Or 4L-65E, for you GMC folks... Good morning. I have a pretty good chance at checking my trans fluid level today. It looks nice and clean because I have been "exchanging the fluid" gradually. I realized it was overfill yesterday.. I did not feel the usual "rocketship"-like acceleration on the highway (70 to 80MPH snaps to pass New Yorkers) I usually do and, sure enough, the trans was overfill by about a quart. It feels the snappiest (fastest) when the level is spot on.

So, I siphoned out the old.. that old stuff (which is not that old, and can likely do some cleaning somewhere else) still looks a deep red, which is good.

My question is about the METHOD we all use to check the trans fluid. It is my understanding that everyone does so slightly differently. This morning, I, for the first ever time, checked mine cold. Some seem to check theirs after driving about 45 minutes. Some, after an hour and a half. Maybe some after two hours, or driving around most of the day.. I do remember something about letting it idle for about 5 minutes if you just got off the highway with it, and even "shift through all the gears twice, pausing 5 seconds" each gear..

Or, do you all just check it cold ??

Please chime in.

Also, I have Dex3 in mine ...

 

I follow a careful 3-step procedure:

1. Walk over to where it's sitting on the garage floor
2. Check if the puddle under it is still getting bigger
3. Determine that if it's still leaking, there must be fluid in it

 

Lmao...


I usually start it and let it run to running temperature, when hot I'll shift through each gear to move the fluid around, then pull dipstick wipe it clean, and then put in and pull out to read the level.