87 MKIII transmission Problems

phzi · 06-26-2007, 12:06 AM

I purchased an 87 Supra a few months ago, which has been performing without issue until a few days ago. It's a 7M-GE, Automatic, only mods done to it are to the exaust and air filter.

A few days ago, the transmition stopped engaging smootly while in drive (Reverse was fine at the time) - occationally (not always) when at a full stop, and in drive, the car would not move forward when I took my foot off the brake. When applying a small amount of gas, the transmition would engage with a jolt (and a klunk noise). Higher gear changed didn't seem to be having any problems.

I turned the car on today, and put it in reverse, but it seemed to be acting as if the car was just in Neutral (could rev the engine, but nothing). After playing with the shifter for a minute, the car is now acting as if EVERY gear (other then park) is drive. When I put it in Neutral, or Reverse, the car will engage and drive forwards.

I've been ignoring a ECT errorcode since I got the car, (61 - Defective No2 speed sensor (in ATM)-severed wire harness or short circuit.) since the car has been driving fine (I presume relying just on the other speed sensor). So I'm not sure if this is actually relevent to my problem. I plan on doing some diagnostic work on it when I have a multimeter and some time handy.

Also, I'm not sure about the condition of the transmission oil. It doesn't look overly bad, but I don't know the last time it was changed. I am suspisious that the volume may be low, but I can't seem to get a measurement on the dipstick that actually means anything to me.

Anybody have any ideas or suggestions about where to start?

phzi · 06-26-2007, 01:49 AM

Just wanted to update with what I've figured out so far:

The Transmission functions normally in 1st/3rd/OD (L/2/D) when the ECU is unplugged, however, Neutral functions as if it was 1st, and Reverse seems to initially grab as if it was 1st, and then releases into what feels like park (revving the engine causes no movement).

When the engine is off, Neutral acts as normal.

Leads me to believe it's the transmission itself and not the electronics that are gone... however, I'm definitely not a car guy, so I'm hoping someone might be able to help solve my puzzle.

06-26-2007, 12:06 AM	#1
phzi Stock Join Date: Jun 2007 Location: Canada Posts: 2	87 MKIII transmission Problems I purchased an 87 Supra a few months ago, which has been performing without issue until a few days ago. It's a 7M-GE, Automatic, only mods done to it are to the exaust and air filter. A few days ago, the transmition stopped engaging smootly while in drive (Reverse was fine at the time) - occationally (not always) when at a full stop, and in drive, the car would not move forward when I took my foot off the brake. When applying a small amount of gas, the transmition would engage with a jolt (and a klunk noise). Higher gear changed didn't seem to be having any problems. I turned the car on today, and put it in reverse, but it seemed to be acting as if the car was just in Neutral (could rev the engine, but nothing). After playing with the shifter for a minute, the car is now acting as if EVERY gear (other then park) is drive. When I put it in Neutral, or Reverse, the car will engage and drive forwards. I've been ignoring a ECT errorcode since I got the car, (61 - Defective No2 speed sensor (in ATM)-severed wire harness or short circuit.) since the car has been driving fine (I presume relying just on the other speed sensor). So I'm not sure if this is actually relevent to my problem. I plan on doing some diagnostic work on it when I have a multimeter and some time handy. Also, I'm not sure about the condition of the transmission oil. It doesn't look overly bad, but I don't know the last time it was changed. I am suspisious that the volume may be low, but I can't seem to get a measurement on the dipstick that actually means anything to me. Anybody have any ideas or suggestions about where to start?

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06-26-2007, 01:49 AM	#2
phzi Stock Join Date: Jun 2007 Location: Canada Posts: 2	Just wanted to update with what I've figured out so far: The Transmission functions normally in 1st/3rd/OD (L/2/D) when the ECU is unplugged, however, Neutral functions as if it was 1st, and Reverse seems to initially grab as if it was 1st, and then releases into what feels like park (revving the engine causes no movement). When the engine is off, Neutral acts as normal. Leads me to believe it's the transmission itself and not the electronics that are gone... however, I'm definitely not a car guy, so I'm hoping someone might be able to help solve my puzzle.