Correct Procedure for Transmission Level Check

[Deet27]

Going to do a Drain and Fill on my Transmission as i think it has started to slip, I know there is some slippage on a auto box but have just got it in my head and prob due a Drain and Fill  (come back to that later)

I want to make sure that I have the correct level so that when I do the drain and fill I can just measure what comes out to make it easier to know how much to put back in. I am doing the readings with engine running after cycling through all gears (twice) pausing for 2 seconds at each point and outside temp is approx 5ºc each time.

With engine Cold (Running for 2-3 Mins before reading) it Seems to barely on the dipstick, so that would mean that I need to top up?

Engine upto Temp after driving for 15 mins, 5 miles in daytime traffic, it would read right between the hot marks, so Correct level does not need topped up?

Engine upto temp after driving for 1hr, 30 miles daytime traffic, (idling for 3 mins before doing reading), would read over to hot mark by approx 1½cm, so level is to high and need to remove some trans oil?

 

My understanding is that I should do a reading after 15-20 mins of normal driving, but am concerned that  I am getting conflicting readings of Under-filled/Overfilled.

 

Would appreciate any advise 

[dave1]

Level should never be checked cold, check when engine has been running for 10/15 mins. The following link gives extremely good info on the subject.

http://www.agcoauto.com/content/news/p2_articleid/89

 

[Deet27]

Cheers for the link, Was getting concerned that with doing reading after 15 mins was OK but after doing a reading of driving 1hr+ was showing overfilled.

Car is used as Taxi and with doing mainly town driving wondered if oil was overheating/getting too hot.

Car shifts good seems to be fine however have noticed lately that on very gental acceleration the rev counter seems to sit at 2k revs as it goes through gears barely dropping as each gear changes. Unsure if that is an early indication that something is wrong.