Transmission concerns

[Moggie]

I've owned the 92 SVX for only a few months and I live up in nothern Michigan, it has been a cold winter. My concern are:
1) the hard shifting into second and (a little less) into third. I'm currently using the "manual" button on the shift knob and this improves the hard shift, but it still goes thorough all the gears (not sure what manual is doing). Does running in manual hurt the transmission - what is this button supposed to do?
2) right around 70 mph the tranny (after it warms up) will shift in and out of overdrive, with the shift lever in manual or not. Is this the sign of problems or is this typical?
3) the car does not seem to shift into overdrive until the car has warms up. It can take 15 - 20 miles (the outside temp has been single digits and below). Is this typical and should I expect the poor gas milage because of this (20 mpg).

Moggie

[Crazy_pilot]

1) Not sure what your problem is. The manual button will hold the trans in a gear. ie; if "manual mode" is on and the shifter is in the 1 position, the trans will hold first gear to redline. In 2 the trans will not use first gear and will start in second, this is to assist traction on slippery surfaces by transmitting less torque to the wheels at launch. In D with manual on the trans will just shift normally.

2) and 3): That's the low temperatures causing your torque converter to delay lock up, or unlock occasionally.

Explanation: To lock the torque converter and get your ~60 MPH at 2K RPM the trans fluid must be warmed to a certain level. I think it's around 150*F. When you take off in the morning the fluid is cold and takes time to heat up. On the highway the fluid can be cooled too well at high speeds, causing the torque converter to unlock. It then builds a bit more heat from slipage and re-locks.

Yes, you can expect worsened fuel economy from this.

No, it's not a bad sign. Do you have a trans cooler installed? If so, that may be why it keeps unlocking at high speed, the trans cooler does it's job too well. I'm going through the exact same thing, it's regularly -20*C here these days.

[dcarrb]

One of mine had a wicked harsh 1-2 shift under moderate throttle, gear-hunted @40-60 mph, and seemed to apply power to the rear wheels inappropriately, just short of binding. A new throttle position sensor cured all.

dcb

[Moggie]

Chris & dcarrb,

Thanks for your reponse, it helped to clear up what I thought I was seeing. I look into the throttle position sensor.

Moggie

[Moggie]

I did check the transmission codes with the help of the fancy guide on the web page, it is 11 which is the duty solinoid A.

Also, the green "power" light does the 16 or 14 flashes each time I turn the car on. I've had the car for just 3 months and this has gone on from the start. Are both of these items the 25W 15ohm resistor by the battery or is the duty solinoid A more involved?

Moggie

[Chuckles]

It made more sense to me to just continue this thread, since I'm having a similar problem. My Trans seems to be slipping when I drive my car lately, it started abruptly yesterday and continued with greater frequency both directions of my cross town journey. This is the problem:

It feels the same as if I randomly disengaged my clutch and then reengaged it (not dumped, but in a general normal shifting manner). It’s as if my transmission thinks it’s in neutral, and then remembers I'm actually in drive (there is NO gear grinding). In manual mode I do not seem to experience this problem. I had just been messing with the TPS (or so I think it was) that black box opposite the throttle cables on the other side of the throttle bodies. The throttle response has been odd since I bought it, the last guy (who had no appreciation for this car) said it was probably the TPS that was making the response seem sluggish randomly. Any thoughts?

[Trevor]

As you have been messing with the TPS, I suggest that you refer to the how too section for exact info on cleaning and testing. First set it properly and go from there.