Originally Posted By: pacc
Originally Posted By: demarpaint
Originally Posted By: hardheaded
all my GM vehicals state to check them idling in park and trans hot.
I check my Jeeps the same way.
Supposed to make sure they are hot by driving it for an hour or two in regular traffic and let idle, as you say. As hot as possible for operation but not immediately after a highway trip, hence the idling.
I have a special dipstick for Chrysler vehicles which is calibrated in 5mm increments [IIRC]. I drive it for about 20 minutes or so. Then park it on level ground and let it idle about 3 minutes in park. I take the reading and write the number down from the dipstick, then get a temperature reading of the transmission fluid and compare it to a graph I have with the level and corresponding temperature. Both vehicles factory fill was dead on the money. If I service the transmission I measure how much fluid I drained, and add that amount back with fresh fluid. I idle the car and put the gear selector through each of the gears and hold it a few seconds. Put it in park, idle it for 3 minutes and get the readings again and tweak as needed. Then I'll take a ride and recheck the level. That method has been working well.
The fluid level rises as the fluid gets hotter, normal running temps is about 170F, but the chart depicts accurately the level for different temperatures. So even if the fluid is only 140F and the vehicle is on level ground, if I read the stick right and the chart right I'll get the level right, every time.
Originally Posted By: demarpaint
Originally Posted By: hardheaded
all my GM vehicals state to check them idling in park and trans hot.
I check my Jeeps the same way.
Supposed to make sure they are hot by driving it for an hour or two in regular traffic and let idle, as you say. As hot as possible for operation but not immediately after a highway trip, hence the idling.
I have a special dipstick for Chrysler vehicles which is calibrated in 5mm increments [IIRC]. I drive it for about 20 minutes or so. Then park it on level ground and let it idle about 3 minutes in park. I take the reading and write the number down from the dipstick, then get a temperature reading of the transmission fluid and compare it to a graph I have with the level and corresponding temperature. Both vehicles factory fill was dead on the money. If I service the transmission I measure how much fluid I drained, and add that amount back with fresh fluid. I idle the car and put the gear selector through each of the gears and hold it a few seconds. Put it in park, idle it for 3 minutes and get the readings again and tweak as needed. Then I'll take a ride and recheck the level. That method has been working well.
The fluid level rises as the fluid gets hotter, normal running temps is about 170F, but the chart depicts accurately the level for different temperatures. So even if the fluid is only 140F and the vehicle is on level ground, if I read the stick right and the chart right I'll get the level right, every time.
