Hi,

First off, I own a 1997 TF Magna with 230,000K on the clock. The transmission seems a bit jerky in the 50~80KM/h range. Generally it will automatically change gear at the 75~80KM/h range, but when it does so it will rev out another 500~750RPM, and the car will lurch/jolt. The transmission was done at 198,500KM. I've checked the transmission fluid and its within the optimal level. Also, ATF is meant to be a red/cherry colour correct? Are the magna transmissions just a bit jerky in that range? Should I get a transmission expert to run a diagnostic on it?

Secondly, how much would I be looking at when replacing the timing belt + new tensioners etc? I haven't had it done for over 100,000KM, but there's its not making the usual screeching noise that timing belts do.

Thanks.

The jolt into 4th is most likely a sticky solenoid in the valve body. Because the solenoid can't open or close fast enough to route fluid to where it needs to go to get the planetary gears to select 4th ratio, the engine is still accelerating when the gearchange finishes.

The jolt into 4th is most likely a sticky solenoid in the valve body. Because the solenoid can't open or close fast enough to route fluid to where it needs to go to get the planetary gears to select 4th ratio, the engine is still accelerating when the gearchange finishes.

Thanks for the reply.

I forgot to say in my original post, if I am accelerating up to 80+KM/h and I back off the accelerator at the 70KM/h mark, the gearchange is a lot more smoother and there's no 'rev out'. Not sure if this changes anything but the more info the better.

Is a sticky solenoid something I should get fixed ASAP? Is my gearbox likely to blow if I don't? Also, could you possibly explain a solenoid in more detail for me? All I really know about them is that they tell the gearbox to change gear, basically?

Also, if a solenoid goes, do I just lose that one gear, or all of them?

Thanks for the reply.

I forgot to say in my original post, if I am accelerating up to 80+KM/h and I back off the accelerator at the 70KM/h mark, the gearchange is a lot more smoother and there's no 'rev out'. Not sure if this changes anything but the more info the better.

Is a sticky solenoid something I should get fixed ASAP? Is my gearbox likely to blow if I don't? Also, could you possibly explain a solenoid in more detail for me? All I really know about them is that they tell the gearbox to change gear, basically?

Also, if a solenoid goes, do I just lose that one gear, or all of them?

Is the transaxle giving you any other problems, or is it just the shift into 4th that's harsh?

Going through the tech manual, it looks as though the underdrive solenoid might be the culprit, as it's only ever at full duty cycle when 4th ratio is selected.

If the problem occurs all the time, then it's fair to say that the solenoid is going to fail, either open or closed. If it does, then you'll get all sorts of bizarre gear ratios, and that could damage the trans.

The solenoids themselves are quite simple; they're pretty much just a magnet on a spring, and they open or close when the magnetic field is removed or applied.

Is the transaxle giving you any other problems, or is it just the shift into 4th that's harsh?

Going through the tech manual, it looks as though the underdrive solenoid might be the culprit, as it's only ever at full duty cycle when 4th ratio is selected.

If the problem occurs all the time, then it's fair to say that the solenoid is going to fail, either open or closed. If it does, then you'll get all sorts of bizarre gear ratios, and that could damage the trans.

The solenoids themselves are quite simple; they're pretty much just a magnet on a spring, and they open or close when the magnetic field is removed or applied.

Again, thanks for the reply.

With general day to day driving, ONLY 4th is a bit jerky. The rest of the gears are fine. However, going through all the gears in order (P -> L) it jerks around a bit (car stationary, foot on brake).

If the solenoid goes, is that it? All gears will be lost and the car won't even kick over?

How much would I be looking at to replace the solenoid? (Timing belt too :))

Simple standard question, what colour is the transmission fluid? If it's not bright pink, flush it.

Simple standard question, what colour is the transmission fluid? If it's not bright pink, flush it.

It's a reddy/cherry colour. Will check it again when I get to uni today (I didn't smell it last time either, will do those time).

do u have correct fluid??? sp3??? not standard atf????

Change your Timing Belt ASAP

Again, thanks for the reply.

With general day to day driving, ONLY 4th is a bit jerky. The rest of the gears are fine. However, going through all the gears in order (P -> L) it jerks around a bit (car stationary, foot on brake).

If the solenoid goes, is that it? All gears will be lost and the car won't even kick over?

How much would I be looking at to replace the solenoid? (Timing belt too :))

Does it drop into gear immediately after selecting a gear? If it doesn't, ie. it takes more than 2 or 3 seconds, and still clunks into gear, then you've got a problem with line pressure. That in itself could be the oil pump, or the valve body.

If the underdrive solenoid fails, in either the closed position, then you'll lose 4th gear as you know it. The trans will still try and produce a ratio, but it's anyone's guess as to what it could be. If it fails open, you'll still have 4 gears, but again, they'll be useless ratios.

The engine will still start, and you might be able to move the car.

Cost wise, you'll have to remove the valve body at the very least, and I'd say that most shops will want to remove the entire transaxle. I'll hesitantly say that you're looking at at least $500.