Mechanics

91 DX 4AFE / A131L (3 SPD) TRANSMISSION...

1991 Toyota Corolla

I own a '91 Toyota Corolla with 140K miles that recently experienced a transmission related failure. I have since pulled the engine and separated the transaxle from engine, inspected the torque converter, and believe it may be a torque converter problem.

The initial failure occurred while traveling at approx 25mph when there was a sudden grinding/banging noise from what sounded to me like the bell housing. The noise sounded like it was a rotational bang/scrape against the bell housing. I pulled over and had limited power with noise in all shift positions except park and neutral. The noise was present even while not moving and in gear. I was able to get it pulled back to my parking space (approx 1/2 mile). At no time while pulling the car did I exceed 10mph. The grinding/banging noise was also present while being towed in neutral with the engine running. The noise is also present while being towed in neutral without the engine running. While in park the noise is not present after initially starting the car and after shifting to neutral seems to " wind down".

- The fluid level was correct.
- The fluid doesn't smell burnt.
- The car didn't " slip" gears prior to the failure.
- When first starting the car immediately prior to failure, the car wouldn't have power in drive for a few seconds but then would run & shift fine.
- When I emptied the torque converter I did find very fine metal shavings.
- The fluid from the TC seemed to be darker/thicker than normal.
- The transmission had been flushed with a new screen installed within the previous 6 months.
- The TC looks like it has been remanufactured and has a 7 written on the housing.

Does this sound like a differential related problem or could this be simply a torque converter that has somehow parted out inside? Can they " part out" and produce a noise like this? The cost of a rebuilt transmission is prohibitive, but the cost of a JDM " low mileage" transmission may be an option. I have the transaxle out and can bring it in to a shop, but can a shop diagnose problems with a transaxle while it is removed from the engine? Also, would a shop have a way of checking the Torque Converter before I spend the $135 to try that route?

Thanks in advance for any advice or help.
Avatar
Pcpro
September 23, 2007.




Usually when the differential runs out of fluid you will get a grinding noise followed by the differential siezing.

The A131L has a seperate lubricant supply for the differential. The fill plug for the differential is on the rear near the firewall.

Also check the TV cable and make sure it is working and not kinked or binding.

Aside from the above, you would have to get the tranny checked at a shop. Another alternative is to buy a used A131L at a junk yard. You can usually find one for $300-400. Just make sure the used one has fluid in the differential and the TV cable is not broken.

I doubt a tranny shop would help much with the tranny out of the car, other than a disassemble and rebuild. They may be able to pressure test the convertor.

The problem I have had with JDM engines and tranny's is shipping. I bought an engine a few years ago and it arrived off the skid rolling around on the truck.
JDM engines of this era have EGR, while U.S. Engines are Federal (no EGR) or California (EGR).
So just make sure the tranny is compatable with your car.

Mmprince4000
Oct 19, 2007.


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