How do you fix the automatic transmission of a 1992 Chrysler LeBaron convertible that only works in third gear?

Answer 1

Have a rebuilt trans installed/

• before going to the expense of a rebuilt trans there are two items that need to be checked first. the trans is controled by a computer that operates a set of externally mounted shift solenoids. either of these could cause the problem and they are much cheaper than a transmission.
• The transmission computer depends on input from two sensors, an input shaft speed sensor and an output shaft speed sensor. If the wiring to either of these, or the sensors themselves are faulty, the transmission computer will also default to this mode.

BEFORE you replace the tranmission, go to your Chrysler dealer and let him read out the transmission error codes. It could be "only" the solenoid valve block, that has errors or maybe the TCM transmission control module is faulty. You will find boht parts (solenoid and TCM) in eBay for a few bucks

-> if it only works in 3rd gear, the tranny has not to be replaced. Maybe the selector wires are blocked or unhooked, first check this an try to oil them a bit. Otherwise, the Solenoid and/or the Filters are blocked with sticky, old tranny oil (ATF) then first unplug the battery for at least 12 hours (to reset the TCMs settings), remove the Transmission solenoid at the front side of the transmission, at the front side of the car (4 long screws) and 1 electric connectior. clean the solenoid in petrol or with using a lot of WD40, specially clean the 8 little oil seaves specially, rebuild all and in 90 % of all cases, the tranny will work again for the next 100000 miles or so, unless everything gets sticky again.

The best is to replace the replaceable part of the 9 Litres of Transmission Fluid (only ATF+3 or similar, never, NEVER use Dexron)), you will only be able to replace about 4-5 Litres, and do not forget to replace the Transmission fluid Filter below the Tranny

The Chrysler A604/41TE (and newer) transmissions are much much much better than their reputation and I know many of them working up to 500000 kms / over 300000 miles without any problems.