to drive off. Now, I don't know if this has anything to do with the gearbox issues or it's just the ignition switch, or the ignition barrel. May be they are all with fault ?

I have owned the car for the last 4 years and, despite it's age, it was very reliable but it seems age has finally caught up with it :(

 

[REDxFROG]

Don't you have any SAAB car shop nearby? Maybe just to let the car get checked by professionals without obligation.
They can most likely tell you pretty quickly what's wrong with it.

The "slipping clutch" you have noticed might have just been the "Drehmomentwandler" --> "Torque Converter" as mentioned by joerg augustin.
I don't know much about automatic transmissions but from what I have seen in the video this "TC" works roughly like the clutch in manual cars.
If there's a malfunction with it, you'll either get no force towards the gearbox or not enough (slipping).
Also when changing gears, the "TC" might not work quick/precise enough, leaving the gearbox connected to engine and not matching the rev. which results in rough shifting.

So you are saying sometimes you have to drive the car without a working speedometer at all, or does it sometimes re-activate while driving? My father sometimes had that problem, but I think when the speedometer turned off - the lights from the dash also turned off.

 

[Bullet]

The closest Saab shop is about 140 km away.

The slipping thing only happens at the same time the dash lights are out, so I'm guessing the 2 problems are related somehow.
I'll try to find an ignition switch to swap with mine to see is this is causing the dash lights problem, and also post a video, maybe it helps.

So you are saying sometimes you have to drive the car without a working speedometer at all, or does it sometimes re-activate while driving? My father sometimes had that problem, but I think when the speedometer turned off - the lights from the dash also turned off.

The dash lights and speedometer/rev meter occasionally re-activate when driving the car. And yes, when the needles are out, so are the lights.

 

[aero84]

Where are you? If in Germany, you might also want to check our "Hilfeliste" - a list with workshops that according to the experiences of the forum members offer good work at a reasonable price.


Your gearbox problem sounds similar to mine (9000, gearbox ZF 4hp18) : when approaching a traffic ligt, the car sometimes will almost stall, if cold stall. Often, the engine will fight back, raising rpm , be forced down again below idle, fight back etc,
This only occurs in gears 3 and 4. Downshifting manually to "2", "1" or even to "N" will instantly resolve the problem. Seems like the gearbox is stuck in one of the higher gears...
Now, when I approach traffic lights, intersections and the like, I will downshift manually once rpm get down to about 1000-1200, avoiding the problem.

I attribute the problem to neglected maintenance by the previous owners: when we changed gearbox oil, the "oil" draining from the gearbox had almost nothing in common with the slightly red ATF we know, but instead resembled black, slow moving tar. My guess is this has clogged the valve/steering box.

It is possible to clean it. A ZF service station will disassemble the steering box, flush the gearbox, clean the steering box and reassemble it for about 400€. Now let's hope the rest of the gearbox is ok...

 

[majoja02]

mein englisch ist leider sehr mies, vielleicht mag jemand übersetzen, denn der google übersetzer ist nicht der hit.

Ich lese im Text des TE das ihn folgende fehler aufgefallen sind oder er von gelesen habe.

1. Wasser im automatiköl durch def kühler......recht selten dieses Problem
er möge einfach mal eine geruchsprobe am Automatiköl peilstab machen....riecht es verbrannt?

2. Auto schaltet eher unwillig und unkontrolliert.......ölstand überprüfen bei eingelegten gang mit zweiter person.

3. und ich meine das hier der fehler steckt, masseproblem bzw seine Batterie..........batterie überprüfen am besten Tauschen wenn überaltert.
..nur wenn batterie gut und er nach wie vor unterschiedlich helle armaturenbrett beleuchtung(kontrolleuchten) hat möge er die Kontaktplatte unterhalb vom Zündschloß wechseln oder überprüfen lassen.

mein pers. Tipp wäre diese kontaktplatte unterhalb vom schloß
masse wird nicht oder schlecht geschaltet, typische zeichen unwilliges anspringen, stottern beim fahren,getriebesteuergerät hat nicht genug spannung bzw bekommt falsche daten usw.........

weiterer Tip der schaltlagensensor, aber dann würde der wagen zeitweilig garnicht anspringen(sich nicht startenlassen).

vielleicht kann jemand das übersetzen....danke

 

[knuts]

vielleicht kann jemand das übersetzen....danke

Versuch, sinngemäß:
1. Water in the oil of the automatic gearbox is an unusual problem. Does the oil at the dipstick of the gearbox smell burned?
2. Is enough oil in the gearbox? In order to test the oillevel in the gearbox a 2. person puts the gear selector on "D" while the engine is running. Now look at the dipstick at the marks for max, min - cold, warm.
3. I think here is the problem - an old batterie. Please test it or put a new one inside. If the batterie is perfekt, test or change the contactplate under the ignition lock.
My private tip would be this contactplate under the ignition lock.
Ground contact is not or badly switched, typical signs of wear are unwilling starting, stumbling engine whlie driving, undervoltage of the gearbox's steeringbox, wrong dates are carried forward

 

[Bullet]

Where are you?

I live in Sibiu, Romania.
Is there a way that I can do some kind of power flush myself ?

Versuch, sinngemäß:
1. Water in the oil of the automatic gearbox is an unusual problem. Does the oil at the dipstick of the gearbox smell burned?
2. Is enough oil in the gearbox? In order to test the oillevel in the gearbox a 2. person puts the gear selector on "D" while the engine is running. Now look at the dipstick at the marks for max, min - cold, warm.
3. I think here is the problem - an old batterie. Please test it or put a new one inside. If the batterie is perfekt, test or change the contactplate under the ignition lock.
My private tip would be this contactplate under the ignition lock.
Ground contact is not or badly switched, typical signs of wear are unwilling starting, stumbling engine whlie driving, undervoltage of the gearbox's steeringbox, wrong dates are carried forward

1. The gearbox oil smells normal and has that red-ish color, it's suppose to have.
2. The level is fine, just checked earlier today.
3. The culprit for the dim lights problem was the ignition switch.
I managed to secure one from a friend who used to own several NG900s. The job of changing it, however, is not an easy one. It took me about 4 hours despite the fact that earlier this year I changed the heater core seals, another mammoth job.
Instructions on how to change the ignition switch can be found here:

http://pages.infinit.net/mlbriand/saab/heatcore.html

and here

http://photo.platonoff.com/Auto/20070617a.Saab_NG900_Shifter_Housing_Removal/

Still have the gearbox issue, but this success is very good for moral.