1993 Toyota Corolla transmission problem.

1993 TOYOTA COROLLA
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SYAHRUL
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Transmission problem
1993 Toyota Corolla 4 cyl Two Wheel Drive Automatic
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Hi There,
I have a transmission problem past few month which is sometime 4th gear will not get into. I already service my transmission assembly by changging ATF oil & seal many times (3 times) but the problem still there. One day the thermostat spoil and i bypass/skip thermostat. So that now my car running without thermostat. Immediately after that my transmission problem SOLVED until today.No any problem. My question -
1. Is there any problem driving the car without thermostat ?
2. What is the link between thermostat and transmission?

Please Advice

Regards
Syahrul.
Aug 3, 2008 at 10:37 PM
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MMPRINCE4000
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Is this a A131L (3 speed with lockup) or a 4 speed (A420) transmission?


Running the car without a thermostat will cause the engine to run cooler than normal and prevent it from going into closed loop (where the ECM takes over fuel and ignition based on feedback from sensors). This will cause excessive fuel consumption especially in colder climates and can cause O2 failure and CAT failure.

The A131L shifting is controlled by a cable connected to the throttle body (TV cable) and the A420 is controlled by vacuum (I believe).

You may have solved the problem when you changed the trans. fluid, since there may have been some debris in the trans. that came out during one of the changes.

I would replace the thermostat (use a Toyota part) and see if it re-appears.
Aug 4, 2008 at 5:40 AM