Hi everyone. Greetings
Rently my 3 speed Auto transmission oil sump cover got damaged and oil leaked out. Without noticing, I drove the car few km. Later I replaced with new cover. During the process, I changed new FILTER, NEW OIL, GASKET etc. After that I noticed, during COLD start, the gear shifting from 1st to 2nd is not happening immediately (when the engine is COLD - starting after long breaks). For atleast one km the car moves only in 1st gear even i press the accelerator too hard... only the engine RPM goes up (4000 rpm also). After about 1 km the gear shift to 2 then to 3rd (I presume the transmission oil become hot now). This happens only during the cold start. Gear shift is normal during normal running.

I hope all you experienced friends can help me to understand why...

Thanks in advance.

Sawasdee!!! frum Thailand , Hmm well if its an 6G the transmission is a 4speed. yu may count onlee 3 because its already in first on take off. if the tranny sump was damaged possible things can occur , first make sure that the filter is tight , that is a definate , this is teh reason most kits come with new filter screws. second when looking at it make sure that the valve body was not damaged. There are 2 port lines that can sumtimes get damaged and cause shifting issues due to the low pressure in the line.

Secondlly transmission fluid levels need to be checked engine warm and turned off. Checking teh level with it running will give a false reading. Also with the pan off check the shift solenoid wires , they enter the lower front of the transmission case near the front of teh transmission sump and go to the shifter solenoids. Check that they are not frayed of slightly broken. The issue may be fluid related , lack there of or pressure. Lastly it may be a solenoid issue .