Gday guys and gals,

I've got a 96 TE Magna the ol' 2.4l with auto trans.
I've had the old girl for near on 10 years and she hasn't missed a beat.
BUT recently I have noticed that:
When cruising at a constant speed of say around 100-110kph, the gearbox "Flirts" between 4th gear and the overdrive, not noticible to feel, very smoothe, but can be seen in the RPM.
Has anybody got any ideas as to what this could be and if it is the start of some serious tranny problems?

Thanks in advance,

Richo

My TF 3.0ltr does the same thing, usually at around the 70km/h mark. Tends to only happen when the road goes from a flat to a slight incline. I think it's got something to do with the torque converter. I may be wrong. I don't think, however, that it's the first sign of ur transmission dying. Hope this helps.

I'd much more expect that at 70 kph than 110kph. Its related to the automatic problem of 'hunting' for the gears, where one gear revs too low and the other gear revs too high. Generally I believe the software in the trans is designed so it doesn't happen at standard speeds, that is, speeds of 60, 80, and 100/110. However, you also have 70kph zone and now 50kph in built up areas. Newer transmissions probably take those in to account as well, but at the time of manufacture of TE/TF/TH etc the 50kph in built up areas zone didn't exist. The learning nature of the gearbox doesn't seem to take this in to account either.

So, the hunting in a 70kph zone especially on a slight incline is normal, but I wouldn't expect it at 100-110. If you had to push the car a little more to respond than say, 5 years ago it could be related to more loss of performance than having to do with the gearbox as the gearbox also responds to throttle input. I have no idea whether a slightly worn TPS would have that symptom, but in the situation of you having the same throttle input hence the same airflow into the engine, the MAF sensors etc doing their proper thing, but the thottle position sensor thinking you are inputting more throttle then backing off... (as I said, no idea)!

Thanks for the replies,

Spoke to a couple of auto transmission service centres. Apparantly the gearbox has 2 stages (I assumed an overdrive feature) in not just 4th gear, but 3rd and one bloke seemed to think even 2nd. It goes 2nd, 2nd lock-up, 3rd, 3rd lock-up, 4th and then 4th lock-up.
Its the 4th gear lock-up and 4th that seems to be hunting, at times when it shouldn't in my case. It will kick down from the lock-up or even to say 3rd when tackling a hill at around 100-110kph, but it flirts around on absolutely flat ground with no throttle position change at all.
I have booked in for a trans service (Oil and filter) as it is well overdue and will see how that goes.
Poor old transmissions seem to be a bit left out in car maintenance, it seems that only when something goes a miss we pay a bit of attention to them. I do preventative maintenance on everything else (Motor oil and filter religiously, brakes, tyres, cooling system etc.) but neglected transmission. Hopefully its nothing major.

Richo

If you need the auto done, good time to do the power steering if you haven't had that serviced in a long time. Its one of the easiest service items to do yourself.

is it common to find that the power steering oil looks new after 190k kms if the car has only ever been on the highway?